Fat Loss Success and Muscle
As you age into your 40s and 50s they say you suffer from furniture disease, where your chest falls into your drawers. Jokes aside, the progressive loss of muscle mass and function with age, called sarcopenia, could be a major cause of creeping obesity.
Fitness Professionals are in the box seat to help stem the tide of fat gain and Dr Robert Wolfe from the University of Texas Medical Branch has done the numbers to show you why.
His figures show that in young males, muscle mass ranges from 35 to 50 kg. In contrast, an elderly woman may have less than 13 kg muscle. For these vastly different amounts of lean tissue, muscle protein synthesis ranges from about 230 - 900 g per day.
This means that young men are turning over almost 1 kg of muscle every day and this process costs a lot more energy than in an elderly women. Wolfe estimates the energy used for muscle protein synthesis to range from 120 cal/day in the elderly woman to 485 Cal/day in your young male.
The difference in muscle protein turnover, 365 cal/ day, would lead to a gain or loss of 47 g of body fat per day, or 1.4 kg of fat per month. That’s 15.6 kg expected fat gain per year for the elderly woman versus a young male, simply due to a difference in muscle mass.
Wolfe shows that even a 10 kg difference in muscle mass translates into a difference in energy expenditure of about 100 cal/day or 4.7 kg fat mass per year.
Wolfe’s data provide a compelling case for maintaining muscle mass as you get older and also for the fat loss or fat maintenance benefits of weight training.
Matt O’Neill | Smartshape | Nov 2009
