Table of Contents
- Highlights
- Introduction
- Recommended Exercise Methods
- Exercise's Effects on the Heart
- Exercise's Effects on Diabetes
- Exercise's Effects on Bones and Muscles
- Exercise's Effects on the Lungs
- Exercise's Effects on Weight
- Exercise's Effects on Other Conditions
- Complications
- Motivation
- Resources
- References
Strength or Resistance Training
Benefits of Strength Exercise. While aerobic exercise increases endurance and helps the heart, it does not build upper body strength or tone muscles. Strength-training exercises provide the following benefits:
- Build muscle strength while burning fat
- Help maintain bone density
Strength-training exercises are also associated with a lower risk for heart disease, possibly because it lowers LDL (the so-called "bad" cholesterol) levels.
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Click the icon to see an image of cholesterol. |
Strength exercise is beneficial for everyone, even people in their 90s. It is the only form of exercise that can slow and even reverse the decline in muscle mass, bone density, and strength that occur with aging.
Please note: People at risk for cardiovascular disease should not perform strength exercises without checking with a doctor.
Types of Muscle Contractions. There are three types of muscle contractions involved in strength training:
- Isometric contractions do not change the length of the muscle. An example is pushing against a wall.
- Concentric contractions shorten muscles. An example is the "up" phase of the biceps curl.
- Eccentric contractions lengthen muscles. An example is the "down" phase as weights are lowered.
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Click the icon to see an image of isometric exercise. |
Strength-Training Regimens. Strength training involves intense and short-duration activities. For beginners, adding 10 - 20 minutes of modest strength training two to three times a week may be appropriate. The following are some guidelines for starting a strength regimen:
- The sequence of a strength training session should begin with training large muscles and multiple joints at higher intensity, and end with small muscle and single joint exercises at lower intensities.
- You should perform both shortening and lengthening muscle actions. Emphasizing the movements that lengthen muscles is of increasing interest. This approach involves slowing and increasing the duration of these "down" movements. It appears to significantly increase blood flow, and some evidence suggests it may achieve stronger muscles more quickly. It may also improve heart function compared to standard movements. Exercises that lengthen muscles may be particularly beneficial for older people and some people with chronic health problems. This type of training increases the risk for muscle soreness and injury, however, and this approach is still controversial.
- Strength training involves moving specific muscles in the same pattern against a resisting force (such as a weight) for a preset number of times. This is called a repetition. People should first choose a weight that is about half of what would require a maximum effort in one repetition. In other words, if it would take maximum effort to do a single repetition with a 10-pound dumbbell, the person would start with a five-pound dumbbell. In the beginning, most people can start with one set of 8 - 15 repetitions per muscle group with low weights. As individuals are able to perform one or two repetitions over their routine, weights can be increased by 2 - 10%.
- Breathe slowly and rhythmically. Exhale as the movement begins. Inhale when returning to the starting point.
- The first half of each repetition typically lasts 2 - 3 seconds. The return to the original position lasts 4 seconds.
- Joints should be moved rhythmically through their full range of motion during a repetition. Do not lock up the joint while exercising it.
- For maximum benefit, allow 48 hours between workouts for full muscle recovery.
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Click the icon to see the proper way to breathe during exercise. |
Strength-Training Equipment. Unlike aerobic exercise, strength training almost always requires some equipment. Strength-training equipment does not, however, have to cost anything.
- Any heavy object that can be held in the hand, such as a plastic bottle filled with sand or water, can serve as a weight.
- Dumbbells (1 - 10 pounds) and resistance bands are inexpensive, portable, and effective.
- Wearable wrist weights help strengthen and tone the upper body.
- Ankle weights strengthen and tone muscles in the lower body. They should not be worn during high-impact aerobics or jumping.
- Hand grips strengthen arms and are good for relieving tension.
- A pull-up bar can be mounted in a doorway for chin-ups and pull-ups.
Previous Section
Review Date: 05/08/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine,
Harvard Medical School; Physician, Massachusetts General Hospital.
Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M.,
Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)




