Kenneth Gardner
WEIGHT TRAINING exercises may be classified as isometric or isotonic. Each involves a different way of using and strengthening muscles.
Isometric or static exercises involve a muscle contraction, without a change in the length of the muscle. Isometric exercises may be performed with an immovable object such as a wall to provide resistance, or tightening your muscles without moving the position of your body or body parts. Isometric exercises do not develop strength throughout the entire range of motion of a joint.
For the maximum improvement in strength, isometric contractions should be held for about six seconds and repeated between five and 10 times each session. Isometric exercises require no equipment, so they can be done virtually anywhere. They build strength rapidly and are useful for rehabilitating injured joints. They should be performed at several different angles, for each joint to improve the entire range of movement throughout the joint.
Isotonic or dynamic exercises involve muscle contraction with a change in the length of the muscle. They may be performed with weight machines, free weights or your own body weight. Isotonic exercises may be performed with or without equipment. They are excellent for building strength, endurance and muscle bulk, as they work the joints through their full range of motion.
TRAINING SAFELY
Injuries do occur in weight training. Maximum physical effort, elaborate machinery, rapid explosive movements and heavy weights can be a recipe for disaster, if safety precautions are ignored. Each exercise has a proper technique that is important for obtaining maximum benefits and preventing injury. Exercises should be performed smoothly and with good form. Lift or push weights forcefully during the active phase of the lift and then lower them slowly with control. Perform all lifts through their full range of motion.
Spotters are necessary when an exercise has potential for danger. Spotters can assist you if you cannot complete a lift or if the weight tilts. They can also help to move a weight into position before a lift and provide help or additional resistance during a lift.
Weights should be kept as close as possible to your body.
Do most of your lifting with your legs, while you keep your hips and buttocks tucked in.
When you pick up a weight from the floor, you should keep your back straight, keep your head up, avoid bending at your waist and keep your legs straight.
Do not twist your body while you are lifting weights.
Lift the weights smoothly and slowly, and try to avoid jerking them, as you try to control the weights through the entire range of motion.
Do not bounce the weights against your body while you are trying to lift them.
You should not hold your breath while you are lifting, exhale when you are exerting the greatest force and inhale while you are moving the weight into position for the explosive phase of the lift.
Rest between each set of exercises to avoid fatigue, which will limit your ability to gain maximum benefits from the exercise. Fatigue is also a prime cause of injury.
You should maintain good posture to protect your back when you are doing standing lifts.
Lift weights that are within the limits of your strength.
Adjust the equipment to suit your body so that you do not have to work in an awkward position. Check the equipment to make sure safety devices are in place for your protection and the prevention of injuries.
Be aware of what is happening around you because most injuries result from inattention.
Always think safety first.
Kenneth Gardner is an exercise physiologist at the G. C. Foster College of Physical Education; email: yourhealth@gleanerjm.com.
