What Happens When We Don’t Exercise?

Joe Cross hiking
By: Stacy Kennedy, MPH, RD, CSO, LDN; Reboot Nutritionist

“Use it or lose it,” is the motto when it comes to physical activity and health, especially as we age. We all know the drill: Without being physically active, our chances of chronic illness and burden of disease skyrockets, like heart disease, high blood pressure, increased risk of certain cancers, anxiety and depression. And the flip side is true as well; bumping up activity can help to significantly reduce these risks, especially in people who are overweight or obese.

Knowledge may be power but it doesn’t always translate to action. As many as 88% of Americans aren’t getting regular exercise, defined as 5 or more days per week for 30 minutes. So by exercise, we’re not talking about running marathons or hiking Everest; we’re talking about walking the dog for 30 minutes, playing catch with the grandkids, or playing golf.

What really happens to our bodies when we don’t exercise? Let’s take a deeper look at what can go wrong (feel free to get up and move while reading this list!!).

Bad to the bone

Think popping calcium supplements is the best way to preserve bone density and prevent osteoporosis? Think again! Consuming more calcium may not keep bones strong, according to Harvard School of Public Health.

What’s best for bone mass? Put down that glass of milk, grab your sneakers and get outside. Vitamin D and resistance exercise are crucial for caring for bones, especially with age.

Feeling blue

Lack of exercise doesn’t just compromise our physical health, but our mental wellness can suffer too. Prenatal yoga, for example, has been shown to offset anxiety and depression in expectant moms. And the concept of the “runner’s high” is real. Even walking in nature can relieve the blues.

No snooze, you lose

Sleep habits are now understood to be as important for health as your eating habits. Lack of exercise can compromise sleep, leading to a long list of risks including depression, weight gain, inflammation, higher stress levels and chronic diseases like heart disease and diabetes.

Dulling your mental blade

Staying sharp doesn’t just come from doing crossword puzzles, Sudoku or “brain games.” Regular physical activity is required for keeping our thinking, learning and judgment skills sharp with age.

And we all fall down

Balance and strength are required for staying on your feet.   Reduce your risk of falling with more activity; it’ll keep your bones and your balance stronger.

Time really does fly

One of the many problems with lack of activity is less longevity. In other words, the less active you are, sadly, the greater your chances of early or sooner death. Studies show that regular physical activity can help you live longer and cut your chances of early death significantly. Getting less than 30 minutes a week of exercise can accelerate risk of death, but by committing to 7 hours a week of activity you can cut your risk of dying early by 40%. If that sounds unrealistic or out of your current comfort zone, even 2.5 hours a week of moderate-intensity activity can make you more likely to be around in years to come.

Want to exercise but still have reservations?

Movement and exercise aren’t always the same thing: Moving, walking, stretching, just simply, well… getting up and moving your body is most important for health. Don’t feel you need to do a lengthy or super intense workout to get benefits. Research is consistent and clear; activity or simply moving is most valuable. The benefits of walking and movement are so vast—everything from promoting breast cancer survivorship to lowering blood sugar and diabetes risk or combating fatigue.

Getting up from your desk for 5 minutes every hour to take a quick walk around the building, to the bathroom or for more water can add up and help. Parking farther away, taking the stairs one or more flights, or walking the dog for an extra lap around the block, count towards your 30 minutes. Keep it simple and turn your errands into exercises.

We’ve developed the perfect, easy and just-right movement plan for you, the Reboot Movement Method.

What are your favorite physical activities? When do you fit them into your busy lifestyle? We’d love to hear from you!


Stacy Kennedy, MPH, RD, CSO, LDN; Reboot Nutritionist

Stacy is a Board Certified Specialist in Oncology Nutrition and an Integrative Nutritionist. She consults for various companies, focusing on health, wellness and innovative strategies to help increase individual’s fruit and vegetable intake. Stacy is an American College of Sports Medicine Certified Health Fitness Specialist; she holds a BS degree in Dietetics from Indiana University, completed her dietetic internship at Massachusetts General Hospital, and earned a Masters in Public Health from the University of North Carolina at Chapel Hill. She is a Senior Clinical Nutritionist at the Dana Farber Cancer Institute/Brigham & Women’s Hospital, Harvard Medical School teaching affiliates, in Boston, MA, with more than 20 years of experience. Stacy created and now serves as project manager and lead writer for nutrition services content on the Dana Farber website and the affiliated, nationally recognized nutrition app. Stacy is regularly featured on TV, radio, print and social media on behalf of Dana Farber and other organizations. Together with her husband, Dr. Russell Kennedy PsyD, they have a private practice, Wellness Guides, LLC. Stacy is an adjunct professor in Wellness and Health Coaching at William James College, currently teaching a graduate course in Health Coaching. Stacy is featured in the award winning documentary films, “Fat, Sick & Nearly Dead” and “Fat, Sick & Nearly Dead 2,” and serves on the Reboot with Joe Medical Advisory Board. Stacy lives in Wellesley with her husband, two sons and three dogs. She enjoys cooking, yoga, hiking and spending time with friends and family. Stacy is also one of the nutritionists who runs our Guided Reboot programs.

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