"Faster, higher, stronger" is the Olympics motto, and elite athletes train their entire lives for a shot at a medal.
However, exercise training is important even for non-athletes because the ability to generate strength and power is essential for good quality of life.
I define exercise as an increase in physical activity or work significantly above rest.
When you exercise, a few important body changes occur:
■ Heart rate and blood flow increase.
■ Active muscles use stored sugar and fuels mobilized from fat and liver.
■ Activation of muscles produces heat, so core temperature increases.
Exercise comes in many forms, and each provides unique benefits to the body.
Cardio is exercise maintained over a period of time — activities like running, swimming, dancing. Cardio works larger groups of muscles at the same time compared to weight training, but the muscles work at a lower intensity.
Doing cardio at least 30 minutes a day three times a week can improve heart function, increase capillary supply to muscles, and improve sugar and fat burning in muscles. Newer studies are showing that cardio can increase brain cell activity with benefits in learning and mental health.
Weight training focuses on increasing strength and size of targeted muscles. It is higher-intensity exercise performed over a short time, putting a load on a muscle group to challenge those muscles to get stronger.
Balancing strength around a particular joint is important for preventing injuries. For example, if you strengthen the knee extensor muscles (quads), you also should strengthen the knee flexor muscles (hamstrings) to maintain a strength balance across the knee joint.
Loss of strength is a major concern for the aging population. Thus, we recommend some forms of strength training in daily life for everyone regardless of age.
Stretching and flexibility training is complementary to cardio and weight training. Improved flexibility can decrease risk of injury. Stretching is a passive movement — skeletal muscles are not activated. Stretching can increase range of motion around a specific joint.
By maintaining muscle function and strength, we are going to be healthier, but we don't know the specific reasons why. Skeletal muscle health affects our mobility but is also important for metabolic health. Skeletal muscle stores up to 90 percent of all sugar in our bodies, so it is the major site insulin targets after a meal. Recently, a study by the Harvard School of Public Health found that men who lifted weights at least 21/2 hours a week decreased their risk of getting type 2 diabetes by a third.
A sedentary lifestyle has profound negative health consequences besides obesity and heart problems. New research links loss of muscle strength to declines in clinical outcomes — as our muscles weaken, we are more likely to get sick and die. Conversely, newer provocative research in animals has also shown that if muscles are kept healthy, this leads to longer lifespan.