Exercise Won’t Make You Thin? Yeah Right.

exercise won't make you thinTime magazine and writer John Cloud bought themselves a fight with the Aug 9 cover story Exercise Won’t Make You Thin. Howls from medical professionals, personal trainers, and their nemesis – the people who moan they “exercised for four hours a week and never lost a pound” – are still ringing.

Time argued:

  • Exercising just makes us hungrier, which means we eat more, AND
  • Because we’ve exercised we “reward” ourselves with the chocolate pastry or muffin we would not have otherwise had, immediately undoing the calorie loss we’ve earned with our workout session (women are apparently the worst “overcompensators”.)
  • We’re being “tricked” into unpleasant and useless exercise and while we are just getting hungrier and fatter. (Look at national obesity figures.)

The resulting pros-and-cons discussion has thrown up some great research clarifying whether exercise gets you thin, keeps you thin or both.

The short conclusion is it depends on what sort of exercise (aerobic, weights etc) you are doing. And while it may not help you lose weight,  it certainly will help you stay that way.

Diet to Lose, Exercise to Maintain

 

Two studies in particular show clearly that while diet may play a bigger part than exercise in losing weight, exercise plays an essential part in maintaining that loss.

One 12 week study by Kramer, Volek et al,* which included aerobic, strength training, and diet controls, showed fat mass losses from the three approaches as follows:

  • Diet only: 6.7kg,
  • Diet/aerobics/cardio: 7kg,
  • Diet/aerobics plus weights/resistance: 10kg.
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Most noteworthy – the group that combined diet, cardio and resistance training lost almost no lean tissue whereas the diet only group lost almost 3kg worth of lean tissue.

Training was 3 times a week starting at 30 mins and progressing to 3 x 50 minutes over the 12 weeks. So the weight training group lost 3.3 kg, (21.1lbs,) – 44% and 35% more than diet and aerobic only groups respectively –  in the same time frame.

We’ll deal with study number two – which examined the lifestyles of people who had taken off large amounts of weight and then successfully kept it off – in Instalment 2 of Exercise Won’t Make You Thin Successful Losers.

*Kramer, Volek et al., Influence of exercise training on physiological and performance changes with weight loss in men. Med. Sci. Sports Exerc., Vol. 31, No. 9, 1999.