There's a clear connection between the way your brain thinks and the way your body feels. And just as you can use your body to reduce your psychological distress, you can use your mind to improve your body.

Simply changing the way you think and taking charge of what occupies your mind can improve your physical health and well-being. Positive thinking won't cure everything, but a healthy mindset is a key component to a healthy body. Here are seven ways you can use your mind to promote physical health:

1. Make your treatments more effective by expecting them to work.

Countless studies show the placebo effect influences the effectiveness of treatment. If someone tells you that a pill will cure your headache, you're more likely to find the treatment helpful—even if the pill was a sugar pill. Whether you're trying physical therapy for a bad knee or you're seeing a chiropractor for pain in your back, your belief that those treatments will work may be more effective than the treatment themselves. So before you undergo any kind of treatment, think about all the reasons the treatment is likely to help.

2. Sleep better by writing in a gratitude journal.

If you're struggling with insomnia, a gratitude journal might be the best cure. Several studies have linked gratitude to better quality and longer lasting sleep. Before you go to bed, identify three things you're grateful for and write them in a gratitude journal. Conjuring up feelings of thankfulness right before you fall asleep will increase the chances of you getting a good night's rest.

3. Live longer by focusing on your purpose in life.

Feeling like you have a sense of purpose could actually increase the length of your life. Studies consistently show that people who believe their lives are meaningful are more likely to live healthier, longer lives. Whether your work gives you a purpose or you find meaning by volunteering your time, make sure whatever you're doing matters. Feeling like you have a reason to get out of bed every day might be the secret to longevity.

4. Be optimistic and boost your immunity.

Several studies have shown that optimistic people are less likely to get sick. For decades, many researchers thought the boost in immunity stemmed from the fact that optimistic people were more likely to take care of their health. But more recent studies have shown that a hopeful outlook is actually what influences immunity. Looking on the bright side makes you less likely to get a cold or infection because optimism keeps your immune system performing at its peak.

5. Slow aging with meditation.

Meditation provides a generous buffer against the harmful effects stress can have on the body. Numerous studies have shown meditation slows the rate of cellular aging. Meditation can help you stay looking youthful, and it could help you ward off age-related disease. Researchers suspect teaching children to meditate could provide lifelong benefits. But no matter what age you are, it's never too late to gain some health benefits from meditation.

6. Build muscle by imagining yourself working out.

What if you could get buff by imagining yourself lifting weights? Well, researchers have found that mental imagery can help you gain muscle without lifting a finger. One study found that people who imagined themselves working out were able to gain 24 percent more muscle strength. People who actually lifted weights saw better results, but the research shows mental training can provide real changes to muscle mass.

7. Reduce your risk of heart disease by laughing.

If you want to build a healthier heart, think about something funny. Research shows laughter decreases stress hormones, increases "good" cholesterol, and reduces artery inflammation. Perhaps laughter really is the best medicine—the positive effects of laughter last 24 hours.

The Power of Your Mind

Your mind can be your best asset or your worst enemy. Learn how to train your brain to help your body perform at its peak. Everyone has the ability to build mental strength. With practice, mental exercises could be the key to living a longer, happier life.