Think of your body as a "kinetic chain." The movement of your arms and legs actually begins with the spine, and that's why a strong core will help you in any sport.

If you want to take your sports performance to the next level, you'll make time for core workouts. For example, if you're a runner with strong legs, that's great. But if you ignore your core, the weak muscles in your hips and low back won't give your legs the support they need to carry you through longer or faster runs. Similarly, if you are a golfer, a stronger core body improves the stability to your arms and legs as you extend through the full range of motion in a golf swing.

The "bridge" is an easy core exercise that you can incorporate in to your pre-practice or competition warm-up.

Here's how to do it: Start by lying on your back with your knees bent and your feet flat on the floor. Don't press your back into the floor, but don't arch it. Keeping your back in this neutral position, lift your hips off the floor and engage your abdominal muscles. Lift your hips high enough to line up with your knees and shoulders, but remember to use your abs, not your glut muscles, to hold your hips high. Keep your arms alongside your torso, but avoid using your arms to raise your hips up. Take 3-4 deep breaths and release to the starting position. Be sure to keep your feet parallel to each other to avoid any strain on your knees.

A fitness ball is a useful item for core training. Most gyms have fitness balls available, or you can buy one to use at home. There are entire books dedicated to fitness ball workouts, but these three moves are some of the most effective.

Stability ball twist: Lie with your back on a fitness ball and your feet flat on the floor. Hold a small medicine ball between your hands and extend your arms up toward the ceiling. Keeping your butt on the ball, slowly rotate your torso to the right so that your arms are parallel to the floor and your knuckles are pointing towards the side wall. Hold to exhale, then slowly rotate back to the center and repeat on the other side. Start with a few repetitions to each side and work up to 3 sets of 10 repetitions.

Back extension on the ball: Start by kneeling behind the ball with your hands behind your head. Lean forward and lift your knees off the floor, curling your toes under so you are balanced on your toes with your torso resting on the ball. Raise your chest slightly, and then lower it down while keeping your spine straight from the tailbone all the way to your neck.

Crunch on the ball: Start by leaning back against the ball so it is supporting your torso, while your knees are bent and your feet are flat on the floor. Place your hands behind your head and curl upward so your shoulder blades lift off the ball, then lower your shoulders down.

Those who don't carry much fat around the middle may see the six distinct sections of the rectus abdominals, the long sheet of muscle that extends from your low belly to the area just below your sternum. All abdominal exercises work the whole muscle--you can't truly isolate "upper abs" or "lower abs." That said, some deeper muscle fibers will get more of a workout with certain types of abdominal exercises, such as those done on a stability ball.

The six sections of the rectus abdominals are not visible on most people, even those with low body fat, so it is more important to focus on strength than on whether you can see these sections. Don't get discouraged if your abs don't have that washboard appearance. Instead, remember that if you do abdominal exercises, the rewards range from better posture to a reduced risk of low back pain to stronger strength training workouts. You can strengthen your rectus abdominals using an abdominal machine if your gym has one, but some version of crunches on the floor or on a stability ball work just as well.

Other contributors to the appearance of six-pack abs are the internal and external oblique muscles that extend down the sides of the rectus abdominals. Keep in mind that simple twisting crunches, either on the floor or on a stability ball, will strengthen these muscles. There is no need to do side bends while holding weights or to do twists while holding a pole on your shoulders. Both of these moves can strain the lower back rather than strengthen it.

Core training is a fundamental part of overall fitness because a strong core provides a sturdy platform for all your sports activities, and for the activities of everyday life. Weak core muscles increase your risk of developing low back pain, poor posture and other muscle strains.

"Core stability" refers to the collaboration of the muscles in your pelvis, hips, abdomen and lower back working together to support your spine. Remember that there are many muscles in your trunk and pelvic area, and the best abdominal exercises are the ones that work multiple muscles simultaneously.

You can add core training exercises to your regular workout routines, or you can try these basic but effective exercises at home in the morning, before bed or anytime you have a few minutes to spare. But don't rush--focus on your form to get the maximum benefit.

Plank: Place your hands on the floor and extend your legs, then curl your toes under to lift your body away from the floor. Keep your hands positioned directly underneath your shoulders. Concentrate on pulling your belly in toward your spine, but keep breathing evenly. Hold this position for 20 seconds.

Crunches (or sit-ups): Crunch in whatever variation you like (with your legs up or flat on the floor). Start with 2 sets of 15 repetitions. Concentrate on engaging your abs muscles instead of straining your neck or pulling from your head and shoulders. The key is to focus on quality not quantity. Instead of 100 sloppy sit-ups, shoot for 30 in which you work through a full range of motion.

Increasing your functional fitness involves training core muscles. You may be strong and lean, but have trouble balancing on one leg. If so, start by adding some one-legged squats to your workouts a few times a week.

When you can handle a one-legged squat with ease, try this move that adds weights: place a small dumbbell on a level bench or chair. Do a one-legged squat and pick up the dumbbell as you come up. Too easy? Place the dumbbell on the floor and pick it up. This move helps train the different muscle groups to work together. Exercising with a fitness ball or wobble board also promotes functional fitness.

But it's important to remember a key difference between functional fitness exercises and standard strength training exercises: Form vs. Fatigue. When you are doing functional exercises, end your set when you can no longer maintain good form. As for standard strength training exercises, you may be working to the point of muscle fatigue.

To add functional fitness and stability exercises into your routine, ask a staff member at your gym to show you some options that are appropriate for your fitness level. Or if you work with a personal trainer and aren't already including stability exercises, talk about adding some. Of course, as when adding any new element to your workout, start easy and work up to tougher moves.

Terms like "functional training" and "functional fitness" are buzzwords for exercises that train different muscle groups to work together. The goal of functional training is to train your body to better carry out the activities of everyday life. By contrast, standard weight training focuses on strengthening specific muscle groups using targeted moves with free weights or machines.

It is worth incorporating some aspects of functional training into your overall fitness routine. Remember, just because you are toned and taut doesn't mean that you can't hurt your back while hauling a heavy suitcase. Functional exercise has a neurological component that weight training on a machine lacks because the machine is supporting your body. That's fine when you are working on a specific area, but don't forget about functional fitness, because it can improve your coordination, thereby reducing your risk of injury.

One example of a functional training exercise is a bent-over row (instead of using a seated row machine). Here's how to do it: Lean over a bench and place your left hand and left knee on the bench for support. Hold a weight in your right hand that you might use for a biceps or triceps exercise. Let your right arm hang straight down, then lift it straight up so your elbow points towards the ceiling, with your upper arm parallel to the floor. This move works the back, shoulders and arms, and is similar to movements that most people do every day, such as lifting groceries or children out of cars.