Is exercise good for you? Duh. Regular workouts give you strength, energy, a trimmer body, a healthier heart, a calmer mind and a much lower risk of at least 35 (!) different devastating diseases, including high blood pressure, stroke, osteoporosis, nonalcoholic fatty liver disease, diverticulitis, Type 2 diabetes, colon and breast cancer and, yes, even that star of prime-time TV: erectile dysfunction.

In spite of what we know, we don’t do. According to the latest research, 92 percent of adolescents and 95 percent of adults in the U.S. do not meet the minimum guidelines for physical activity.

Oh, dear. When I think about the gap between what we know about the benefits of exercise versus how much we actually do, I get weak in the knees.

And then I remember this: There is a right way and a wrong way to approach exercise. Do it thoughtlessly, impatient for quick results, and you are setting yourself up to fail. Do it consciously, and your chances of lifelong success are greatly improved.

Here are some of the ways in which people sabotage their own fitness, and, yes, dear reader, I may be talking to you:

1. YOU AREN’T TRULY COMMITTED. 

Saying you want to get in shape is not enough. You’ve got to have a deep-down, nothing-will-stop-me commitment. Change will happen only when you are ready, and when you are – hallelujah! – not only will you be able to overcome every obstacle; you will actually enjoy the process.

2. YOU HAVE FAILED BEFORE.

Many people don’t understand that change is not linear. It’s often two steps forward, one step back. Exercise dropouts have failed before, and the fear of failing again often makes them quit. You can break this self-defeating cycle by taking fear of failure off the table. Know you can succeed, and you will succeed, if you are patient and persistent.

3. YOU PUNISH YOURSELF INSTEAD OF REWARDING YOURSELF. 

Negative self-talk will derail you. Listen to your inner voice. If it says you’re lazy, stupid, ate too much and can’t get to the gym today, tell it to take a hike. Start a new inner dialogue based on kindness and compassion for the healthier, happier person you want to be. Create positive affirmations, like “I am capable of change and growth,” and repeat them often.

4. YOU COMPARE YOURSELF TO OTHERS. 

Your best pal runs half-marathons and you struggle with a 10K. Wendy can cycle 40 miles and you can barely finish 20. So what? Jealousy and envy are counterproductive and will lead you astray. Run your own race at your own pace. If you see others who are stronger, more flexible, thinner or more athletic, be happy for them … smile … and return your focus to your own situation. Be grateful you have a situation.

5. YOU REFUSE TO KEEP A JOURNAL. 

This may sound like a homework assignment from your dreaded algebra teacher, but the truth is, keeping a journal is a great tool for staying on track. So try it. Just a few observations: what you did; how long you did it; how you felt. Once you have the exercise habit in place, you can stop with the journaling.

6. YOU EXPECT QUICK RESULTS. 

Impatience is a big problem for people just starting to exercise regularly. You expect immediate results, and when you don’t see them, you find a reason to quit. Outsmart yourself. Take it day by day. Find joy in just showing up. In time, all the benefits of regular exercise will come your way. It takes the time it takes.

7. YOU SEE YOURSELF AS THE VICTIM. 

Many exercise dropouts blame their failure on someone or something: I can’t take time away from my kids. My job is too demanding. I travel too much.

These are excuses created to test your true intention. When you take responsibility for your own health and wellness, you give up being a victim and start living the more active, balanced, joyful life you’ve always wanted.

The beauty of self-sabotage is, whatever you do, you can undo. No guilt, no shame, just a willingness to start where you are – this time with a new, improved attitude and greater understanding about what it takes to succeed.

And what does it take?

Marilynn Preston is a healthy lifestyle expert, well being coach and Emmy-winning producer. She is also the creator of Energy Express, the longest-running syndicated fitness column in the country. She has a website, marilynnpreston.com, and welcomes reader questions, which can be sent to MyEnergyExpress@aol.com.