Photo: Howard Wise

Playing sports and hitting the gym can be totally separate activities, but it doesn't have to be that way. Whether you're just starting out with a new sport or have been hitting the field since your school days -- you'll go further and faster if your gym routine compliments your inner athlete.

"You'll feel more body confident, prevent injuries, and improve your overall athletic performance if you use sports-specific resistance training two to three days a week in addition to regular workouts," says Tom Williams, former U.S. Olympic swimmer and owner of Burn Fitness health club in Santa Monica, Calif.

Here, Williams offers simple training tweaks for four of the most common hobbies and fit pastimes: Swimming, running, cycling and playing golf or tennis. After two to four weeks of incorporating these specific moves into your regimen and practicing your sport, you'll have a stronger core, a leaner lower body, faster reflexes and the ability to play better with more stamina.

Swimming
Swim a minimum of twice a week, but train not only with your favorite stroke (free-style, for instance), alternate it with other strokes, including a backstroke and the butterfly because each specific movement really zeroes in on different muscle groups and works your body in new ways.

Moves: Yoga side planks, ab crunches and push-ups also boost your swimming muscles and core strength. Williams recommends using a resistance band or dumbbells to strengthen the muscles all around your upper and outer back. In addition to a gym lat pull-down machine or a chest bench press, stand upright and tie a tube or band handle around a bed post or use dumbbells to row back with arms straight until hands reach hips. Return arms to full extension and repeat 10 times.

Photo: Leon Wilson, Flickr

Running
If you run at least twice a week, try to differentiate runs by duration and intensity: If you do a short, fast 20-minute run on Monday, for instance, do a longer or a more hilly run on Thursday for 40 minutes or so. Play with tempo, speed and consistency, urges Williams.

Moves: Do calf-raises and standing leg lifts to strengthen the thighs. Also, add stair climbing to build explosive power in the lower body, and add power jumps on the stairs, too, jumping up on the bottom step to switch legs repeatedly. Also try this: Stand at the bottom of any stairway and place right foot on the second step with arms at your side. With speed and power, lift right knee upward until it reaches your chest and slowly lower back down, repeat up and down 10 times. Repeat on the other side.

Golf and Tennis
Perform your favorite weekend-warrior hobby as often as you can, but play with a tennis pro or golfer who has more advanced skills than yours. Book yourself one session with a specialist and watch your game soar! Also, do ab-strengthening moves or rent ab-toning DVDs to enhance stability around your spine and add endurance to your swings and strokes.

Moves: Sit on a large stability ball, bend knees 90 degrees, bring feet flat on floor, and extend a weighted ball or 5-pound dumbbell directly over your head with palms facing up. Lift right right arm close to the ear at full extension (palm faces into your head) and take the medicine ball or dumbbell in the left hand to lower it behind your head and down, keeping elbow forward and close to the ear. Lift back up and down 10 times, then switch hands and repeat. Lie back on the stability ball for ab crunches, biceps curls and elbow-cross crunches, too.

Cycling
If you cycle several times per week, one of those workouts should be short and fast to work on speed training; at least one of these bike routines (whether outdoors or in a gym) should be using hills (or hill training on a stationary bike) to enhance your muscular endurance and lower-body power. Change it up each time you put your pedal to the metal -- and really challenge your body. Try a Spinning class to kick-start a super-stale routine.

Moves: Begin in the start position for a standard push-up and try taking one limb at a time off the ground while stabilizing through the core -- it's tough! Also do elbow plank exercises and yoga sun salutations to stretch out the body. Since you're forced into a forward bend for long amounts of time during cycling, stretch this area to soothe the mid-back with yoga Cobra pose and Upward Dog.

Here are more quickie workouts to boost performance in your sport of choice!