Kenneth Gardner

Weight training helps to develop muscular strength and endurance in the same way that endurance exercises help to develop the cardiovascular system. Muscles tend to adapt and improve their function when they are stressed by a greater load than they are accustomed to. The type of adaptation that occurs usually depends on the type of stress applied.

Muscles enable the body to move by exerting force on the skeletal system. When muscles contract (shorten), they move bones by pulling on the tendons that attach the muscles to the bones. Muscles consist of individual muscle cells called muscle fibers, which are normally connected in bundles. A single muscle (example biceps muscles) is made up of many bundles of muscle fibers.

Regular weight training causes the size of individual muscle fibers to increase by increasing their sizes. Muscle fibers are classified as fast-twitch or slow-twitch fibers according to their strength, speed of contraction and energy source. Slow-twitch muscle fibers are relatively fatigue resistant, but they don't contract as rapidly or strongly as fast-twitch fibers. The energy system that fuels slow-twitch muscle fibers is aerobic. Fast-twitch muscle fibers tend to contract more rapidly and forcefully than slow-twitch fibers but fatigue more quickly oxygen is very important in the energy system that fuels fast-twitch fibers, they rely more on anaerobic metabolism than do slow-twitch fibers.

Most muscles are normally composed of a mixture of fast-twitch and slow-twitch muscle fibers. The type of fiber that is used to execute a movement normally depends on the action of the movement. Endurance activities like jogging tend to use slow-twitch muscles fibers, whereas strength and power activities like sprinting use fast-twitch muscle fibers.

Weight lifting will increase the size and strength of both slow-twitch and fast-twitch muscle fibers, resulting in improved body movements.

Here are a few weight lifting exercises to help increase your muscle fibers.

The correct form is important in weight training. Here, exercise instructor, Kurt Dunn, performs reverse curls at Gymkhana at the Hilton Kingston hotel. - Rudolph Brown/Chief Photographer

OVERHEAD ABDOMINAL CRUNCHES (abdominal exercises)

Lie on your back on the floor with your feet flat on the ground and your knees bent.

Stretch your arms straight out over your head.

Crunch your upper body forward and bring your shoulder blades just off the floor.

Lower yourself to the starting position and repeat.

BARBELL LUNGES (leg exercise)

Place a barbell behind your neck and rest it across your shoulders.

Begin by striding forward with one leg to execute a regular lunge while keeping the other leg set in place.

Be sure to really stride forward so that you get a great stretch.

Bring the leg back to the starting position and repeat with the opposite leg.

UPRIGHT BARBELL DELTOID 0ROWS (shoulder exercise)

Stand with your feet shoulder-width apart.

Using a narrow overhand grip, grasp an EZ curl bar with both hands and let the bar and your arms hang down in front of your body, fully extended.

Raise the bar up to just under your chin, by flaring your elbows up and out.

Hold for a moment then repeat movement.

DIPS (chest exercise)

Find a set of dip bars and position yourself on them with your knees bent and your lower legs crossed.

Slowly lower your torso down to where your chest nearly touches the front of the dip bar and then return to the starting position.

Repeat movement until failure.