Exercise on a Molecular Level

Dr. Laurie Goodyear studies the effects of exercise at the molecular level at Joslin.
Dr. Laurie Goodyear studies the effects of exercise at the molecular level at Joslin.

This article was first posted on May 31, 2013.

We all know exercise is good for us. Running, biking, weight lifting, or yoga—moving our bodies makes us healthier. And research at Joslin is clarifying why. The lab of Laurie Goodyear, Ph.D. studies what exercise does to our bodies on the molecular level, both after one exercise session and after making exercise a routine part of life.

When you exercise aerobically once—take one run, say, or swim 50 laps—your body experiences immediate benefits. This single bout of exercise, or acute exercise as it’s referred to in Dr. Goodyear’s lab, increases the amount of fuel your muscles need to keep working. And that fuel usually comes in the form of blood glucose, helping to clear the bloodstream of excess sugar.

Muscle is home to proteins called glucose transporters. They function as their name suggests—transporting glucose from the blood stream into the muscle. They usually live deep inside the muscle cells, but exercise turns on signals in the cells that call the transporters to the surface, allowing them to take up all the glucose muscles need to keep powering through the workout.

Benefits extend post-acute exercise, too. “Insulin works a lot better after exercise,” said Dr. Goodyear. “You can more readily take up blood sugar into your tissues.” The effect can last up to 24 hours after exercise.

“You don’t have to be highly trained for these responses to occur,” said Dr. Goodyear. Any form of exercise, even walking, helps; however, the more intense the exercise session the more benefit your body gets.

Studies have mostly focused on these acute exercise effects in aerobic exercise (the movement of large muscles and muscle groups that get your heart beating fast). Acute strength training also seems to provide these benefits, though the effects have not been as thoroughly studied.

Chronic exercise is exercise happening on a regular basis, or at least three sessions per week. People getting the recommended amount of physical activity each week, for example, are chronic exercisers.

If acute exercise has good benefits, chronic exercise is even better because you reap the short- and long-term effects. Routine cardio can actually change the amount of certain proteins in your body—including those glucose transporters that get activated with each single bout of exercise. The more glucose transporters you have, the more efficiently your body takes up glucose from the bloodstream.

And it’s not just muscle tissue that sees benefits. Almost all tissues in your body are modified for the better when you make exercise a regular part of your life—everything from your heart, pancreas, blood vessels, and even your body’s fat.

Strength training includes doing exercises using free weights, resistance bands, or even just your own body weight (think push-ups or squats)

Chronic strength training is “just as important to overall health,” said Dr. Goodyear. Working your muscles against resistance like bands, machines,  or free weights maintains muscle and bone mass. The more muscle mass you have, the more glucose gets taken up.

Also, “muscle utilizes more energy even in a resting state” than fat,” said Dr. Goodyear. So more muscle mass can mean a higher basal metabolic rate, which translates to more calories burned even when you’re just sitting around.

“Exercise is critical for everyone, but especially for those with diabetes,” said Dr. Goodyear. Given the increasing awareness that there is a link between Type 2 diabetes and cancer and cognitive function, including Alzheimer’s, it is especially important to mitigate the effects of diabetes by exercising. In fact, there is now strong evidence that there are lower rates of certain forms of cancers and Alzheimer’s in people who regularly exercise.

And if you aren’t losing weight, don’t quit! The molecular benefits of exercise are independent of weight loss. Studies have shown that people with high BMIs and a high percentage of body fat have a much lower risk of disease if they’re physically fit.

Physical fitness doesn’t necessarily mean trim and toned. It’s a measure of your body’s ability to take up oxygen; in other words how long you can perform an aerobic exercise. The more oxygen your body uses during a single bout of exercise, the harder you’re working, and the more physically fit you are.

If you can lose weight while you exercise, all the better, but “physical fitness is the strongest determinant of overall health,” said Dr. Goodyear. So get up, get out, and get moving!


  1. Would the effects be the same or similar if you are exercising using sitting exercises?
    I have arthritis in my knees so little or no impact exercises will be more benefial for me.
    I am learning to hula hoop again so would that play into this?

  2. The benefits of exercise are not restricted to people who have full mobility. In fact, if injury, disability, illness, or weight problems have limited your mobility, it’s even more important to experience the mood-boosting effects of exercise. Exercise can ease depression, relieve stress and anxiety, enhance self-esteem, and improve your whole outlook on life.
    If you have a disability, severe weight problem, chronic breathing condition, diabetes, arthritis, or other ongoing illness you may think that your health problems make it impossible for you to exercise effectively, if at all. Or perhaps you’ve become frail with age and are worried about falling or injuring yourself if you try to exercise. The truth is, regardless of your age, current physical condition, and whether you’ve exercised in the past or not, there are plenty of ways to overcome your mobility issues and reap the physical, mental, and emotional rewards of exercise.
    ◾Cardiovascular exercises that raise your heart rate and increase your endurance. These can include walking, running, cycling, dancing, tennis, swimming, water aerobics, or “aquajogging”. Many people with mobility issues find exercising in water especially beneficial as it supports the body and reduces the risk of muscle or joint discomfort. Even if you’re confined to a chair or wheelchair, it’s still possible to perform cardiovascular exercise.
    ◾Strength training exercises involve using weights or other resistance to build muscle and bone mass, improve balance, and prevent falls. If you have limited mobility in your legs, your focus will be on upper body strength training. Similarly, if you have a shoulder injury, for example, your focus will be more on strength training your legs and abs.
    ◾Flexibility exercises help enhance your range of motion, prevent injury, and reduce pain and stiffness. These may include stretching exercises and yoga. Even if you have limited mobility in your legs, for example, you may still benefit from stretches and flexibility exercises to prevent or delay further muscle atrophy.

  3. Dr. Goodyear and Team,

    I have had T1D since 1968 and continue to defy the odds preached in the 1960s. I love your term ‘Chronic Exercise’ and all of it’s related components. I began many forms of chronic exercising in 1957 including dance and acrobatics; in 1964, I began chronic weight training and continued for 50 years. In 1996 I began to study martial arts and kickboxing for 10 years. At age 61, I was bench pressing 375 pounds; and at 63, I suspect I am one of the healthier people out here and I continue exercising with passion!!

    The lessons you’ve learned and those you continue to learn should be part of the mandatory curriculum in nursing and medical schools. In the last five decades I have never heard so many health care professionals criticize high levels of exercise for diabetics. I suggest they should encourage more exercise and learning/training rather than stick with the suggestions that diabetics should back-off and settle down. Put exercise at the forefront and don’t make it a footnote.

    I live by what you have studied. Exercise as often as possible and never stop moving.

    Keep up the fantastic work!!
    Larry Hughes

  4. Like LH — Type 1 for 48 years, my experience confirms benefits of high intensity interval training (HIIT). I’ve been a chronic exerciser for 20 years — 5 days a week (HIIT on bike, weight training & stretching) for one hour daily. I maintain my A1c levels at 5.7.
    I agree that mobility isn’t a big issue & shouldn’t prevent diabetics from exercising. I also have cerebral palsy (CP) since birth or 68 years but keep working out. One needs to find ways to overcome such challenges.
    Thanks Dr. Goodyear for explaining this on molecular level!

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