A fullstomach could improve your appearance. Eating before you train speeds muscle growth, according to professional trainer and researchers. But the secret to more growth is consuming the right combination of nutrients to boost protein synthesis after a workout. Participants ate a 570-calorie meal consisting of 52 percent carbs, 34 percent protein, and 14 percent fat an hour before exercising.

Loop a towel over a pull-up bar and hold both ends with your right hand.

Grasp the bar with your left hand using an underhand grip so your arm is extended. Now pull yourself up with both hands. The separation between hands challenges your higher arm, so do 8 to 10 reps and then switch arms. If you’re having trouble, perform regular pull-up until you’ve worked up to this one.

A common supplement could help endurance athletes pull off a late-race push. Researchers say cyclists who took the amino acid beta-alanine had more power in a 30-second sprint following a long workout.

In the study, the cyclists rode for nearly 2 hours, and then performed a 10-minute time trial which revealed no advantage. But in a sprint afterward, riders who had taken beta-alanine showed 11 percent more peak sprint power output than a control group did. Beta-alanine boosts levels of carnosine in muscle cells, buffering muscle from fatigue during bursts of maximal exercise.

Try no more than 1 gram of slow-release beta-alanine capsules three or four times a day, for 8 to 10 weeks before your next competition.

This workout maximizes reps, giving multiple muscle groups a boost in little time. Start with 5 reps each of the first two exercises, back-to- back with no rest. Break for 1 minute, and repeat 2 or 3 times. Then do 6 reps each of the second two exercises, and repeat them without resting until your 15 minutes are up.

Step 1: Barbell Dead-lift

With your feet shoulder-width apart, bend and grab the bar with an overhand grip. Use your thighs and back to pull the weight up, keeping your shoulders and elbows locked and your back flat. Slowly lower the weight.

Step 2: Chin-up

Hang from a bar using a shoulder-width, underhand grip, your knees slightly bent and ankles crossed. Pull yourself up quickly until your chest touches the bar. If you have trouble, switch to a pull-down machine and use the same grip.

Step 3: Push-up

Assume a pushup position (hands slightly farther apart than your shoulders, your body in a straight line from ankles to neck). Quickly lower yourself until your chest touches the floor, and then forcefully thrust yourself up.

Step 4: Dumbbell Lunge

Stand with your feet hip-width apart, holding dumbbells at your sides. Step forward with one leg and lower your body until the other knee nearly hits the floor. Quickly push back up, switch legs, and repeat.