You already spend lots of time training the obvious muscles. You know, the ones that look good in the mirror. But in the process, you might be missing the weak links in your body—little muscles that can mean the difference between a stellar on-field performance and a stumble, or worse, an injury. Get these overlooked players into the game by adding the following exercises to your regimen, and give your body a chance to show you what it can really do.

Mind

It doesn’t matter how hard you train if your head’s not in the game. Take it from Sarah Trowbridge, an elite rower who came up short in her bid to make the U.S. Olympic Team despite having some of the best stats around. She worked with Leah Lagos, Psy.D., a Manhattan-based clinical and sport psychologist, who spent a year teaching Trowbridge how to control her heart rhythms under stress, and get in touch with her prefrontal cortex, the part of the brain that helps you get “in the zone.” The result? Trowbridge nailed it at the last possible Olympic qualification trial, earning a spot in London 2012.

Try this: Before a game, count backward by seven starting from 997 for two minutes. “You can’t do it and worry at the same time. For that moment, you’ll feel more relaxed and not trapped in a ‘fight or flight state,” Lagos says. For a mid-game mental check-out, breathe in for four seconds and out for six seconds a few times to quiet the brain and calm the body. You can spot NBA players doing this on the court all the time.

Rotator Cuff

Blasting big weights on the Bench Press is great, but the tiny rotator cuff muscles in your shoulders are more important to tennis players, football linemen, swimmers, and athletes who throw.

Try this: Vonda Wright, M.D. and team doctor for the Olympic Sports Complex at the University of Pittsburgh recommends a four-exercise circuit that works the rotator cuff in every direction. Use a resistance band and do two sets of 10 reps for each move.

Shoulder Flexion: Start with one end of the band under your right foot and the other end in your right hand. Raise your right arm straight up overhead until the band is in line with your shoulder.

Cross-Body Abduction: With the band still under your right foot, hold the other end in your left hand and pull it diagonally across your body.

Scapula Retraction: Hold an end of the band in each hand, palms down. Pull your hands away from each other, squeezing your shoulder blades together until your arms are straight out.

Internal/External Rotation: Keeping your elbow against your body and bent at 90 degrees, rotate your arm away from your body and back. Repeat with the resistance on the opposite side. Switch arms.

Obliques

Your core is the steering wheel for the car that is your body. It drives your movements, but it wouldn’t go anywhere without your obliques. These side muscles help transfer power, keep you aligned and protect you from injury, says Polly de Mille, an exercise physiologist at the Hospital for Special Surgery in New York City.

Try this: Lie on your left side with your legs straight and your upper body propped on your left forearm. Raise your hips until your body forms a straight line. Hold for 30 seconds. Switch sides. Progress to 2-minute holds. Once you’re there, lift your top leg and hold it for the same duration. When that becomes easy, swing the leg back and forth. Aim to do one regular and two side planks (one on each side) a day.

Grip

How firmly your hands grasp can be the difference between carrying the ball to victory and a mortifying YouTube vid immortalizing your fumble on the goal line. But grip has serious performance implications in the gym, too. “To increase our potential to move big weights, we must create more tension,” says Jim Smith, CSCS. “A strong grip helps create and transfer more tension throughout the rest of your body. The tighter we can grip the barbell or dumbbell, the greater control we’ll have over the weights and the more muscle groups we can engage and get to work together to lift the weight.”

Try this: Dr. Wright suggests squeezing a tennis ball at least 30 times total in each hand three times a week. Or wrap a rubber band around the tips of your fingers then open and close your palm against the resistance, says de Mille.

Muscles Around the Ankle

Healthy ankles are hugely important to athletes in any sport requiring quick changes of direction—which, come to think of it, is most sports. Ankle sprains are one of the most common injuries among athletes. Making matters worse, once you experience that first sprain, you’re prone to suffer another one unless you rehab it properly. Better to avoid the injury entirely with the following ankle strength workout from Wright.

Try this: Sitting on the floor, loop a resistance band around your right big toe, then pretend to press on a gas pedal 10 times. Next, secure one end of the band to something sturdy (like a couch leg) and wrap the other end around your toe. Facing the couch, flex your foot toward your head 10 times. Rotate your body so that your left side is facing the couch, and rotate your foot to the right 10 times. Switch sides so that your right side faces the couch, and rotate your foot to the left 10 times. Repeat on your other foot. Do two sets of 10 of each move at least three times a week.