When it comes to the benefits of physical activity, the list stretches from A (for attitude improvement) to Zzzz (for better sleep). Unfortunately, only 25% of U.S. adults get the recommended minimum of 150 minutes of aerobics and two strength-building sessions weekly.

But almost 40% say they're getting enough physical activity.

To help you accurately determine if you're activity-deprived, here are three signs that show you need to get moving:

1. You're feeling blue. Being sedentary increases depression. According to a 2019 study, if you replace 15 minutes of sitting with 15 minutes of running or an hour of brisk walking, you can decrease your risk of depression by 26%.

2. You can't fall asleep easily. According to Johns Hopkins Medicine, lack of activity makes it difficult to fall asleep and enjoy good quality sleep. But 30 minutes of moderate aerobic exercise can give you better sleep that same day.

3. Your joints are achy. Knees gotta bend, hips gotta extend. But many people are sitting five-plus hours and are sedentary for almost 10 hours every day. Gentle stretching and activities that move joints through their full range of motion improve flexibility and relieve discomfort. The initial twinges you might feel when beginning to exercise will fade, and you'll become more agile and have fewer aches and pains.

The reward is increased healthy longevity — about nine years for women; eight for men.