Some Fitness tips

• Try to Keep your weight workouts under an hour. After 60 minutes, your body starts producing more of the stress hormone cortisol, which can have a testosterone-blocking, muscle-wasting effect.

• Don't work your abdominal muscles every day. Your abs are just like any other muscle in your body, try to train them only 2 or 3 days a week.

• Try to test your body measurement in every 4 weeks, measure a variable—waist size, body fat, bench press—that equates to your end goal.

• Try to increase the speed of your running strides—not their length—to get faster. Your foot should always land under your body, rather than out in front of it, and you should push off with the toes of your rear leg for propulsion.

• Between sets, take 20 to 30 seconds to stretch the muscle you just worked. Boston researchers found that men who did this increased their strength by 20 percent.

• Don't worry about specific rest periods between sets. Instead, rest as you need it—less in your early sets when your muscles are fresh, and more as they become fatigued. "You'll cut your workout time between 15 and 20 percent," says Staley.

• Try to spend twice as much time stretching your tight muscles as your flexible muscles. "Focus on problem areas instead of muscles that are already flexible," says Bill Bandy, Ph.D., a professor of physical therapy at the University of Central Arkansas. Typical problem areas for men: hamstrings, shoulders, and lower back.

• Drink low-fat milk. Scientists in Canada found that people who consumed more than 600 milligrams of calcium a day—roughly the amount in 2 cups of milk, a cup of broccoli, and a half cup of cottage cheese—had lower body fat than those who consumed less than 600 milligrams a day.

• Try to lift light weights fast to build strength. Your muscles will generate as much force as if you were lifting a heavier weight more slowly. Try it with the bench press: Use a weight that's 40 to 60 percent of what you can lift one time, and do eight sets of three repetitions, pushing the weight up as fast as possible. Rest 30 seconds between sets.

• Try to go faster for shorter distances to improve your running form. You'll not only perform better, but you'll also be less susceptible to injuries.

• Try skip the treadmill warmup before lifting weights. Instead, do a warmup that targets the muscles you'll be using. For a full-body warmup, grab a bar and do two sets of 10 repetitions each of the squat, deadlift, bench press, and bent-over row.

• Try to do squats and deadlifts . . . to build your abs. Research shows that these two exercises force your abdominal muscles to do a significant amount of work to maintain your posture.