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Archive for the ‘Exercises’ Category


BACKGROUND

It is generally believed that deep squats and ‘knees beyond toes’ increase the risk of lumbar spine and knee joint injury. ‘Sitting back into a chair’ and avoiding deep knee flexion, thus keeping the knees from moving past the toes in the bottom position, during a barbell squat, is usually recommended to minimize this risk. However, you’d be surprised to know that the opposite, in fact, seems to be true!

SCIENCE

Jerry Gamallo,Based on biomechanical calculations, the highest retropatellar compressive forces are seen at 90°. With increasing flexion, the wrapping effect, functional adaptations & soft tissue contact between the back of thigh and calf contributes to an enhanced load distribution and enhanced force transfer with lower retropatellar compressive stresses.

Studies comparing joint kinetics between when forward displacement of the knees was restricted vs. not restricted found that restricting forward movement of the knees minimizes stress on knees, but forces are likely, inappropriately transferred to the hips & lower-back; proper joint loading may necessitate knees moving past your toes!

TAKE HOME MESSAGE

Squat deep; don’t worry about knees beyond toes.

SOURCES

1. Hartmann et al. Sports Med., 2013.

2. Fry et al. J Strength Cond Res., 2003.

SPECIAL THANKS

To Jerry Gamallo of Venatõr Athletics, CA for allowing me to use his pictures.

PLEASE NOTE

This is more of a ‘stump article’; I have tried to keep it short and interesting. However, for those of you want more evidence, hold on to your horses – I will addressing this issue in more detail in the near future.

DISCLAIMER

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The whole town and his wife seems to be using whey protein.

Whey protein isolate – everybody knows – works; you know it works. It is the best protein for improving body composition (reducing fat while improving lean mass)! Or is it really?!

Whey protein isolate may be the best protein for you in most instances, that may not be the case always! Depending on your fitness goal, whey protein concentrate (and, even casein!) can sometime give whey isolate a run for its money. How is that?!

Well, read on to find out!

However, before we get into the nitty-gritty of which type of whey will best serve your purpose, let us get to know a bit more about why you should supplement with whey, in the first place.


Why should I take whey supplements?

Resistance training causes increase in muscle mass. This is due to increased muscle protein synthesis (MPS) that resistance training induces (Hulmi et al., 2009; Hakkinen et al., 2001; Hulmi et al., 2007). However, intense workouts alone are not enough to keep packing on lean muscle mass; you have to ‘stay anabolic’ most of the time to be able to keep that MPS working for you.

Without complicating matters, here’s a look at how resistance training increases lean muscle mass: a resistance training session causes muscle protein breakdown. This is then followed by repair of the damaged muscle tissue so that the muscles come out stronger the next time you hit the weights. For the muscles to get stronger, however, proteins ingestion (over and above normal needs) is crucial. Needless to say, the process of repair will suffer if you aren’t loading up on proteins.

That resistance training combined with protein supplementation causes muscle hypertrophy is well-documented (Moore et al., 2009; Hulmi et al., 2009; Cribb, Williams, Carey, & Hayes, 2006).  Ingestion of a whey protein supplement either immediately before or after a training session is – considered by some – to be the best for this purpose; also whey increases muscle protein turnover like no other protein. Furthermore, whey protein seems to work equally well in women as well (Josse, Tang, Tarnopolsky, & Phillips, 2010).

Another benefit of supplementing with whey is, improved post-workout recovery  This is likely due to the ‘anti-catabolic’ action of essential amino acids (Bird, Tarpenning, & Marino, 2006; Hoffman et al., 2010; Etheridge, Philp, & Watt, 2008).


What is Whey Protein?

You most likely know that whey is one of the 2 milk proteins – the other being casein. Casein is the more abundant of the two and it is casein that gives milk that white colour. In commercially available cow’s milk, 20% of protein is whey while the rest of it is casein (Hulmi, Lockwood, & Stout, 2010; Ha & Zemel, 2003; Etzel, 2004; Krissansen, 2007).

Whey is produced in large amounts as a by-product in the cheese industry. However, this whey has loads of fat, milk sugar (lactose) and salts in it and is not suitable for improving body composition.

During the process of whey purification, whey concentrate and isolate are produced sequentially. During the initial steps, larger molecules are separated out resulting in formation of whey concentrate. These larger molecules are proteins, lactose, immunoglobulins, amongst other less important ones. To produce whey isolate, cheese whey is passed through an ultrafiltration process (ion exchange or other methods). The ultra membrane filters fat, milk sugar (lactose), salts and other unwanted ingredients leaving behind a pure form of whey (Barile et al., 2009).

Hydrolysates, on the other hand, are formulations where large protein molecules are broken down into smaller fragments. The hypothesis is that this might further increase the rate of absorption of whey. However, this might not be totally true and hydrolysates may not offer much of an advantage over isolates or concentrates.


Types of Whey Protein

Whey is available commercially as either isolate or concentrate. ‘So, what’s the difference between them and which one should I be using’, you might want to ask?

The main difference between the two is the quality and the amount of protein content – isolate is purer and thus will contain almost 100% protein (well, 90-94% to be precise) while whey concentrate will contain protein ranging from 70-85%.

‘Well, that settles it – I am going with whey isolate!’, you might say. Hang on, not so fast! There is more to it than just protein content.


Comparing Whey Isolate and Whey Concentrate

Since whey isolate is higher in protein content, has a better amino acid ratio and thus bioavailability, it is absorbed into your system way quicker than whey concentrate (or any other protein, for that matter). That makes whey isolate the ideal post-exercise anabolic drink (Hulmi et al., 2009). Some researchers have suggested taking whey protein isolate before workouts as well in addition to your routine post-workout shake for maximum benefits (Esmark et al., 2001; Cribb & Hayes, 2006). Quicker absorption will mean almost instantaneous rise in blood amino acids which are then taken up by ‘hungry muscles’.

Having said that, the need for immediate post-workout protein supplementation in now being increasingly questioned (more below).

High protein content and higher quality of protein, however, that does not clinch the deal in favour of whey isolate. Concentrate has something up its sleeve that will make sit up and take notice!

As stated earlier, in comparison to isolate, whey protein concentrate will contain lesser amount of protein (in the range of 70-85%). However, somewhat similar to casein, whey protein concentrate will get absorbed slowly – this helps you stay anabolic for longer! Slower absorption also helps with absorption of other important nutrients from food like calcium. Not a lot of people know this but calcium plays an important role in causing fat loss (in addition to keeping your bones healthy)! Add to that the added benefit of appetite suppression for longer and casein suddenly become an important tool for your fat-loss goals or intermittent-fasting health journey…

Furthermore, whey protein concentrate is loaded with immunoglobulins – this helps boost your immune system and therefore may be beneficial in dealing with the intense stresses of training (especially if you happen to overtrain!).


Whey Isolate

Pros

    • pure; contains 90-94% protein!
    • purity means that it is great for gaining / maintaining lean mass while getting ripped (ideal when nearing competition or a photo shoot)
    • contains all essential amino acids in the best possible ratios
    • bioavailability for humans is best amongst all proteins – meaning, of the amount ingested, more is likely to be absorbed. For instance, in a scoop containing 25 g of whey isolate, almost all of the protein in there, will be going into your muscle
    • lightening fast absorption; ideal post-exercise drink – helps you get into the anabolic mode almost immediately

Cons

    • pricier than whey protein concentrate – to ensure purity, the commercial production of whey necessitates use of complex filtration procedure, hence the price
    • although whey isolate will help recovery after workouts, it loses out to whey concentrate in some respects. This is so because immune boosting constituents of milk protein like alpha – lactoglobulins and lactoferrins are removed during the purification process

Whey Concentrate

Pros:

    • lot cheaper than whey isolate
    • has a slower absorption rate than whey protein isolates; thus ensures a steady state of elevated amino acids in the blood and helps you stay anabolic for longer. This also reduces the need for frequent dosing
    • slower absorption helps with absorption of other important minerals like calcium and reducing blood glucose and lipid levels
    • induces appetite suppression which may help longer fasting interval, thereby improving body composition and metabolic disease parameters
    • contains immune boosting complexes (alpha – lactoglobulins and lactoferrins) which help post-exercise muscle recovery
    • helps fight diseases – for instance, chronic hepatitis C (Elattar et al., 2010)

Cons:

    • some amount of fat will be present so not ideally suited during times when keeping body fat% down is desirable
    • if you have any degree of intolerance to milk and dairy products, you might want to forget using whey concentrate on account of its lactose content – which is missing from the more purer whey isolate

TAKE HOME MESSAGE

In conclusion, isolate and concentrate are equally good – however, your circumstances – price, training goals and lactose intolerance – should tip the scales in favour of one or the other.


Recent developments

  1. More recently, the presence of a post-workout anabolic window (of opportunity) is being increasing questioned. ‘Not only is nutrient timing research open to question in terms of applicability, but recent evidence has directly challenged the classical view of the relevance of post-exercise nutritional intake with respect to anabolism’ (Aragon and Schoenfeld, 2013). The amount and quality of protein that you consume throughout the day is, now, thought to be more important than immediate post-workout whey ingestion.
  2. BCAAs (branched-chain amino acids – leucine, isoleucine and valine) may be overrated and ‘data do not seem to support a benefit to BCCA supplementation during periods of caloric restriction’ (Dieter BP, Schoenfeld BJ and Aragon AA, 2016).

Reference List

Aragon AA, Schoenfeld BJ (2013). Nutrient timing revisited: is there a post-exercise anabolic window? Journal of the International Society of Sports Nutrition. 2013;10:5 /1550-2783-10-5.

Barile, D., Tao, N., Lebrilla, C. B., Coisson, J. D., Arlorio, M., & German, J. B. (2009). Permeate from cheese whey ultrafiltration is a source of milk oligosaccharides. Int Dairy J, 19, 524-530.

Bird, S. P., Tarpenning, K. M., & Marino, F. E. (2006). Liquid carbohydrate/essential amino acid ingestion during a short-term bout of resistance exercise suppresses myofibrillar protein degradation. Metabolism, 55, 570-577.

Cribb, P. J. & Hayes, A. (2006). Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci.Sports Exerc., 38, 1918-1925.

Cribb, P. J., Williams, A. D., Carey, M. F., & Hayes, A. (2006). The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine. Int J Sport Nutr.Exerc.Metab, 16, 494-509.

Dieter BP, Schoenfeld BJ, Aragon AA.(2016). The data do not seem to support a benefit to BCAA supplementation during periods of caloric restriction. Journal of the International Society of Sports Nutrition;13:21. doi:10.1186/s12970-016-0128-9.

Elattar, G., Saleh, Z., El-Shebini, S., Farrag, A., Zoheiry, M., Hassanein, A. et al. (2010). The use of whey protein concentrate in management of chronic hepatitis C virus – a pilot study. Arch.Med Sci., 6, 748-755.

Esmarck, B., Andersen, J. L., Olsen, S., Richter, E. A., Mizuno, M., & Kjaer, M. (2001). Timing of postexercise protein intake is important for muscle hypertrophy with resistance training in elderly humans. J Physiol, 535, 301-311.

Etheridge, T., Philp, A., & Watt, P. W. (2008). A single protein meal increases recovery of muscle function following an acute eccentric exercise bout. Appl.Physiol Nutr.Metab, 33, 483-488.

Etzel, M. R. (2004). Manufacture and use of dairy protein fractions. J Nutr., 134, 996S-1002S.

Ha, E. & Zemel, M. B. (2003). Functional properties of whey, whey components, and essential amino acids: mechanisms underlying health benefits for active people (review). J Nutr.Biochem., 14, 251-258.

Hakkinen, K., Pakarinen, A., Kraemer, W. J., Hakkinen, A., Valkeinen, H., & Alen, M. (2001). Selective muscle hypertrophy, changes in EMG and force, and serum hormones during strength training in older women. J Appl.Physiol, 91, 569-580.

Hoffman, J. R., Ratamess, N. A., Tranchina, C. P., Rashti, S. L., Kang, J., & Faigenbaum, A. D. (2010). Effect of a proprietary protein supplement on recovery indices following resistance exercise in strength/power athletes. Amino.Acids, 38, 771-778.

Hulmi, J. J., Ahtiainen, J. P., Kaasalainen, T., Pollanen, E., Hakkinen, K., Alen, M. et al. (2007). Postexercise myostatin and activin IIb mRNA levels: effects of strength training. Med Sci.Sports Exerc., 39, 289-297.

Hulmi, J. J., Kovanen, V., Selanne, H., Kraemer, W. J., Hakkinen, K., & Mero, A. A. (2009). Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression. Amino.Acids, 37, 297-308.

Hulmi, J. J., Lockwood, C. M., & Stout, J. R. (2010). Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein. Nutr.Metab (Lond), 7, 51.

Josse, A. R., Tang, J. E., Tarnopolsky, M. A., & Phillips, S. M. (2010). Body composition and strength changes in women with milk and resistance exercise. Med Sci.Sports Exerc., 42, 1122-1130.

Krissansen, G. W. (2007). Emerging health properties of whey proteins and their clinical implications. J Am Coll.Nutr., 26, 713S-723S.

Moore, D. R., Tang, J. E., Burd, N. A., Rerecich, T., Tarnopolsky, M. A., & Phillips, S. M. (2009). Differential stimulation of myofibrillar and sarcoplasmic protein synthesis with protein ingestion at rest and after resistance exercise. J Physiol, 587, 897-904.

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cafe_neroGet off the Tube – straight into the nearest Cafe Nero  – pick up your favorite coffee and then off to work – isn’t that what most of us do?! Don’t we all love having our coffees, especially first thing in the morning? Yes, we do! – The reason being?! Well, for sure one of the reasons has got to be that coffee really ‘gets you going’ first thing in the morning. But, have you ever wondered how your innocuous looking cup of coffee manages to do that? Read on to find out more.

CAFFEINE

Let’s face it, we have to drink coffee every single morning coz somewhere along the line, we’ve got addicted to caffeine present in our coffee. It is this caffeine that is responsible for the ‘gets me going’ phenomenon!

It shouldn’t come as a surprise then that caffeine is the most ingested psychoactive drug (stimulant) in the world. It is a of major contents of almost all ‘stimulant’ beverages like tea, coffee, cola and energy drinks (not to mention thermogenic fat loss supplements).

According to Starbucks information on beverages, a tall latte’ contains 150mg of caffeine (filter coffee ‘venti’ – meaning twenty in Italian – is low in calories but contain a whopping 400mg per serving). Taking in that amount of the drug can have profound effects on your physiology.

What exactly are these effects and how does caffeine in your tall, skinny latte’ help you to get ‘switched on’, you might want to ask? Well, read on to find out more.

CHEMICAL STRUCTURE AND PHARMACOKINETICS OF CAFFEINE

But before we get into the intricacies of what makes caffeine tick, let us have a closer look at what caffeine really is. Chemically, caffeine is 1,3,7-trimethylxanthine.

Derived from the purine xanthine, methylxanthines have numerous medicinal applications, especially in lung disease. Apart from caffeine, other methylxanthines of note are theophylline, aminophylline (both of which are used as bronchodilators – in asthma), paraxanthine and theobromine. As you may have guessed, methylxanthines are  cardiac and CNS stimulants and bronchodilators (with individual variations, of course).

On ingestion, caffeine is expeditiously absorbed through the lining of the gastrointestinal tract. Within 15 minutes of consumption of coffee, trace levels of caffeine appear in blood; peak concentrations are reached within an hour 1.

Caffeine is highly lipid soluble (dissolves rapidly and completely in fat). Thus, it can cross cell membranes (of muscle and nerve cells), especially, the blood-brain barrier (a partition which allows only certain chemicals to enter the brain matter).

Caffeine exerts its action (as given below) on various systems through a number of proposed mechanisms.

After exerting its action, caffeine is broken down by the liver and kidneys – metabolites (break down products) that are formed are paraxanthine, theobromin and theophylline1. Incidentally, these metabolites have actions similar to caffeine as well – theophylline is considered even more potent!

ACTIONS OF CAFFEINE 

As mentioned previously, caffeine is the most often used stimulant in the world with prominent actions on the central nervous system as well as metabolism. As opposed to caffeine present in drinks, anhydrous form of caffeine (in the form of capsule/tablet/powder) is more potent.

Pharmacologically, caffeine is a competitive adenosine-receptor agonist, i.e. it serves as a competition for adenosine at its receptor. This receptor is responsible for suppressing neurotransmitters like adrenaline, nor-adrenaline, acetylcholine, dopamine and serotonin. Thus, ingestion of caffeine increases the production of these neurotransmitters.

However, since these neurotransmitters have complex and sometimes conflicting actions, effects of caffeine in endurance, strength and explosive sports (enhancement of performance, recovery and hydration) can be conflicting as well.

However, the main actions of caffeine can be described as under:

  • COGNITIVE EFFECTS

Caffeine improves wakefulness and vigilance. It may be also responsible for improved skill levels, especially those acquired through repeated training 2.

Foskett et. al. demonstrated in their study, improved cognitive parameters in athletes due to caffeine ingestion with enhanced sprint abilities as well as ball passing, ball control and accuracy associated with acute ingestion of caffeine3.

Because caffeine in low to moderate doses (3-6 mg/kg of body weight) has been shown to cause improved concentration during sleep-deprived spells, it may find application in services like the Special Forces 2.

  • THERMOGENIC EFFECTS

Consumption of caffeine causes stimulation of metabolism and a significant increase in the production of energy 4 – thermogenic action of caffeine has been shown to last for almost 3 hours after ingestion 4. Caffeine causes mobilization of free fatty acids and fat oxidation to produce energy during exercise 5-7. Additionally, it causes extra-muscular fat oxidation as well. Thus, caffeine seems to be definitely associated with causing fat loss 7.

These metabolic-stimulatory and fat-burning effects make caffeine a crucial ingredient of most fat-loss supplements (thermogenics).

  • ENHANCED EXERCISE ABILITY 

It is believed that caffeine enhances exercise performance. This is owing to its ‘glycogen-sparing effect’ – decreased utilization of muscle glycogen for energy during exercise – fats are used instead. Thus, owing to muscles glycogen lasting longer, the setting in of fatigue is prolonged.

Also, caffeine supports formation of new glycogen (glycogenesis) and thus aids in recovery after an intense exercise session.

Enhanced secretion of endorphins induced by caffeine is also a presumed mechanism in enhancing exercise performance 8 – the resultant decrease in pain perception leading to ‘feel good factor’ of beta-endorphins is well-documented 9.

In addition to the above findings, research also suggests that caffeine can improve neuromuscular transmission and muscle contraction 10;11 – both isometric and muscle endurance components are improved 10.

 To conclude, research overwhelmingly supports the view that caffeine enhances performance in endurance events 5;12, sports involving muscle power-strength components 13;14 as well as high intensity team sports 14;15.

TAKE HOME MESSAGE

So, the next time you are sipping that favourite coffee of yours, you know exactly what it is doing to you!

To sum up, caffeine has the following effects:

  • is more potent when ingested in the anhydrous state (as a tab/capsule/powder supplement rather than as coffee)
  • aids in sports performance
  • improves skills acquisition in sports – like ball control and passing
  • supports new glycogen formation (glycogenesis) and thus helps quicker recovery from an exercise session
  • prolongs exercise induced fatigue – by their ‘glycogen-sparing’ effect so you can keep going for a longer
  • improves neuromuscular transmission and muscle contraction
  • has thermogenic effects – stimulates metabolism causing burning of calories
  • induces fat loss – mobilizes fatty acids from fat stores and uses these as substrate (instead of glycogen) for producing energy
  • improves concentration – especially during sleep-deprived states
  • secretes beta-endorphins – makes you feel good

 References

  1.  Harland BF. Caffeine and nutrition. Nutrition 2000; 16(7-8):522-526.
  2. Lieberman HR, Tharion WJ, Shukitt-Hale B, Speckman KL, Tulley R. Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training. Sea-Air-Land. Psychopharmacology (Berl) 2002; 164(3):250-261.
  3. Foskett A, Ali A, Gant N. Caffeine enhances cognitive function and skill performance during simulated soccer activity. Int J Sport Nutr Exerc Metab 2009; 19(4):410-423.
  4. Astrup A, Toubro S, Cannon S, Hein P, Breum L, Madsen J. Caffeine: a double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers. Am J Clin Nutr 1990; 51(5):759-767.
  5. Ivy JL, Costill DL, Fink WJ, Lower RW. Influence of caffeine and carbohydrate feedings on endurance performance. Med Sci Sports 1979; 11(1):6-11.
  6. Erickson MA, Schwarzkopf RJ, McKenzie RD. Effects of caffeine, fructose, and glucose ingestion on muscle glycogen utilization during exercise. Med Sci Sports Exerc 1987; 19(6):579-583.
  7. Spriet LL, MacLean DA, Dyck DJ, Hultman E, Cederblad G, Graham TE. Caffeine ingestion and muscle metabolism during prolonged exercise in humans. Am J Physiol 1992; 262(6 Pt 1):E891-E898.
  8. Laurent D, Schneider KE, Prusaczyk WK, Franklin C, Vogel SM, Krssak M et al. Effects of caffeine on muscle glycogen utilization and the neuroendocrine axis during exercise. J Clin Endocrinol Metab 2000; 85(6):2170-2175.
  9. Grossman A, Sutton JR. Endorphins: what are they? How are they measured? What is their role in exercise? Med Sci Sports Exerc 1985; 17(1):74-81.
  10. Kalmar JM, Cafarelli E. Effects of caffeine on neuromuscular function. J Appl Physiol 1999; 87(2):801-808.
  11. Lopes JM, Aubier M, Jardim J, Aranda JV, Macklem PT. Effect of caffeine on skeletal muscle function before and after fatigue. J Appl Physiol 1983; 54(5):1303-1305.
  12. Hogervorst E, Bandelow S, Schmitt J, Jentjens R, Oliveira M, Allgrove J et al. Caffeine improves physical and cognitive performance during exhaustive exercise. Med Sci Sports Exerc 2008; 40(10):1841-1851.
  13. Woolf K, Bidwell WK, Carlson AG. The effect of caffeine as an ergogenic aid in anaerobic exercise. Int J Sport Nutr Exerc Metab 2008; 18(4):412-429.
  14. Beck TW, Housh TJ, Schmidt RJ, Johnson GO, Housh DJ, Coburn JW et al. The acute effects of a caffeine-containing supplement on strength, muscular endurance, and anaerobic capabilities. J Strength Cond Res 2006; 20(3):506-510.
  15. Schneiker KT, Bishop D, Dawson B, Hackett LP. Effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes. Med Sci Sports Exerc 2006; 38(3):578-585.

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Health and fitness professionals and researchers (me included!) have always cried hoarse about the downsides of obesity. For decades, obesity has been reported to impair health and reduce longevity (Allison et al., 2008). So much so, that research community has branded obesity as a disease (2008) which increases mortality and decreases longevity (Fontaine, Redden, Wang, Westfall, & Allison, 2003). There is, also, strong proof for causal effect of obesity in increasing mortality (4, 5). Conversely, calorie restriction (I don’t totally agree to calorie deficit plans – they aren’t for everyone!) to lower body weight has been shown to prolong life (Weindruch & Walford, 1988).

Notwithstanding the strong evidence for obesity being a curse, there are some curious findings about obesity in humans – those that will make you wonder if being fat is really that bad for you! There seems to be a reason why we gain weight as we age – well, in that case, does obesity afford some protective effect on human existence? Research into the so-called ‘obesity paradox’ certainly points in that direction.

Obesity Paradox

Obesity seems to have a protective effect in people suffering from a major injury or illness; this is called obesity paradox – in such individuals, being fat helps in that it increases survival time.

‘Among persons who already have heart failure, outcomes seem to be better in obese persons as compared to lean persons’ (Niedziela et al., 2014).  The direct causal relationship of obesity in this curious phenomenon is, however, a matter of intense debate (Habbu, Lakkis, & Dokainish, 2006).

Another equally curious observation reported by academicians is that lower body mass indices (underweight or those just under normal) are associated with an elevated mortality rate.  While individuals who are mildly overweight reflect the lowest mortality rates (Childers & Allison, 2010 and Niedziela et al., 2014). Mind you, the extremely obese are worse off though!

Take home message

Although ‘leaner is better’ may be true in most people – especially, in those who are disease-free and injury-free – obesity does seem to provide benefits in the diseased or injured, particularly in middle-aged individuals. This may be part of the reason why we put on weight as we age (Heo et al., 2003).

However, before you jump the gun and start advising middle-aged people to forget about getting lean, do keep in mind that there is, as yet, no conclusive evidence for the protection offered by being overweight or downright obese. Further research providing concrete proof needs to be conducted before we change our views on obesity.

Until that time, I’m afraid, its back to Olympic lifting platforms and HIIT and your nutrient-dense meals! Go people…!

 References 

Obesity as a disease: The Obesity Society Council resolution (2008). Obesity (Silver.Spring), 16, 1151.

Allison, D. B., Downey, M., Atkinson, R. L., Billington, C. J., Bray, G. A., Eckel, R. H. et al. (2008). Obesity as a disease: a white paper on evidence and arguments commissioned by the Council of the Obesity Society. Obesity (Silver.Spring), 16, 1161-1177.

Childers, D. K. & Allison, D. B. (2010). The ‘obesity paradox’: a parsimonious explanation for relations among obesity, mortality rate and aging? Int J Obes (Lond), 34, 1231-1238.

Fontaine, K. R., Redden, D. T., Wang, C., Westfall, A. O., & Allison, D. B. (2003). Years of life lost due to obesity. JAMA, 289, 187-193.

Habbu, A., Lakkis, N. M., & Dokainish, H. (2006). The obesity paradox: fact or fiction? Am J Cardiol, 98, 944-948.

Heo, M., Faith, M. S., Mott, J. W., Gorman, B. S., Redden, D. T., & Allison, D. B. (2003). Hierarchical linear models for the development of growth curves: an example with body mass index in overweight/obese adults. Stat.Med, 22, 1911-1942.

Niedziela J, Hudzik B, Niedziela N, Gasior M, Gierlotka M, Wasilewski J et al. The obesity paradox in acute coronary syndrome: a meta-analysis. Eur J Epidemiol 2014; 29(11):801-812

Weindruch, R. & Walford, R. (1988). The Retardation of Aging and Disease by Dietary Restriction. Springfield, IL: C.C. Thomas Publisher.

 

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Is there a connection between fitness and sexual activity? Would being fat and unfit prevent you from being a great bedroom performer? Chances are – YES; you can achieve much greater things by being leaner and fitter!

couple-holding-hands-intimately-in-bed

Which bring us to the question – could exercise be prescribed to those who want to improve their bedroom performance?! Shouldn’t functional training – which improves efficiency in carrying out our daily functioning – be doing the same for your love life as well? Well, it most definitely should!

Importance of sexual activity in human life

Feeding for one’s survival and indulging in sexual activity for the survival of one’s species are the most basic of all activities – for (almost) all life forms; human beings are no different!

Although even mentioning it, let alone discussing sexual intercourse is still a taboo is most parts of the world, it is an undeniable fact that sexual activity is an integral part of human existence. Thus, it is not at all surprising that striving to be ‘sexually desirable’ by the opposite sex is an inherent part of the human psyche.

Love making and a fit body

Almost everyone out there yearns a good-looking, lean companion, preferably someone with whom you enjoy great chemistry. Have you ever wondered why these qualities are foremost on everyone’s mind?

Well, because these qualities don’t just define physical appearance but have a deep-rooted meaning to them. Optimising chances of conception seems to be at the basis for all of these qualities that you seek.

What we are really looking for – while we may not know it, but these ‘likable qualities’ have been ‘genetically programmed’ in our subconscious minds – is this:

  • good-looking – carries high-quality genetic material
  • improved body composition – a lean waist and toned body with lower body-fat – physiologically and functionally more capable of the sexual act increasing the likelihood of a successful conception
  • right chemistry – the right kind of hormones (running through veins, as they say), the right psychosomatic connections and what-have-yous! Again, these will increase frequency and quality of sexual encounters and thereby, a successful conception

Now, if you are one of those who can read between lines, you will realize that all the above parameters – with the exception of genes, to a certain extent – can be improved by exercise. Agreed you can’t do much about your lack of a good genetic make-up  but – as any good coach will tell you – the ‘not-so-good genes’ shouldn’t stop you from ‘maximizing your potential’.

So here’s how exercise will help you with improving your ‘bedroom performance’ and turning your into a dream lover! But first, let’s see why the same fitness parameters that will improve your on-field sports performance will likely improve your bedroom performance too. And, regular indulgence in one may benefit the other.

Similarities between exercise and love-making

Since ‘lovemaking’ makes use of the very fitness parameters that typically epitomize short-burst interval training, it can be argued that either of these activities may help in improving performance in the other.

Here are some similarities (that I can think of):

  • Fitness parameters used

It is an undeniable fact that sexual activity is akin to exercise – with adrenergic system hyper-drive hearts pounding, blood pressure rising, breathing going haywire, sweating and what-have-you! Shouldn’t come as surprise really, when I tell you that you are using almost all the systems you’d use when working out – not to mention, hitting all components of fitness – cardiorespiratory fitness, muscle strength-power-endurance, et. al.

It should be a no-brainer that to improve your bedroom performance, you’ve got to improve your fitness.

  • Hormonal response

Testosterone is the major male sex hormone – it is instrumental in increasing libido, improving erections and sperm counts. Resistance training, – especially squatting – and HIIT boosts testosterone levels (Craig et al, 1989). Regular sexual activity has a similar effect – even watching porn – boosts testosterone secretion many folds over normal! Testosterone has prominent anabolic actions: helps pack on lean muscle mass, stimulates metabolism and improves body composition by decreasing body fat. This improved body composition, not to mention vigor, comes in handy (pun-unintended!) when it comes to your bedroom performance. Also, improved sperm counts will mean increased chances of conception

Read about the effects of low testosterone levels here.

  • Immune response 

Exercise and regular sexual activity have both been reported to cause increased levels of antibodies – improved serum antibody levels helps fight infections (Brennan and Charnetski, 2000). Studies have shown that those who indulge in sexual activity 2 to 3 times a week exhibited higher levels of IgA antibodies as compared to those who ‘do it’ infrequently (Charnetski and Brennan, 2004).

  • Calories burned

As we all know, exercise is a great way of burning calories over and above those required for your daily chores. Likewise, sexual activity is quite effective at burning calories as well (O’Keefe et al., 2010a;O’Keefe et al., 2011). It might surprise you to know that 30 minutes of intense ‘love-making’ can help you burn as many as 200 calories (O’Keefe et al., 2010b) which would equate roughly to about 15 min. of jogging on the treadmill or a entire weight-training session in the gym.

A word of caution here though: sexual activity alone cannot replace a calorie-deficit diet and being active through the day (improved NEAT – non-exercise activity thermogenesis) as the number one way of inducing fat loss.

  • Cardiac Function 

During a sexual act, you are operating intermittently at heart rates of 150 beats per minute and systolic blood pressures of 200 mm Hg. Thus, cardiovascular dynamics and workloads similar to short-burst interval training are mimicked.  This ‘heart rate training’ induced by sexual activity can, therefore, act as a great cardiovascular exercise and a metabolic-simulator! Conversely, regular sessions of short-burst interval training combined with weights can help you improve your ‘performance in bed’.

  • Busting stress and improving quality of sleep

Exercise and regular sexual activity – by virtue of secretion of endorphins and suppression of cortisone – improve mood, function and help fight stress. Prolactin secretion (which has a close association with sexual intercourse) also causes mood elevation. In addition to these, secretion of oxytocin and the phenomenon of ‘resolution’ – relaxation associated with orgasm – together will put you to a ‘peaceful sleep’. A restful sleep also ensure proper diurnal secretion of growth hormone.

Furthermore, reduced resting heart rates and diastolic blood pressure as a consequence of regular exercise and sexual activity keeps your stress levels reduced throughout the day.

  • Improved muscle tone

By increasing lean mass and decreasing body fat, exercise can help you get the most out of your ‘performances’. Strong pelvic floor musculature is of paramount importance in women as well as in men for deriving optimal pleasure.

Training to produce strong isometric contractions of the pelvic floor can help achieve better erections in males – being able to contract pelvic floor musculature intensely is one of the techniques recommended for treating erectile dysfunction. In women, strong pelvic floor – in combination with strong abdominals) is very crucial for expulsion of the baby during parturition (delivery) and with urinary incontinence, both during pregnancy and childbirth.

Regular sexual intercourse has also been shown to be beneficial in preventing prostate cancer.

TAKE HOME MESSAGE

To conclude, both – intense, short-burst interval training with resistance exercise thrown in – and regular sexual activity seems to utilize the same mechanisms and fitness parameters. Improving fitness will improve your performance in bed; regular sexual intercourse (and exercise itself) in turn will cause a plethora of health and fitness benefits.

References Cited

Brennan, F. X., and C. J. Charnetski, 2000 Explanatory style and Immunoglobulin A (IgA): Integr.Physiol Behav.Sci., v. 35, no. 4, p. 251-255.

Charnetski, C. J., and F. X. Brennan, 2004 Sexual frequency and salivary immunoglobulin A (IgA): Psychol.Rep., v. 94, no. 3 Pt 1, p. 839-844.

Craig BW, Brown R, Everhart J, 1989 Effects of progressive resistance training on growth hormone and testosterone levels in young and elderly subjects.  Mech Ageing Dev., v. 49, no. 2, p. 159-169.

O’Keefe, J. H., R. Vogel, C. J. Lavie, and L. Cordain, 2010a Organic fitness: physical activity consistent with our hunter-gatherer heritage: Phys.Sportsmed., v. 38, no. 4, p. 11-18.

O’Keefe, J. H., R. Vogel, C. J. Lavie, and L. Cordain, 2011 Exercise like a hunter-gatherer: a prescription for organic physical fitness: Prog.Cardiovasc.Dis., v. 53, no. 6, p. 471-479.

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00000SusThe worldwide prevalence of obesity has reached epic proportions. So much so, that calling obesity a pandemic wouldn’t amount to exaggeration! In addition to putting individual lives on the line, obesity has the ability to severely increase health care costs, negatively impacting on most economies of the world 1;2.

So, what is it that causes obesity – you might want to ask!


What causes obesity?

Well. traditionally, we have been told that ‘excess intake of calories coupled with decreased expenditure’ is the immediate cause of obesity. Excess calories are treated as reserve food material (read: fats) and deposited as triglycerides (TGs) inside adipose tissue (fat stores). However, having said that,it does not seem to be as simple as that.

Recently, it is increasingly being suggested (and, I am one of those who believes in this) that obesity may be a metabolic disorder where your nutrient metabolism goes for a toss. Also, rather than how many calories you consume, what kind of food you eat (and where the calories are coming from) will define if you stay lean or pack on weight; ingestion of nutrient-dense food is likely to make you leaner and healthier than foods that are only rich in calorie and poor in nutrients.

Also, a number of (as yet poorly understood) factors play a causative role: hormones, metabolic enzymes, metabolic rate, nutrient partitioning and calorie partitioning abilities of the individual. It must be emphasized here that the kind of food you eat will have a massive influence all of the aforementioned factors.

Anthropometric tell-tale signs of obesity are:

  • Increased waist circumference
  • Increased waist-hip ratio
  • Increased body mass index (BMI)

Adverse-effects of being Obese?

In addition to the much publicized ill-effects of obesity (given below), not many people are aware that obesity causes testosterone deficiency (TD) as well. Testosterone has a prominent effect on metabolism; deficiency can add to the problems. In addition, low levels of T can have a detrimental effect on a person’s psyche, making it hard to stick to a prescribed regimen of healthy food and exercise to counter obesity. Thus a ‘vicious cycle’ connection exists between obesity and low testosterone levels.

Well-known adverse-effects of obesity are:

  • Metabolic syndrome
  • Cardiovascular disease (CVD)
  • Diabetes Mellitus (Type 2 DM)
  • Hypertension (rise in blood pressure)

Testosterone deficiency and Obesity in Men

Testosterone (as the major male sexual hormone) is responsible for the male sexual and reproductive functions. However, not many people are aware that it plays a significant role in calorie utilization and metabolism as well. The exact mechanisms by which testosterone levels are affected in / contribute to obesity remain a mystery 3.

However, here are some interesting facts connecting testosterone to obesity are: testosterone:

  • causes nitrogen retention (read: increasing muscle mass, as part of the anabolic process) 3;4, low levels in obesity therefore cause loss of lean muscle
  • affects body composition in a positive way by reducing fat mass and increasing lean muscle mass 5, low levels therefore, reverse these effects
  • stimulates hormone sensitive lipase (enzyme responsible for fat breakdown), inhibits triglyceride uptake and mobilises fat from fat stores 6, low levels in obesity therefore, lead to increased fat deposition
  • an inverse relationship exists between parameters of obesity (WC, WHR and BMI) and plasma testosterone levels in an individual 3
  • an inverse relationship also exists between the ill-effects of obesity like metabolic syndrome, hypertension, type 2 diabetes and plasma levels of testosterone 7
  • number of studies report the irrefutable proof that low testosterone levels are connected with diabetes and cardiovascular disease 8;9
  • low levels of testosterone definitely connected with all-cause mortality 10

Thus, it can safely be said that testosterone is responsible for maintaining and increasing muscle while burning fat; low levels are responsible for fat deposition resulting in obesity, diabetes, cardiovascular disease, metabolic syndrome and increased mortality 3-5;7-10.


How can obesity be treated?

A number of strategies have been proposed by researchers, physicians and fitness professional to fight obesity. Some of these are:

  1. Calorie Deficit: This involves ‘dieting’, using liquid diets, etc. However, this causes loss of lean mass in addition to fat loss
  2. Calorie Deficit combined with Exercise: This maintains lean mass whilst causing weight loss, however a number of people have found this pretty hard to stick to
  3. Surgery (gastric binding or bariatric): effective but reserved only for the morbidly obese

A novel, effective method proposed for treating obesity is combining exercise and healthy diet with testosterone replacement therapy (TRT) – especially if accompanying signs and symptoms suggestive of hypogonadism are present. Additionally, as opposed to other modes of treatment, testosterone has the potential to elevate mood and energy and reduce fatigue 11.


Future research

Although TRT sounds like an exciting treatment option for tackling obesity, the plasma levels of testosterone at which therapy should be initiated remain undefined. Currently, it is recommended only in individuals diagnosed with testosterone deficiency (hypogonadism / erectile dysfunction).

A sad fact is that most doctors treating obese patients with diabetes or cardiovascular disease are not aware of the connection of testosterone with obesity and the potential benefits of testosterone therapy. Furthermore, the misconception that testosterone increases cardiovascular risk 12 and chances of pancreatic cancer prevents clinicians from prescribing testosterone 13.

There is a definite and realistic need to further explore this option for treating obesity in men. Also, an effort should be initiated to educate both doctors as well as members of the general population (who are struggling with obesity and its ill-effects) regarding the benefits of testosterone replacement therapy.


References

(1) Kypreos KE. Mechanisms of obesity and related pathologies. FEBS J 2009; 276(20):5719.

(2) Freedman DH. How to fix the obesity crisis. Sci Am 2011; 304(2):40-47.

(3) Traish AM, Feeley RJ, Guay A. Mechanisms of obesity and related pathologies: androgen deficiency and endothelial dysfunction may be the link between obesity and erectile dysfunction. FEBS J 2009; 276(20):5755-5767.

(4) Singh R, Artaza JN, Taylor WE, Braga M, Yuan X, Gonzalez-Cadavid NF et al. Testosterone inhibits adipogenic differentiation in 3T3-L1 cells: nuclear translocation of androgen receptor complex with beta-catenin and T-cell factor 4 may bypass canonical Wnt signaling to down-regulate adipogenic transcription factors. Endocrinology 2006; 147(1):141-154.

(5) Emmelot-Vonk MH, Verhaar HJ, Nakhai Pour HR, Aleman A, Lock TM, Bosch JL et al. Effect of testosterone supplementation on functional mobility, cognition, and other parameters in older men: a randomized controlled trial. JAMA 2008; 299(1):39-52.

(6) Traish AM, Abdou R, Kypreos KE. Androgen deficiency and atherosclerosis: The lipid link. Vascul Pharmacol 2009; 51(5-6):303-313.

(7) Dhindsa S, Miller MG, McWhirter CL, Mager DE, Ghanim H, Chaudhuri A et al. Testosterone concentrations in diabetic and nondiabetic obese men. Diabetes Care 2010; 33(6):1186-1192.

(8) Aversa A. Drugs targeted to improve endothelial function: clinical correlates between sexual and internal medicine. Curr Pharm Des 2008; 14(35):3698-3699.

(9) Cattabiani C, Basaria S, Ceda GP, Luci M, Vignali A, Lauretani F et al. Relationship between testosterone deficiency and cardiovascular risk and mortality in adult men. J Endocrinol Invest 2012; 35(1):104-120.

(10) Araujo AB, Dixon JM, Suarez EA, Murad MH, Guey LT, Wittert GA. Clinical review: Endogenous testosterone and mortality in men: a systematic review and meta-analysis. J Clin Endocrinol Metab 2011; 96(10):3007-3019.

(11) Saad F, Aversa A, Isidori AM, Gooren LJ. Testosterone as potential effective therapy in treatment of obesity in men with testosterone deficiency: a review. Curr Diabetes Rev 2012; 8(2):131-143.

(12) Traish AM, Kypreos KE. Testosterone and cardiovascular disease: an old idea with modern clinical implications. Atherosclerosis 2011; 214(2):244-248.

(13) Morgentaler A. Testosterone replacement therapy and prostate cancer. Urol Clin North Am 2007; 34(4):555-63, vii.

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For many-a-years, ‘treadmill-users’ in gyms – especially women – have been subjected to immense ridicule by those that swear by the resistance training method as the only way of training – there’s been an ever increasing tendency to criticise people using the treadmill or indulging in aerobic activities. The advent of CrossFit (and the Concept 2 Rower) hasn’t helped matter since CrossFitters have also jumped into the fray as the ‘treadmill bashers’.

The basis of the criticism springs from the thinking that lifting weights is far better than aerobic training when it comes to losing fat. Although much of the evidence for such thinking is anecdotal, the proof for the idea that ‘weight-training’ is far better than aerobic training – like treadmill runs – is flimsy to say the least. Yet, all ‘knowledgeable fitness experts’ seems to agree unanimously that weight training is far better than treadmill running for fat loss! Read my blog here on why I think resistance training may not be a great fat loss as is usually made out.

Notwithstanding what bodybuilders of CrossFitters might suggest, runners have always maintained that running (as in long-distance running) continues to be the best darn way to lose fat! Having said that, I have always maintained that running does come at a risk (of injuries); this is how I feel about long-distance running! However, this blog post is more about the fact that treadmill running seems to be a great fat loss strategy and yet, it seems to have copped a lot of unwarranted heat.

Argument(s) for Resistance Training

Lifting weights – also called resistance training (RT) – increases muscle mass and tone. This increase in muscle mass – since muscle is the most metabolically active tissue in the body – translates into more calories burned throughout the course of the day, even when resting, they say.

In short, resistance training bumps up your metabolic rate. This, they believe, is in contrast to aerobic training (AT) where you’d burn calories only when you exercise but nothing much after!

Not surprisingly, most ‘knowledgeable’ fitness experts – thinking along these lines – suggest RT over AT for burning fat.

Well, it just may be that  fitness gurus may have been wrong and those’ women on treadmills’ may have been right all along – if a new study, published in the American Journal of Physiology – Endocrinology and Metabolism is to be believed (Lee et al., 2013).

Evidence in Favour of Aerobic Training 

Researchers from the University of Pittsburgh, Pennsylvania, conducted a study comparing resistance training with aerobic training in young women (Lee et al., 2013). The results were astonishing (for most!) – to say the least! Apparently, not only is AT better than RT at reducing body fat % but it also wins hands down when it comes to:

    • improving cardiorespiratory fitness,
    • improving insulin sensitivity,
    • reducing visceral adipose tissue (fat surrounding organs),
    • reducing abdominal fat, and
    • reducing inter-muscular fat (fat within muscle)

Other studies have also supported the idea that aerobic training may be better at reducing visceral and abdominal fat, not to mention, the overall body fat%.

    • A study published in Dec, 2012 reported that while AT and combined AT/RT exercise programs caused more fat loss than RT alone, AT/RT and RT resulted in increased lean mass. However, although requiring a double time commitment over AT alone, a combined AT/RT exercise program, the authors observed, did not result in ‘significantly more fat loss over AT alone’ (Willis et al., 2012)
    • Another study published in the American Journal of Physiology – Endocrinology and Metabolism concluded that aerobic training caused significant reductions in body fat (including subcutaneous abdominal fat), visceral and liver fat, plasma liver enzymes, alanine aminotransferase (enzyme reflecting the amount of liver damage) and HOMA (Homeostasis Model Assessment – a measure of the level of your steady state beta cell function (%B) and insulin sensitivity (%S)). Resistance training, on the other hand, failed to significantly affect these variable. Also, AT was found to be more effective that RT at reducing abdominal as well as body fat (Slentz et al., 2011)

Aerobic Training and Metabolic Disease

An interesting observation is that aerobic training seems to be better than resistance training in reducing the risk of metabolic syndrome (obesity, diabetes, cardiovascular conditions and what-have-yous). Researchers from the Duke University Medical Center showed that the results of a combination of AT and RT exercise regimen – although more effective at reducing the risk of metabolic disease than RT alone – were not significantly different from AT alone (Bateman et al., 2011). This effectively suggests  that the RT component may be contributing very little to the disease prevention effect of an AT-RT exercise program

Why Women prefer Treadmills?

As if the results of the studies mentioned above weren’t shocking enough, here’s something that is even more thought-provoking – something that might answer your question of why women tend to favor treadmills over free-weights!

It appears that aerobic training is more effective in (overweight and obese) women than in men (Lee et al., 2013). Furthermore, there is some evidence to suggest that women enjoy AT more than RT (Lee et al., 2012)the opposite seems to be true with young men – they seem to enjoy RT more (now come on, do we even need any proof of that?!).

My hunch is that is that women find aerobic training more enjoyable because it is more effective for them! Not surprisingly then – call it nature or the subconscious minds at work – there seems to be a very valid reason why you see more women heading to the treadmill rather than the ‘free-weights section’!

Conclusion

It is likely that treadmill runs may be more effective than resistance training – especially in overweight women – for reducing body fat and preventing metabolic diseases. Also,

    • RT contributes very little (if at all) to fat-loss
    • RT contributes very little towards (metabolic) disease prevention
    • the above seem to be the job of the  good old aerobic training

Furthermore, as opposed to popular belief, a combination of aerobic and resistance training does not seems to afford any more benefits over aerobic training alone when losing body fat is your prime goal. So, out goes the almost ancient ‘fitness program’ of alternate days of weight training and cardio.

I reckon – in light of recent research findings – women are advised to get as much cardio under their belt as they can. After all, Jane Fonda did manage to get into top shape without too much of lifting, didn’t she?! So, if you feel like it, don’t let anyone stop you from jumping on to the treadmill, girls!

TAKE HOME MESSAGE

It appears that for overweight or obese individuals – especially women – aerobic training may still be the best way to go, not only to reduce body fat but also to reduce the risk of metabolic diseases as well.

Although, it can be argued here that studies cited have shortcomings (and a well-qualified researcher will likely, blow the results of these studies to smithereens), it has to be acknowledged these studies do have the potential to make us think twice.The question that begs to be answered is ‘what if we were wrong about our fat-loss strategies and indeed, about our obsession with resistance training and what if those women on treadmill were right all along?!

Until such a time that someone comes up with concrete proof about resistance training being so damn good that we can totally do away with aerobic training, let’s us keep our minds open. AND, let’s also stop ridiculing (or even downright laughing at) those women who hit the treadmill every single time!

References

Bateman, L. A., Slentz, C. A., Willis, L. H., Shields, A. T., Piner, L. W., Bales, C. W. et al. (2011). Comparison of aerobic versus resistance exercise training effects on metabolic syndrome (from the Studies of a Targeted Risk Reduction Intervention Through Defined Exercise – STRRIDE-AT/RT). Am J Cardiol, 108, 838-844.

Lee, S., Bacha, F., Hannon, T., Kuk, J. L., Boesch, C., & Arslanian, S. (2012). Effects of aerobic versus resistance exercise without caloric restriction on abdominal fat, intrahepatic lipid, and insulin sensitivity in obese adolescent boys: a randomized, controlled trial. Diabetes, 61, 2787-2795.

Lee, S., Deldin, A. R., White, D., Kim, Y., Libman, I., Rivera-Vega, M. et al. (2013). Aerobic exercise but not resistance exercise reduces intrahepatic lipid content and visceral fat and improves insulin sensitivity in obese adolescent girls: a randomized controlled trial. Am J Physiol Endocrinol.Metab, 305, E1222-E1229.

Slentz, C. A., Bateman, L. A., Willis, L. H., Shields, A. T., Tanner, C. J., Piner, L. W. et al. (2011). Effects of aerobic vs. resistance training on visceral and liver fat stores, liver enzymes, and insulin resistance by HOMA in overweight adults from STRRIDE AT/RT. Am J Physiol Endocrinol.Metab, 301, E1033-E1039.

Willis, L. H., Slentz, C. A., Bateman, L. A., Shields, A. T., Piner, L. W., Bales, C. W. et al. (2012). Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults. J Appl.Physiol (1985.), 113, 1831-1837.

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