1. It strengthens the heart. The heart is a muscle. Like other muscles, its performance improves when it's regularly challenged by exercise. The heart responds to exercise by becoming stronger and more efficient. Strengthening the heart muscle can help ward off heart disease -- the leading cause of death in the United States, according to the U.S. Department of Health and Human Services -- even in early childhood.
Even very vigorous exercise—like the interval workouts Gibala is studying—can, in fact, be appropriate for people with different chronic conditions, from Type 2 diabetes to heart failure. That’s new thinking, because for decades, people with certain diseases were advised not to exercise. Now scientists know that far more people can and should exercise. A recent analysis of more than 300 clinical trials discovered that for people recovering from a stroke, exercise was even more effective at helping them rehabilitate.
10. It enhances emotional well-being. Most people report that they feel calm and have a sense of well-being after they exercise. Exercise, according to one theory, releases beta-endorphin, a natural substance in the body that is hundreds of times more potent than morphine. Another theory points to serotonin as the cause of the exercise high. Increased levels of serotonin in the central nervous system are associated with feelings of well-being, heightening of appetite, and lessening of mental depression. The weight loss that accompanies exercise can also cause people to feel better about themselves.
Not feeling up to heavy lifting? Try doing more reps at a lower weight instead and you’ll be kissing that arm fat goodbye in no time. Researchers at Canada’s McMaster University studied a group of 20-something men over a 12-week period, with half the study subjects lifting heavy weight and doing low reps, and another group lifting lighter weights for higher reps. The Journal of Applied Physiology study found that both groups increased their strength and muscle size by approximately the same amount, so if you’re relatively new to lifting or don’t feel up to hitting the heavy weights just yet, don’t worry; lighter lifts will still help you ditch the fat while gaining muscle tone.
A certain level of muscle strength is needed to function every day and do things such as walking and climbing stairs. Strengthening exercises increase this muscle strength by putting more strain on a muscle than it is normally accustomed to receiving. This increased load stimulates the growth of proteins inside each muscle cell that allow the muscle as a whole to contract.
Exercise has long been correlated with a longer life, but it’s only recently started to become clear why this might be. Studies, like a new one in the journal Preventive Medicine which found that exercise is linked to longer caps at the ends of chromosomes, have helped flesh this out a bit more. These caps, called telomeres, naturally shorten as we age, with each cell division. People who live a long time have telomeres that are in better shape than those who don’t—but there’s a lot we can do to affect the rate at which they shorten over the years. The team behind the new study looked at data from CDC's National Health and Nutrition Examination Survey, and found that for people who exercised regularly, their telomeres were 140 base pairs longer on average than sedentary people's. Which correlates to being years “younger” than their sedentary peers.