Isometric: Isometric exercises are very safe because the intensity can be adjusted quickly and precisely. These exercises are very quick and do not produce any discomfort. Consult a qualified healthcare profession in patients with a history of heart problems because isometric exercises drastically reduce the blood flow to the muscle. In turn, blood pressure rises and reduces the amount of blood that is able to flow back to the heart.

Isotonic: While generally safe, isotonic exercise can make the muscles sore due to the stress the muscles experience while they lengthen. In addition, the muscles do not equally benefit from this type of exercise. Instead, the muscles that benefit the most are located at the weakest point of action.

Isokinetic: Isokinetic exercises are generally safe. Since the machines used measure the user's resistance, the danger of lifting more weight than the amount that can be safely handled is eliminated. These exercises increase strength in all muscles evenly, and it is the quickest way to increase muscle strength.

General: A qualified healthcare provider should be consulted before beginning any new exercise program.

Like all workout routines, weight training should begin with a warm-up session and end with a cool-down segment that includes stretching exercises.

Use a spotter when lifting heavy weights.

If dizziness, pain, nausea, shortness of breath or chest pain occurs stop the exercise and contact a qualified healthcare professional before resuming the exercise routine.

After completing a weight-training workout, wait 24-48 hours before lifting with the same muscles.

The benefits of exercise are widespread, both physical and emotional. Clinical trials have shown that strength training of all sorts effectively helps build muscle strength and provides many health benefits. For instance, weight training may prevent osteoporosis, coronary heart disease and diabetes as well as reduce risk of fatigue and depressive symptoms. Exercise also increases joint mobility and endurance. It may delay signs of aging, help with cardiac rehabilitation, muscle rehabilitation (after an injury), general health and endurance.