Harder does not mean better: Mariel's story
I got hard-wired to perform exercise at an incredibly high level when I trained for the role of an Olympic hopeful pentathlete in the film Personal Best at the age of 17. After experiencing track and field training like a professional athlete, the discipline and, perhaps more importantly, the addiction to that kind of adrenaline high, was firmly established in my body and strongly engraved in my brain. Pushing to the edge, every session, became the way that I looked at exercise. You really weren't doing anything unless you were doing a lot – or too much. It played into all of my competitive, perfectionist, and compulsive tendencies.

For the next 10 years, pushing my body to an extreme of strength and fitness, almost every single day, was my way of imposing order and control in a life where much felt unsettled: my career as a young actress, my feelings about my body and food, my fears about my family and its dark legacy. Hard exercise became a way to escape those fears. I'd run and train hard propelled by sheer willpower most of the time, not ever slowing down to a walk for fear that I'd not be able to run again.

An unhealthy addiction
In combination with my extreme low-fat, low-protein diets, my adrenaline-junkie habit weakened my resistance to illness. If there was even a slight change in the weather, like rain or a cold snap, I'd be fighting a sore throat and if I couldn't fight it with my natural remedies, it would take me down for the count. I would put myself in ridiculous, gigantic places. "If I did an hour and 25 minutes today, I'll do an hour and 30 tomorrow." And on and on so that by the end of the month I was doing a crazy amount, and then I'd get sick to recover. I went for years without giving myself a day off. Seven days a week, for two to three hours a day of hard work until my body would finally say, "You are such a jerk, I'm going to get sick so that you have to stop, because you won't slow down, and I can't keep up!" In fact I think my body was wise: a cold or flu was a last-chance way for it to rest because I was unwilling to listen and slow down of my own volition. It was my way of feeling in control, but that very need for control was controlling me. My sense of well-being and my health were always at risk. So who was really in control? Certainly not me. It seems obvious to me now, but it wasn't at the time. Body issues are about the desire to control something – anything! – in a life that is always changing. The irony is that you can't control anything, so why not give up trying to control your body? When you give up the compulsions, the body finds its natural place, the weight and comfort level that suits it best. The mind and its anxiety, as I found out, create more problems than any actual weight gain or loss does.

Page 1 of 2 – Discover the secrets to effective – not exhaustive – workouts on page 2.

Excerpted from Mariel Hemingway's Healthy Living from the Inside Out by Mariel Hemingway. Copyright 2007 by Mariel Hemingway. Excerpted with permission by HarperCollins. All rights reserved. No part of this excerpt may be reproduced without permission in writing from the publisher.

Finding the middle ground
Modern-day exercise habits tend to fall to extremes. The majority of people are either underexercisers or overexercisers, and neither side is accessing a moderate middle ground where exercise is truly helping them, not hindering them. There is a lot of misinformation out there. For one thing, it's been ingrained in us for years that more pain will equal more gain, and that simply by doing a harder, more exhausting workout, we will be more fit. That is not the case. Similarly, like fad diets and food trends, new exercise trends come along at a steady clip, always promising better and faster results. Exercise, the thing that is supposed to provide relief and fun, can sometimes seem like one more thing to keep up with. For the purpose of this program, you're going to slow down, tune out all those external messages for a few weeks, and tune in to a more reliable source of information: yourself.

There's a real danger in the more-is-more approach. Did you know that intense cardio activities actually cause stress on the body? They cause a catabolic reaction, meaning they destroy tissue. The body goes into alert-mode and urgently looks for energy. If it doesn't find it immediately from food, the energy will get drawn from the most easily available sources like muscles and organs (rather than the harder-to-get fat deposits). If your life already has its share of stress, including a mediocre diet and too little sleep, or if your health is compromised in any way to begin with, this new set of stresses will tip you way out of balance. Sickness and injury, as well as reduced endurance and lack of strength, will be far more likely. Overtraining can also trigger emotional responses like irritability, anxiety, and sensitivity to criticism (all things that you might, ironically, decide are causes or not working out enough). New mothers who take on hard exercise too quickly can develop postnatal depression.

If, on the other hand, you are nourished, rested and calm to begin with, the stress from intense cardio workouts might be easier to absorb and you might love them. But it's wise to be conscious that you may unwittingly be adding much more stress to your life by doing the very thing you're hoping will destress you. The endorphin rush that comes with high cardio can feel great, but did you realize it's also a sign that you have just pushed your body into emergency fight-or-flight mode? When you are in that state, all nonurgent bodily functions get shut down, like digestion and reproductive functions. That's why chronic overexercising can throw off the entire balance of your body.

Page 2 of 2 – Do you push yourself too hard? Find out why harder doesn't mean better when it comes to working out on page 1.

Excerpted from Mariel Hemingway's Healthy Living from the Inside Out by Mariel Hemingway. Copyright 2007 by Mariel Hemingway. Excerpted with permission by HarperCollins. All rights reserved. No part of this excerpt may be reproduced without permission in writing from the publisher.