Dispelling Myths About Exercise The list of myths about exercise is long, and it can be difficult to reconcile new research with conventional wisdom. Dr. Timothy Church and celebrity trainer Mark Jenkins talk about what works when it comes to exercise, and the strategies people use to stay motivated.

Dispelling Myths About Exercise

Dispelling Myths About Exercise

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The list of myths about exercise is long, and it can be difficult to reconcile new research with conventional wisdom. Dr. Timothy Church and celebrity trainer Mark Jenkins talk about what works when it comes to exercise, and the strategies people use to stay motivated.

This is TALK OF THE NATION. I'm Lynn Neary in Washington.

When it comes to exercise, we know it's good for us, or do we? You've all probably gotten lots of advice from family, friends and the media. Sweating means you're losing weight. Crunches will get rid of your belly fat. You can eat anything you want as long as you work out. We all want to believe that last one, don't we? Today, we'll try to separate the truth from the myths about exercising and what we really need to do to stay fit and to get ourselves motivated. Later in the show, what the slow start to the Atlantic hurricane season means. And we remember guitarist and innovator Les Paul.

But first, exercise. What's worked for you? Have you been able to stay motivated? How? And if not, why not? Our number here in Washington is 800-989-8255. And the email address is talk@npr.org. You can join the conversation at our Web site, go to npr.org, and click on TALK OF THE NATION.

Dr. Timothy Church joins us now from member station WRKF in Baton Rouge. He is a physician and researcher and he holds a chair in health wisdom at Pennington Biomedical Research Center in Baton Rouge. Welcome back to the program, Doctor.

Dr. TIMOTHY CHURCH (Pennington Biomedical Research Center): Oh, thank you very much.

NEARY: So what is the biggest misconception that people have about exercise?

Dr. CHURCH: You know, I think there's obviously a few, but to me the biggest is, I don't think most people appreciate how many things it's good for. I don't think most people appreciate that, well, if you're physically active, you lower your risk of dementia. You lower your risk of certain cancers. You lower your risk of anxiety and depression. And of course the big ones we all know about, you know, heart disease, stroke and other things similar. But to me, the most important element of exercise is healthy aging. I mean, modern medicine is going to get most of us to the age we're supposed to get to, but there's no pill for healthy aging. There's no pill that assures that you'll be able to play with your grandkids or go duck hunting when you want to go duck hunting or get up and down stairs safely.

And there is one strategy which we know, which works great for aging, and that is being physically active and maintaining physical activity throughout a lifetime.

NEARY: But what do you think people get wrong about exercise? Even as they're heading into it, they decide they want to get in shape regardless of age - is there something that people do wrong as they're heading into an exercise regime?

Dr. CHURCH: Sure, I'll give you two. The first one is most people overestimate how much they need. For healthy aging, for general health, the goal is simple. It's 30 minutes a day, five days a week of walking. A 150 minutes of moderate intensity physical activity. These are not over the top goals. You don't have to train for a marathon to benefit from exercise. If you like training for marathons, that's great. Keep doing it. But you don't need to do that for general health. Thirty minutes a day, five days a week is a great goal. If you like to do things a little bit more intense, like jog - well, guess what? All you need to do is 75 minutes a week. So a lot of people will have this misperception if they're not doing mammoth amounts of exercise, they're not benefiting.

And then the other side is the one that everybody loves to talk about, of course, is exercise and weight. And there are so many misperceptions related to exercise and weight. And when you talk about weight, you can't talk about weight and just exercise. You can't talk about weight and just diet. If you want to lose weight or if you want to maintain a weight, you have to both be physically active and have a healthy diet, have a diet that - it's focused on moderation.

NEARY: Yeah, I think that's the big thing. People tend to feel that they can do one without the other sometimes. That you can - you actually can lose weight without exercise, can't you? But…

Dr. CHURCH: Well, this is an interesting thing. Is it - you can lose weight doing anything. Weight comes off really easy. The challenge is keeping weight off, keeping weight off at six months, at 12 months, at 18 months, and we know that people who lose a lot of weight and keep it off for a long time, they're physically active. Firstly, a hundred percent of individuals who've lost a lot of weight and kept it off for a long time are regular exercisers. And we're not really sure why, but we know it works. So, you can lose weight through a variety of reasons. But if you want to keep that weight off, you're going to have to be physically active.

NEARY: And there's probably some people out there saying you can take weight off easily. I don't know about that, but…

(Soundbite of laughter)

NEARY: I wanted to go back for a second to what you said about the 30 minutes a day, five minutes a day - five - five - 30 minutes a day, five days a week walking, because right there, I think, you know, there are some misconceptions, some - maybe some myths, because how fast do you have to walk for that to be effective? Can you just go out and stroll with your dog for 30 minutes a day?

Dr. CHURCH: Oh, absolutely.

NEARY: Yeah?

Dr. CHURCH: We keep saying the word exercise and what we should be saying is physical activity. This is really about leading a physically active lifestyle. And you can be very physically active yet never step into a gym or buy a pair of running shoes, you know. It's just about - you know, at lunch, walking to the deli instead of driving to deli. If you…

NEARY: See, because I did have the impression that there has to be - that the exercise has to be at a certain level for it to really be effective.

Dr. CHURCH: No. It really doesn't. It's really about just getting off the couch and not being a couch potato. Any activity has benefits, and what's really interesting, once again, and a lot of people don't appreciate is that people who are sedentary or people who have diabetes or high blood pressure or high cholesterol, they are really the ones to stand a benefit in a relative sense the most from any physical activity. So a lot of the health benefits that come from being physically active come from kind of just doing anything. And then the more you do, you have benefits more, but the pay-off, the return on investment is greatest from when the individual goes from being a couch potato to a regular walker.

NEARY: All right. Let me ask you about something else that I think you hear a lot when you begin a weight loss program. Sometimes they'll say, well, if you're exercising, you might not see as much weight loss in terms of pounds right away because, you know, because you're going to be turning your fat into muscle and muscle weighs more than pounds and therefore you may not see in pounds, but it doesn't mean that you're not trimming your body down. Is that true? Is all that true?

Dr. CHURCH: Total fiction.

(Soundbite of laughter)

Dr. CHURCH: Fat doesn't turn into muscle. Muscle doesn't turn into fat. And if you're physically active, when it comes to weight loss, it's really simple thermodynamics. The more calories you expend or the more calories you burn every day compared to how many calories you take in, the more successful you'll be with weight. There's 3,500 calories in a pound - once again, 3,500 calories in one pound of human tissue. So if you every day have a 500 calorie - you expend 500 calories more than you take in, after a week you have lost a pound. If you're being physically active, you're burning more calories.

The more calories you burn, the quicker the weight loss will be. Now, at the beginning of a weight loss program, clearly it's easier to cut 500 calories out of your diet than it is to exercise for 500 calories a day. So in the beginning of weight loss, it's an easy argument to make that, well, focusing on the diet is more efficient for producing weight loss as opposed to exercise. But as we already talked about, exercise is critical because in the long term you're simply not going to keep that weight off unless you're physically active.

NEARY: All right. Let's take a call now from John, who's calling from Pleasanton, California. Hi, John.

JOHN (Caller): Hi. How's it going?

NEARY: Good, good. Thanks.

JOHN: I just wanted to say that as - both as an engineering student and somebody who used to weight nearly 300 pounds - I'm actually very healthy now -diet control is, as the commentator said, is the crucial part of losing weight. Exercise helps insofar as it increases lean body mass, which increases the amount of energy you use at rest. You see, your body is a heat engine in order to maintain all the processes of life, and the amount of energy used to generate heat is a heck of a lot more than used to generate motion.

Like, for instance, the amount of calories in a doughnut will accelerate an SUV to 60 miles an hour. So really, exercise as burning calories in and of itself really isn't useful for, you know, losing weight. That's really all I needed to say.

NEARY: All right, and Dr. Church, do you agree with that?

Dr. CHURCH: Unfortunately, he's an engineer and not a physiologist, and he just addressed a common myth, and that's the idea that exercise builds up a whole bunch of lean mass, and that lean mass burns calories the rest of the day, and it really doesn't.

When you lose weight, when you lose a lot of weight, you're losing fat and muscle, and as you lose weight, your metabolism goes down because your metabolism is strictly driven by your body mass. The bigger you are, the larger your metabolism. As you lose weight, you're getting smaller, your mass gets smaller - therefore your metabolism goes down.

That's a common myth around exercise for most people, unless you're doing extreme training. Your muscle is - first of all, you're not building up muscle, and second of all, your muscle doesn't burn more calories when you're not exercising. This mythical after-burn that we all loved to talk about 10 years ago, we've kind of learned, we've come to learn it's largely - there is no such thing as after-burn.

NEARY: All right, let's take a call from Lisa calling from Boston. Hi, Lisa.

LISA (Caller): Hi. I'm calling because I wanted to make the point - I'm quite a large person, well over 300 pounds. I regularly exercise, at least five days a week. I work with a personal trainer. I'm now into kettlebells, which I just love, and I want to make the point: After years of not exercising, what got me started and going is understanding that it's really not about the weight, that you can be healthy and happy and fit no matter what the size you are if you're willing to get out there and exercise.

All my numbers, except for that number on the scale, all my other numbers are in great shape, are in a great range. I have great stamina. It's not the size of your body, it's what you do with your body that counts, and I think focusing on the weight really frustrates people and gets them stuck. Because anybody can lose weight. It's keeping weight off that 95 to 98 percent of us just can't do, and all the studies show that.

NEARY: Dr. Church, that's interesting, because here this listener is saying - I think she said she weighs 300 pounds, which is…

LISA: I weigh 350.

NEARY: Okay, she weighs 350. And how tall are you?

LISA: I'm 5'8".

NEARY: Okay, that's - I mean by most standards…

LISA: I'm a big woman.

(Soundbite of laughter)

LISA: I'm fat, there's no question about it, but I also have a lot of strength, a lot of stamina. My blood pressure's great. My blood sugar's great. My liver function's great. I'm very healthy because I work out and I eat well. It doesn't really matter what the size of your body is, and focusing on the weight loss is such a waste of time.

NEARY: All right, well, thanks so much for your call because it's a great perspective to hear from. And I think we're going to have to wait, Dr. Church. I want to hear your response to that listener's call, but we have to take a short break now, and then we'll be back.

We're talking about exercise and some of the myths floating around. Give us a call at 800-989-8255. We want to know how anyone stays motivated. What works for you? And you can also send an email to us at talk@npr.org. We're going to have a personal fitness trainer with us when we return. I'm Lynn Neary. It's TALK OF THE NATION from NPR News.

(Soundbite of music)

NEARY: This is TALK OF THE NATION. I'm Lynn Neary in Washington. We are dispelling some of the myths about exercise today, but it's one thing to know the facts and another thing entirely to actually push yourself to work out on a regular basis. So a personal trainer will be joining us in a moment to help us with the motivation part of the equation.

What's worked for you? Have you been able to stay motivated. How, or why not? The number again: 800-989-8255. And it counts as an aerobic exercise to type out an email - well, I like to think that, anyway.

The address is talk@npr.org, and Dr. Timothy Church is still with us. He's a physician and researcher and expert on exercise and health. And Dr. Church, just before the break, we heard a listener call in, a woman who weighed, I think she said 350 pounds but exercises every day, and apart from her weight, all her other numbers indicate she is a very healthy person. I'd just love to hear you respond to that call, Dr. Church.

Dr. CHURCH: Oh, good for her. I mean, there's such a great lesson there, and that lesson is, you know, as we talked about, exercise benefits everybody from a health perspective, and it benefits people of every weight.

We've shown that time again in our research. You know, we've shown it in individuals who were overweight or even technically obese, actually, who were regularly physically active, have about the same health risks as a normal-weight individual, and actually - or lower health risks than normal individuals who are sedentary.

So I think there's a great, great point there, and that is, you know, people at every weight stand to benefit from being physically active…

NEARY: Let me just ask you - let me just ask you one follow-up to that because we hear so much about obesity and the problems associated with obesity. But if a person is physically fit, then - what, it offsets those problems of obesity?

Dr. CHURCH: Well, you know, you can't really generalize, and for things like diabetes, you know, weight is more important than physical activity, but physical activity is also a super-powerful risk factor.

You know, we have another epidemic in this country that no one's paying attention to, and that is physical inactivity. We are a very, very sedentary country, and activity is, I like to say, as powerful as a risk factor as smoking, yet we don't treat it like that. And yes, activity plays a role in weight, but we should kind of be talking about activity just for the sake of activity and the importance of activity or the benefits of activity and exercise exclusive of weight.

And I think that last caller was a great example. There are some people who are never going to be normal weight. They're just not going to.

NEARY: All right. Let's take another - bring another voice into this conversation now. Mark Jenkins is with me here in Studio 3A. He leads classes at the SomaFit Gym in Washington. He's also the author of the book "The Jump Off: 60 Days to a Hip-Hop Hard Body." Welcome to the program.

Mr. MARK JENKINS (Personal Trainer): Thank you for having me.

NEARY: So whether or not you are trying to lose weight, but you want to get started in exercise, how do you help people not just get started but get them motivated to keep with it?

Mr. JENKINS: Well, you try to figure out what each person - as a personal trainer, I think your job is to figure out what each person, how they function, whether it be a parent, a teacher or a businessman, and you try to teach them how training and being active in the fitness lifestyle enhances what they're doing other than the gym.

So it's not just a superficial pursuit. It's going to enhance you as a parent, a teacher, a citizen. So it's totally encompassing your whole life, because as soon as you go through any adversity, or people get stressed out, what do they do? They stop working out. They start eating.

So if you can quantify getting up earlier in the morning or staying up late at night to get that workout in or adhering to a diet or spending a little bit of money to get some nutritious food and show benefits other than just superficial, people are more apt to stay with it long-term.

NEARY: Yeah. I think probably a lot of people have the experience, certainly I have had the experience, of going through periods where I've been involved in exercise and then just, I don't know, falling off the wagon, and you know, when it happens, you almost - it can be a difficult - something can motivate it, but sometimes it's just slipping off the wagon.

Mr. JENKINS: Well, goals are very important: short-term goals, long-term goals, and challenging yourself and then taking that empowerment that you get from achieving that goal and transferring it to other areas of your life.

And I think the fitness community misses out when they present fitness and health and fitness to the general population. They're like, you just need to work out because it's the right thing to do as opposed to let me take you on a journey, and let me show you how this is going to benefit your life and that you can see some tangible benefits in income, just like the doc said.

Fitness affects so many other areas of your life other than just how you look. Just to be competitive in this society these days, you have to be mentally sharp, and your body houses your brain.

NEARY: So do you talk to people about the best kind of exercise for them or an exercise that they'd be more likely to stick with, or do you steer them in one direction, to one certain kind of exercise?

Mr. JENKINS: I usually - I try to explore with a person. Like, when I come on with a client, I'm their guide, and I expose them to different types and different methods of training. So I expose them to kettlebell. We might box. We might do mixed martial arts. We might be off in the range. I do mandatory one outside session every week just to get the person outdoors, so they're using their body in a functional manner, and I see what the person likes, and then I build a program based on their likes and dislikes and try to turn them on to an activity. So if they're training for an activity, they're more apt to stick with the training.

NEARY: All right. Let's go to a call now. We're going to take a call from Sara. She's calling from Corvallis, Oregon. Hi, Sara.

SARA (Caller): Hi. I'm calling because - I'm still walking because I'm exercising, and the things that your last commentator was saying are perfect. You have to have your big goal, and my big goal was to not end up in a wheelchair after I was diagnosed with metastatic cancer, bone cancer on my spine, and I have it from the cervical spine all the way to the pelvic and into my pelvic bones, and also on the ribs, but those are less difficult.

And I've maintained walking and mobility by doing Pilates exercises regularly, but I didn't start out with Pilates. I started out with Feldenkrais, which is a kind of therapeutic exercise program, and it's very gentle, and to my mind, the big thing that really torpedoed disabled people who are trying to stay exercising is that they start out doing something that's just too strenuous. And when I've tried to get counseling from a gym person, they always start me out at way too high a level, I mean really way too high a level, and then I can't sustain it. And then I end up feeling bad, and they - I feel guilty, they feel guilty. But the Feldenkrais and the Pilates are both intended to be done at your level of ability, and then you build strength, and…

NEARY: I just have one question. Did you - were you always someone that exercised, or did you start to get into exercise once you realized that you were ill and that you needed to exercise for this purpose?

SARA: Well, before I got cancer, I had another chronic illness, and that put me into bed for - I was bedridden or semi-bedridden for seven years, and I was not exercising. And then I discovered Feldenkrais to get me back, and then I worked into Pilates, and I've been doing Pilates for about 10 years.

NEARY: Wow, well, thank you so much for your call, and I want to just follow up on that. Thanks so much for your call. It's a totally interesting perspective. And Mark Jenkins, I'm wondering if you've worked with people who have had similar kinds of situations.

Mr. JENKINS: I've worked with terminally ill patients. I've worked with people who are partially paralyzed. I actually met a guy - I was using his piece of equipment on TV and he called me and he says, Do you know what this equipment is for? And I was like, no, I just thought it was a great tool. You know, I saw it on the Internet and I started using it. He said, I originally designed this for wheelchair patients who are incapacitated. That's why it's so easy to use and accessible for people.

So you know, no matter what condition you're in, there's always some type of activity that you can get into to enhance your conditioning. There's so many things out there, and you really have to experiment. Don't just give up if you hit a wall. Try to find out what works for you.

NEARY: All right, this is an email from Barb. I'm 54 years old, 5'4", 122 pounds, have had three children, and I've always been sedentary. I'm a computer nerd. I hate - in capitals - hate to exercise. Blood pressure low, no physical problems. I'm starting to stiffen up with age and would love to exercise. Can you help?

Mr. JENKINS: Certainly I can help. It's just a matter of, we'll start gradually. Someone like that, you start with walking. They don't like exercise, so you don't want to overwhelm them, and then talk about what the person is interested in and then you try to find the match.

You have to find out what works, and it takes a little bit of experimentation. So what I would say is, don't be afraid to go out there and just try something, because you'd be surprised. You may like it.

NEARY: All right. Here from Lisa(ph) in Ames, Iowa. She says: I like to do what I call random acts of fitness: taking the stairs, parking at the back of the lot, biking to the movie store, stretching and moving during normally sedentary activities like watching TV.

But here's the question: What if you really don't like doing any of this stuff? What if you really don't like moving, somebody that just is a couch potato, finds it hard to walk the three flights up the stairs. They know they should, but they don't, or doesn't really even like to go walk the dog. Have you got any advice for that kind of person?

Mr. JENKINS: I have several clients who hate working out, and they curse every minute, every second that we're actually training - like, I hate this, I hate this, I hate this. If that is the case for you, you have to realize the benefits and just push yourself through. You have to take that 15 minutes to a half hour that the doctor is necessary for you to train, and you just have to force yourself to do it and think about the benefits, and that's what I always tell you. Hey, it's only a half hour out of your day, think about the benefits.

NEARY: Dr. Church, you got any thoughts on that?

Dr. CHURCH: Yeah. You mean, you might hate being physically active but how much are you going to like a heart attack? Or how much are you going to like, you know, being physically disabled as you age? I mean, we're - our bodies are designed to be physically active. We know it doesn't take that much activity to get huge health benefits. If you are super sedentary and going to remain super sedentary, it will catch up with you. It's like the smoker who says, well, I feel great now, I don't - why should I quit smoking? It's going to catch up with you.

NEARY: Is it ever too late? I mean, is there ever a point at which you've been sedentary for too long and you cannot turn things around?


NEARY: No, really?

Dr. CHURCH: People of every age in a relative sense. Obviously, the person who's physically active their whole life is going to be in a better place later in life. But we've worked with 75 to 90-year-olds and, you know, who we do these walking programs with and these very mild weight lifting programs and they have huge benefits.

NEARY: All right. Let's take a call from Kenneth(ph) in St. Helena. Hi, Kenneth.

KENNETH (Caller): Hi.

NEARY: Go ahead.

KENNETH: Yeah, I just wanted to ask about just the best advice I can get on making a regular habit of three to five days a week of working out, whether it's getting to the gym or riding my bike or running or whatever it may be. I tend to work out maybe once a week and sometimes once a month and just get distracted by a million other things to do each day.

I also want to pass on a super quick comment that in the last hour, you know, discussion on health care, I was kind of disappointed that it seemed like you almost primarily just only offered the right wing Republican perspective on things. And unfortunately, I don't think that that's real healthy for the debate…

NEARY: Okay. You know, we're not talking about that now.


NEARY: And I thank you so much for calling in. But why don't you give some advice on exercise here.

Mr. JENKINS: Oh, you want me to go?

NEARY: Yeah.

Mr. JENKINS: Okay. Yeah. Exercise-wise, you have to schedule it in just like you schedule everything else you do. And you have to realize that that's - that you making that schedule is going to enhance everything else you're doing. You have to program your mind and really buy in to the fact that exercise is going to enhance everything you do. And it's a adjustment, but it's a lot of self-talk and self-programming. And you have to buy in to that. If you don't buy in to that, you won't say consistent with your workout program.

NEARY: All right. So, not just make the - not just put it on the schedule but you got to stick to that schedule.

Mr. JENKINS: But you have to understand…

(Soundbite of laughter)

Mr. JENKINS: Yeah, yeah. You have to realize that you making that workout is as important as you getting to work every day because that workout is going to empower you and is going to infect you to work - it's going to give you the ability to work more effectively and possibly make more money or take that confidence so you start your own business and get your own thing going. You have to look at it as an empowerment tool.

NEARY: Mark Jenkins is a trainer at SomaFit in Washington, D.C. And you are listening to TALK OF THE NATION from NPR News. We're going to go to Jeff(ph) in Boston. Hi, Jeff.

JEFF (Caller): Hi.

NEARY: Go ahead.

JEFF: I think the biggest thing that's helped me maintain a very active lifestyle is just - from a young age, you know, my parents insisted I be active. And now, I just, I really enjoy working out. And so I think that's the key. You have to find something that you really enjoy. And, like, for me, like I hate running, so I don't run. You know, and like, all my exercise I do, I do it with friends. So it's more, it's not a chore, it's something I look forward to in my day.

Mr. JENKINS: That's great, Jeff. Some people don't like one-on-one training. Some people prefer group classes. Some people prefer swimming. Some people prefer martial arts. Some people prefer, you know, just taking long walks with a nice iPod, man, with a good mix on there, and just walking and getting out there and being active.

JEFF: Exactly. I think that's the key is, you know, exposing yourself to many different sports and different things is finding something that you enjoy. And I think that's the easiest way to make exercise available to yourself.

NEARY: All right. Thanks so much. We're going to go now to John(ph) who's calling from San Jose, California. Hi, John.

JOHN (Caller): Yeah. I've swam over a thousand miles since early in 2005. And I swam two miles at a time, and I'm now 64 years old. And, boy, it's been saving my life.

NEARY: Why do you say it's been saving your life, now that you're 64?

JOHN: Well, I had a back operation and couldn't swim for a while. And my blood pressure was up to, like, 190 over 90.


JOHN: And then, if I get out of the pool now and check my blood pressure, it would probably be about 125 over 65 or something like that.

NEARY: Swimming a good exercise, Mark?

Mr. JENKINS: Swimming is one of the best exercises because not only do you get the resistance, you're working your cardiovascular system at the same time.

NEARY: Okay.

JOHN: You can swim any amount too. I mean, two lengths from pool, going from two lengths to four lengths is as hard as going from 20 to 40. Whatever level you are, you just incrementally increase it, and by then, you can do anything.

NEARY: All right. Well, thanks so much.

And, Dr. Church, I just wanted to read this e-mail from Peggy(ph) in Rio Vista, California. I'm 52 years old, I run five miles a day, four days a week, I go to the gym for one half and hour two days a week. And I'm 5'7" and weigh 120 pounds, and I have since high school. I'm a vegetarian now, and wonder if I'm too thin. If I'm getting enough of what I need to maintain this level of exercise and healthy fashion or, as my husband tells me, I am an exercise nut. Am I?

Dr. CHURCH: Well, she may be. But she sounds highly functional. That program certainly doesn't sound out of bounds. And if her weight has been this way for the last 50 years or, obviously, since she was, you know, let's say, last 30 or 40 years, in other words there's been no major fluctuations. It sounds like she's got a great program and needs to stick with it.

NEARY: Can you do too much? Is it ever possible to too much exercise?

Dr. CHURCH: This is a really loaded question. And…

NEARY: And I asked it right at the end.

(Soundbite of laughter)

Dr. CHURCH: …from a health perspective, there's not that much data to suggest that unless you're really, really extreme is there such a thing as too much exercise. Now, it may not be good for your relationships in your life, but one of the problems is with extreme exercisers, there's a lot of them who tend to have eating disorders. So, now, you got kind of a double whammy.

But from a cancer risk, from a cardiovascular risk, unless it's crazy extreme, like running 150 miles a week, there's really not much evidence to suggest that there is such a thing as too much exercise.

NEARY: And I would guess that…

Dr. CHURCH: And it's clearly not a national epidemic.

(Soundbite of laughter)

NEARY: Right. And I would guess, Mark Jenkins, you'd agree.

Mr. JENKINS: Yeah. It's very hard to do too much. It's very, very hard to do too much. I mean, something will tell you to slow down. Mentally, you'll get burned out before physically.

NEARY: All right. Well, thanks to both of you for being with us. Mark Jenkins joined us in Studio 3A. He's a trainer at the SomaFit Gym in Washington and author of the book "The Jump Off: 60 Days to a Hip-Hop Hard Body." And we also talked with Dr. Timothy Church. He's a physician, researcher and chair of Health Wisdom at Pennington Biomedical Research Center in Baton Rouge. Thanks to both of you for joining us.

And coming up, where are all the hurricanes? I'm Lynn Neary. It's TALK OF THE NATION from NPR News.

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