What Happens to Your Body When You Don’t Exercise Enough

Not exercising enough can have numerous side effects on the body, including weight gain, lower energy levels, and an increased risk of health conditions and diseases.

1. You Get Stiff Joints

You may notice stiff joints or decreased flexibility if you don’t move your body often enough. Regular physical activity enhances mobility, making daily tasks easier to accomplish. It also improves your range of motion, which can decrease pain and reduce your risk of injury.

2. You Experience Weight Gain

Not exercising enough can lead to weight gain—especially if you consume more calories than you burn in a day.

Exercising regularly (at least 150 minutes of moderate-intensity exercise weekly) and eating a healthy diet contribute to weight management, but are not the only factors to consider. Metabolism, underlying health conditions, and certain medications all play a role in managing your weight.

3. You May Notice Weaker Muscles

When you don’t exercise regularly, your muscles may get weaker and atrophy or “shrink.” Muscle weakness affects many people who have sedentary jobs, such as those who spend their days at a computer, making physical activity even more crucial.

Around the age of 30, adults begin to lose three to five percent of their muscle mass every decade as a natural consequence of aging. Healthy adults should aim to do strengthening exercises that target all major muscle groups at least twice a week.

4. Your Bone Density Decreases

Exercise is key for maintaining strong bones—especially as you age. Not exercising enough can contribute to bone loss. Over time, bones can become so weak that they break easily, leading to serious injuries.

Weight-bearing exercises build stronger bones. You can do these exercises in a standing position—such as walking, jogging, racket sports, and stair climbing—pressure on the bones is what causes them to build more tissue.

5. It Takes You Longer to Recover After Illness

People who exercise regularly often recover more quickly after illnesses such as COVID-19, pneumonia, and the flu. Exercise also boosts the immune system and can help prevent illness.

6. Your Stress Levels Increase

Not exercising enough can have adverse effects on your mental health. Research shows that exercise can help reduce symptoms of depression and anxiety.

You can feel the mental health effects of exercise immediately after a workout. Physical activity releases “feel-good” chemicals in the brain and also reduces cortisol levels in the body (a hormone associated with stress).

7. You Have Less Energy and Poor Sleep

Exercising regularly strengthens your heart and lungs. Over time, these organs become more efficient at delivering oxygen to your muscles, which means you’ll have more energy to do your daily tasks.

Exercise can also improve your sleep—it can help you fall asleep faster and improve the quality of your sleep. However, exercising too close to bedtime can have the opposite effect. Physical activity releases endorphins, which are hormones that help you feel more alert and energized. It also increases your body temperature, which also contributes to feeling awake.

8. You’re At an Increased Risk of Falls

Physical activity is essential for maintaining and improving balance, particularly as you age. Falls often lead to serious injuries, such as broken bones, head injuries, wounds, and even death.

9. Your Chronic Disease Risk Increases

People who live a sedentary lifestyle have a higher risk of developing chronic diseases, such as:

• Type 2 diabetes
• Metabolic syndrome
• Heart disease
• Stroke
• High blood pressure
• High cholesterol

Regularly exercising can reduce your risk of certain cancers, including:

• Bladder
• Breast
• Colon
• Endometrium (lining in the uterus)
• Esophagus
• Kidney
• Lung
• Stomach

How to Start Exercising

If you’re new to exercise, take it slow; start by taking short walks at a pace where you can carry on a conversation without losing your breath. Consider trying a group exercise class or working with a personal trainer for additional guidance.

If you have underlying health conditions or injuries, consult your healthcare provider to ensure exercise is safe for you. See a physical therapist for an individualized exercise plan.