There is increasing evidence that strength/weight training can benefit adults interested in improving their health. Some of the known benefits include:
1. Reduced body fat. Strength exercise produced four pounds of fat loss after three months of training, even though subjects were eating 15% more calories per day. The final tally was: three pounds more muscle, four pounds less fat, and 370 calories more food per day (Campbell, 1994).
2. Avoid muscle loss that normally occurs as we age. Adults who do not strength train lose between five to seven pounds of muscle every decade. (Forbes, 1976; Rosenberg, 1992)
3. Avoid a drop in metabolism. The average adult experiences a 2-5% drop in metabolic rate every decade (Keyes, 1973; Rosenber, 1992). Adding three pounds of muscle mass increases resting metabolism by 7% (Campbell, 1994).
4. Improved glucose metabolism. Poor glucose metabolism is associated with adult onset diabetes. Glucose uptake improved 23% after four months of strength training (Hurley, 1994).
5. Reduced blood pressure. After two months of combined strength and aerobic training, participants in one study dropped their systolic blood pressure (the “top number”) by 5 mm Hg and their diastolic blood pressure (the “bottom”) by 3 mm hg.
6. Increased muscle mass. With just 25 minutes of strength exercise three days a week, people gain an average of three pounds of muscle over eight weeks. This is vital to weight control since one pound of muscle burns 35 calories per day, compared to only two calories per day burned by one pound of fat. This, in part, explains why a bodybuilder weighing nearly 300 lbs. can have a body fat of less than 5%.
But don’t give exercise too much credit for fat loss. Adding one pound of muscle burns just an extra fourteen calories per day (about one raisin) according to a study by Heber (The Resolution Diet, Garden City Park, NY: Avery Publishing Group, 1999).
7. Increased bone mineral density. Significant increases in the bone mineral density of the upper femur were demonstrated after four months of strength exercise (Menkes, 1993).
8. Improved blood cholesterol. Improvements in blood lipid levels are similar for both endurance and strength exercise (Hurley, 1994; Stone, 1982; Hurley, 1988).
9. Increased gastrointestingal transit time. Delayed gastrointestinal transit time (the time it takes for food to go from mouth to defecation) is related to an increased risk for colon cancer. Koffler (1992) showed a 56% increased transit time after just three months of strength training.
10. reduced joint pain. Strength training eases the pain of osteoarthritis and rhematoid arthritis (Tufts University Diet and Nutrition) and low back pain (risch, 1993).
11. Improved mood.