The 100 Squats A Day Challenge: Body Weight Squats Get Kids in Shape in Less Than 3 Minutes. Plus: Will Sitting Around Kill You, No Matter How Much You Work Out?

I know this photo from motivationblog.org borders sexism, but you must understand ladies: Men are simple and lazy folks and you know about the importance of squats, anyways, right?

No, you're not mistaken exercise and fat loss science (at least statistically your favorites) in a single blogpost. And as if that was not already enough, two of my favorites are also part of the game: For one thing the subjects in the latest study from the National Institute of Fitness and Sports in Kanoya, Kagoshima, Japan deals with ways to tackle childhood obesity and for another thing, the results are quite impressive, despite the ingenious simplicity of the approach the scientists used to improve the body composition, increase the fitness level and build muscle strength and size in their adolescent study particpiants:

Do 100-rep body weight squats everyday after school!

For the ninety 13.7 ± 0.6 boys who participated in the study this meant that they were squatting to parallel for roughly 3 minutes 4-6 times per week, without extra weight.

Now you are probably thinking about some of the pampered and fattened Chinese children and how a body weight squat for them equals your 5-RM max, right? As unfortunate as it may be that this could in fact be the case, we are talking about Japan, here - not China - and our young subjects were by no means sedentary couch potatoes. On the contrary, they were 100% average Japanese school boys from a pilot school in Kagoshima (Japan). There were kids who played table tennis (n = 12) and volleyball (n = 11), participated in track and field (n = 5), and Japanese archery (n = 8) in the active arm of the study and baseball (n = 24) and soccer (n = 22) players, as well as boys who were swimming(n = 5) and practicing kendo (n = 3), regularly. In fact,

"[t]he number of times participating in a week and duration involved in their athletic activities in a day were 5.0 ± 2.0 days/week and 2.4 ± 0.9 h/day respectively."  (Takai. 2013)

And what's more, all of the active students did take part in competitions at a regional level. The effects you see in figure 1 were thus not of the "Biggest Loser" variety.

Figure 1: Changes in body composition (left) muscle size and strength (right) in adolescent boys after 8 weeks of doing 100 body weight squats 4-5x per week  (Takai. 2013)

Ok, the total amount of body fat, the boys lost was not earth shattering, but contrary to the aforementioned "biggest losers" there was not much be lost in the first place; plus, and this is really important, whenever we are talking about body recompositioning in adolescents. The effect was highly squat-specific and not a result of a group specific growth spurt (body height increased 6-7% in both groups in the course of the 8 weeks.

Let's not forget: There is more to physical culture & health than fat loss!

I know that fat loss probably is the "sexiest" benefit the (almost daily) squat episodes had, but let's not forget about the rest, i.e.

• increases in lean body mass,
• increases in muscle thickness and strength of the knee extensors, and
• improved vertical jump height. 

 Which are certainly enough to validate the scientists conclusion that this simple and above all highly practical "exercise regimen" is a ...

"feasible and effective method for improving body composition, the strength capability of the knee extensors and jump performance in adolescent boys." (Takai. 2013)

I guess few of you will consider themselves "adolescent boys" any longer. Thinking of my 90-year old grandpa who did his squats and push ups every morning and made the German Sports Batchwith ease even in the summer before he passed away, I am however pretty sure that you will be hard pressed  to find a man or women of any age who would not benefit from something as practical and time-efficient as doing 100 squats every morning before they hop under the shower.
The only thing that startles me is the absence of increases in sprint performance. It's difficult to say, but if you take a closer look at the baseline sports the participants were engaged in, my best bet is that the 24 baseball and soccer players in the control group, or rather their sports-specific training regimen are responsible for the difference. On the other hand, if we expand on this thought of confounding factors that may skew the study results, we would also have to expect that these boys should have major "fat burning advantage" over their table tennis, volleyball and esp. Japanese Archery counterparts in the active group. That being said, on a level playing field, the effect size may, in fact have been even more pronounced if the scientists had simply randomized the participants to the squat ad control groups.

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If you also have something to hold to and do underhand chins, you can do a whole and in fact very effective full-body even when you are traveling. I mean, you still remember that the underhand pull-up is a formidable biceps exercise, as well (learn more)?

Bottom line: Much in line with the astonishing fat loss results Smith et al. observed in already fit crossfit athletes (cf. "Crossfit Your Way Down from 16% to 8% Body Fat"), the study at hand provides further evidence in favor of "light" full body workouts or plyometrics (cf. "Building the Jack-of-All-Traits Legs Workout With Squats, Jump Squats and Body Weight Plyometrics"), not necessarily as a replacement, but rather as an adjunct / way to diversify your habitual routine.

Tweaks / adjuncts like these may well be able to rekindle and maintain constant progress - especially in terms of physical conditioning and explosive performance. Not to mention that adding 50 push ups and pull-ups to the equation would make a perfect "travelers workout", which can be performed wherever you can bring and install a doorway pull-up bar. And if you can't do 50 in a row, just use a rest pause technique: Do as many as you can, rest, take 10-12 deep breaths and continue counting from where you stopped in your previous "set" until you hit the targeted rep range.

References:

• Celis-Morales CA, Perez-Bravo F, Ibañez L, Salas C, Bailey ME, Gill JM. Objective vs. self-reported physical activity and sedentary time: effects of measurement method on relationships with risk biomarkers. PLoS One. 2012;7(5):e36345.
• Chaput JP, Lambert M, Mathieu ME, Tremblay MS, O' Loughlin J, Tremblay A. Physical activity vs. sedentary time: independent associations with adiposity in children. Pediatr Obes. 2012 Jun;7(3):251-8.
• George ES, Rosenkranz RR, Kolt GS. Chronic disease and sitting time in middle-aged Australian males: findings from the 45 and Up Study. Int J Behav Nutr Phys Act. 2013 Feb 8;10:20.
• Henson J, Yates T, Biddle SJ, Edwardson CL, Khunti K, Wilmot EG, Gray LJ, Gorely T, Nimmo MA, Davies MJ. Associations of objectively measured sedentary behaviour and physical activity with markers of cardiometabolic health. Diabetologia. 2013 Mar 1.
• Kwon S, Burns TL, Levy SM, Janz KF. Which Contributes More to Childhood Adiposity-High Levels of Sedentarism or Low Levels of Moderate-through-Vigorous Physical Activity? The Iowa Bone Development Study. J Pediatr. 2013 Jan 7.
• Mark AE, Janssen I. Relationship between screen time and metabolic syndrome in adolescents. J Public Health (Oxf). 2008 Jun;30(2):153-60.
• Smith MM, Sommer AJ, Starkoff BE, Devor ST. Crossfit-based high intensity power training improves maximal aerobic fitness and body composition. J Strength Cond Res. 2013 Feb 22. 
• Takai Y, Fukunaga Y, Fujita E, Mori H, Yoshimoto T, Yamamoto M, Kanehisa H. Effects of Body Mass-Based Squat Training in Adolescent Boys. Journal of Sports Science and Medicine. 2013; 12:60-65.
• Wijndaele K, Duvigneaud N, Matton L, Duquet W, Delecluse C, Thomis M, Beunen G, Lefevre J, Philippaerts RM. Sedentary behaviour, physical activity and a continuous metabolic syndrome risk score in adults. Eur J Clin Nutr. 2009 Mar;63(3):421-9. Epub 2007 Oct 31.