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NEW YORK (Reuters Health) - Getting enough protein and moderate amounts of fat from food may help older men's muscles respond better to weight training, a study suggests.
Researchers found that among 45 middle-aged and older men who went through a strength training program, those with more protein in their diets tended to have a greater short-term increase in testosterone levels right after their workouts. This hormonal response, in turn, was related to greater gains in muscle mass over 21 weeks of weight training.
The findings suggest that adequate protein -- in the form of low-fat dairy and lean meat, for example -- will help older men optimize their strength training, lead investigator Dr. Janne Sallinen told Reuters Health. Sallinen, of the University of Jyvaskyla in Finland, and colleagues report the findings in the International Journal of Sports Medicine.
It's known that people need sufficient calories and protein for their muscles to respond well to strength conditioning. As men age, their muscle mass and testosterone levels gradually wane; but there has been little research into how diet affects older men's hormonal responses to weight training.
For the current study, Sallinen's team had 45 men, ages 49 to 73 years, go through 21 weeks of supervised weight training. Half of the men also received nutritional counseling; they were encouraged to eat high-fiber grains, fruits and vegetables, as well as lean meat, fish and low-fat dairy.
The researchers found that, among men in the diet-counseling group, higher levels of dietary protein were related to greater testosterone responses to strength training.
Other studies, the researchers note, have found that high-fiber, low-fat diets may lower men's testosterone levels. However, in this study, men in the counseling groups boosted their fiber and carbohydrate intake and cut their total fat intake without lowering their testosterone concentrations.
This suggests that as long as fat intake is moderate -- about 30 percent of daily calories -- such diets will not affect testosterone levels, according to the researchers.
The bottom line, Sallinen said, is that getting the recommended moderate amount of fat in the diet, along with enough protein, may help older men create a muscle-building "hormone environment" to support their workouts.
This does not, however, mean that older men should take protein supplements, Sallinen pointed out. Instead, the study suggests protein from food is enough.
SOURCE: International Journal of Sports Medicine, December 2007.