Monday, June 8, 2015

Weights or Cardio? What's the Best Visceral Fat Burner + How Often, Long and Intense Do You Have to Train

You don't have to be super fat to have sign. amounts of inter-organ fat.
Visceral or organ fat is the nasty stuff that's "proctecting" your organs from harm... well, as long as it the way you live (bad dietary habits + no exercise) don't increase its volume and weight to abnormal levels.

On the outside, people with high amounts of visceral fat can look anything from significantly obese to normal-weight (particularly if they're wearing the right clothes); and yet, normal-weight obese (skinny fat) individuals, as scientists call these people, do still have a similarly increased risk of diabetes, cardiovascular disease and all the other nasty diseases you can develop when your visceral fat floods your body with pro-inflammatory cytokines.
HIIT is an excellent way to shed both subcutaneous and visceral body fat!

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

30s Intervals + 2:1 Work/Rec.

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

HIIT Ain't For Everyone
Against that background, it stands out of question that the questions Xiao and Fu tried to answer in their latest review of the literature is relevant for millions of people - questions like these:
  • How does the type of exercise affect its effects on visceral obesity?
  • How much training (volume) does it take to shed visceral fat?
  • Do you have to train intense or light to maximize visceral fat loss?
Ah, and obviously there's the question I mentioned in the headline, already: Is strength or aerobic training the optimal visceral fat burner? In view of the fact ...
"[...] there are very few researches focused specifically on the effects of resistance training (RT) on visceral fat, and even these studies have reported different results" (Xiao. 2015)
this is not exactly an easy question to answer. A two-year work by Schmitz et al. (2007) actually found an increase in visceral fat by 7% with RT (although this was significantly less than the 21% increase observed in their inactive controls). Davidson et al.  (2009), found no effect of resistance training on visceral fat and so on and so forth...
Figure 1: While Sigal et al. found no effect on total body fat, both the aerobic and resistance training regimen in their study produced measurable reductions in abdominal visceral fat (Sigal. 2015).
There's still no reason to give up on resistance training as a visceral fat eliminator, though, Davidson et al. had their subjects train only 20 minutes of RT, three times a week, which is probably too little to have a significant effect and and Sigal et al. (2007 | see Figure 1) found similar effects of aerobic and resistance training on visceral fat. Similar results as in the Sigal study were observed by Slentz et al., who found both aerobic and resistance training (3 days/wk, 8 exercises, 3 sets/exercise, 8–12) produces similar anti-obesity effects as aerobic training.
If you want to lose sign. amounts of body fats with strength training (only) you must diet! The most obvious reason that resistance training alone won't help (esp. overweight) people lose body fat is the relatively low amount of energy that's expended during the (often short) workouts in the average study. So, either you train at higher volumes and more frequently, or - and that's the superior approach - you use your diet (25-35% deficit; 2g/kg body weight protein) to lose body fat and (high intensity) strength training to conserve muscle mass | learn more
In conjunction, the results of the few available studies do yet still supports the notion that (in a non-calorically restricted scenario) a low training volume as it was used in the Davidson study may not expend enough energy to trigger sign. reductions in (visceral) body fat.

Whether you will or won't lose visceral fat w/ any form of exercise may thus depend on volume and intensity - for both, it appears as if a threshold would exist.

Some research believe that while any form of exercise will have beneficial effects in reducing total body fat, a higher volume of physical activity would result in a higher reduction of VAT (cf. Friedenreich. 2011). Personally, I tend to agree with McTiernan et al. (2007) and Irwin et al. (2003), though. Both say that you have to train five to six times per week for 45 to 60 min each to see sign. results in the absence of significant energy restriction.
Figure 2: While more exercise (higher duration) helps more for total body fat loss (left), only those of the highly active subjects that also had significant improvements in fitness lost more visceral fat (right | Irwin. 2003).
That there is a minimum of exercise required to produce sign. fat loss in the absence of dietary interventions does yet not mean that "more helps more". If we put faith in the self-reported exercise levels of the subjects in the McTiernan et al. and Irwin et al. studies, though, their results indicate that a mere increase in the training volume does not automatically lead to a greater decrease in visceral fat - for total body fat, however, this may be different (see Figure 2 | left).
Don't forget to diet! The leaner you are, the more important your diet will be. Many TV-shows and magazines still try to fool people to believe that you could get a cover-model look with nothing but (albeit) intense exercise. For most people, i.e. everyone who does not watch his diet strictly, anyway, this is unfortunately not the case. So, if you want to lose fat (visceral or not) start correcting your dietary mistakes first and work on your workout routine later.
In their review, Xiao and Fu argue that a similar "threshold" as it was observed by McTiernan et al. and Irwin et al. for the total exercise volume may exist for the exercise intensity, as well - albeit without being able to define a clear "cut off for exercise intensity":
"A substantial evidence also exists to prove that risk for metabolic syndrome is decreased with increase in physical activity. On the contrary, Gutin et al, . (2002) demonstrated the lack of a significant effect of physical training intensity on decrease in total body fat and visceral fat deposition. Very few studies such as that of Irving et al. have shown the impact of exercise intensity on abdominal visceral fat in obese adults wherein the abdominal fat was a primary outcome parameter. To summarize, studies demonstrating the effect of physical training intensity on visceral fat deposition as a primary objective have been lacking" (Xiao. 2015).
Gender-specific differences, as they have been observed by Redman et al. (2007), who found men lose sign. more visceral fat in response to a combination of aerobic exercise and calorie restriction than women, make it even more difficult to compare the results.
30 Min of Exercise Can Avoid Costly & Unhealthy Gestational Diabetes + Using a Measuring Tape to Judge Visceral Fat Mass. Update: Vitamin D, Age & Obesity | more
Eventually, it turns out that it is - as so often - impossible to give a one-size-fits-it-all answer to the question whether resistance or aerobic training is the better visceral fat burner. If there are no diet- and life-style interventions involved, though, it would appear as if aerobic training has the better scientific backing. Whether that's not a mere result of the comparatively higher energy expenditure is yet about as difficult to answer, as the question whether visceral fat loss really requires 4-5x 40-50 minute exercise sessions per week if you train at more than moderate intensities.

All things considered, it may be a good idea to remember the results of the Irwin study which indicates that anything that improves cardiovascular fitness will also trigger significant visceral fat loss (and improvements in lipid and glucose metabolism). In short, training your fitness will take care of your (visceral) fatness | Comment on Facebook!
References:
  • Davidson, Lance E., et al. "Effects of exercise modality on insulin resistance and functional limitation in older adults: a randomized controlled trial." Archives of Internal Medicine 169.2 (2009): 122-131.
  • Friedenreich, C. M., et al. "Adiposity changes after a 1-year aerobic exercise intervention among postmenopausal women: a randomized controlled trial." International Journal of Obesity 35.3 (2011): 427-435.
  • Gutin, Bernard, et al. "Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents." The American journal of clinical nutrition 75.5 (2002): 818-826.
  • Irwin, Melinda L., et al. "Effect of exercise on total and intra-abdominal body fat in postmenopausal women: a randomized controlled trial." Jama 289.3 (2003): 323-330.
  • McTiernan, Anne, et al. "Exercise effect on weight and body fat in men and women." Obesity 15.6 (2007): 1496-1512.
  • Redman, Leanne M., et al. "Effect of calorie restriction with or without exercise on body composition and fat distribution." The Journal of Clinical Endocrinology & Metabolism 92.3 (2007): 865-872.
  • Schmitz, Kathryn H., et al. "Strength training and adiposity in premenopausal women: strong, healthy, and empowered study." The American journal of clinical nutrition 86.3 (2007): 566-572.
  • Sigal, Ronald J., et al. "Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes: a randomized trial." Annals of internal medicine 147.6 (2007): 357-369.
  • Slentz, Cris A., et al. "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." American Journal of Physiology-Endocrinology and Metabolism 301.5 (2011): E1033-E1039.
  • Xiao, T., and YF FU. "Resistance training vs. aerobic training and role of other factors on the exercise effects on visceral fat." Eur Rev Med Pharmacol Sci 19.10 (2015): 1779-1784.