Prime Time Replay:
Dr. Peter Snell
on Human Performance
MsgId: *breakthrough(1)
Date: Wed Sep 3 20:41:41 EDT 1997
From: moderator At: 152.163.194.9
Welcome to Breakthrough Medicine. I'm your moderator, Madeleine Lebwohl, and tonight I'll be speaking with Peter Snell about human performance during athletic events, as well as ways of motivating people to lead more active lives.This is going to be an in-studio interview with Dr. Snell. Nice to have you, Dr. Snell.
MsgId: *breakthrough(4)
Date: Wed Sep 3 20:56:57 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: Nice to be here.
MsgId: *breakthrough(5)
Date: Wed Sep 3 20:57:55 EDT 1997
From: moderator At: 152.163.194.9
If people want to enhance their physical performance during exercise, what could they do?
MsgId: *breakthrough(6)
Date: Wed Sep 3 20:59:31 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: Well, firstly, the question is very general, and we need to know what type of exercise that one is trying to improve. And one needs to analyze the task for the various components, such as muscle strength, endurance, skill, and factors such as that. Now, in a simple activity such as running or cycling, where endurance is often the most important physical characteristic, then the preparation is more straightforward.For these activities the important thing is to use the concept of specificity. What that means is we do as much training that is related to the demands of the event as possible. And that implies that one at first must be properly conditioned through relatively gentle, easy exercises so the muscles can handle some of the more demanding training later.
My interest in exercise physiology arose through an Olympic career in middle distance running, and as a middle distance runner it was necessary to do a lot of early training that wasn't necessarily at race pace. I did a lot of running at six to seven minutes per mile, in the process of training to run a mile in under four minutes. Eventually, this large volume of easy running allowed me to do more running at race pace than otherwise would have been possible. For example, milers do a lot of repeat runs over short distances, such as 200 to 400 meters with a short rest between, and this running is done at close to or better than race pace.
MsgId: *breakthrough(10)
Date: Wed Sep 3 21:07:03 EDT 1997
From: moderator At: 152.163.194.9
How is this training preparing you physiologically?
MsgId: *breakthrough(11)
Date: Wed Sep 3 21:08:49 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: The physiological changes that allow such high level performance involves the improvement in the capacity of the heart to circulate blood -- and oxygen -- and the ability of the muscles to extract oxygen and use it to produce energy. So they're the two main systems that are being improved with this sort of training.
MsgId: *breakthrough(12)
Date: Wed Sep 3 21:09:45 EDT 1997
From: moderator At: 152.163.194.9
Has any research been done on ways to improve a runner's preparation?
MsgId: *breakthrough(13)
Date: Wed Sep 3 21:12:16 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: A lot of research has been done to compare the effectiveness of long slow running versus faster interval running. However, the most compelling evidence is from the actual experiences of athletes who tend to do the different types of training. And in general, it has been well established that a good base of slower running allows the athlete to handle more of the intensive race-related training and races down the line. Runners who do just racing or high intensity training tend to develop a state which is known as overtraining. And this is characterized by poorer performances. Unfortunately, a lot of coaches in high school tend to use this method because the results are faster. But the athletes suffer because they tend to not be able not to be able to hold their peak form.
MsgId: *breakthrough(16)
Date: Wed Sep 3 21:16:18 EDT 1997
From: moderator At: 152.163.194.9
Did you have personal methods for staying in peak form?
MsgId: *breakthrough(17)
Date: Wed Sep 3 21:18:06 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: To be careful in not racing too much; once a week for example is sometimes too much. And it depends on the length of the race. For instance, a marathon runner probably shouldn't run more than 2 marathons a year. So the shorter the race, obviously the more racing you can get away with without having adverse affects.
MsgId: *breakthrough(18)
Date: Wed Sep 3 21:18:38 EDT 1997
From: moderator At: 152.163.194.9
How do you recover if you over do it?
MsgId: *breakthrough(19)
Date: Wed Sep 3 21:19:55 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: Athletes who feel their performance is declining will often train harder. However, in this situation, the correct procedure is to train easier. Just go for an easy jog.
MsgId: *breakthrough(20)
Date: Wed Sep 3 21:20:27 EDT 1997
From: moderator At: 152.163.194.9
What happens to your body when you overdo it?
MsgId: *breakthrough(21)
Date: Wed Sep 3 21:22:44 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: Exhausting effort produces a degree of muscle damage. This is quite normal and the body repairs itself during recovery. There are hormones that are involved in the process of breaking down tissue, and others involved in building tissue up, and with too much racing there is an imbalance between the damage and repair process.
MsgId: *breakthrough(22)
Date: Wed Sep 3 21:24:03 EDT 1997
From: moderator At: 152.163.194.9
Are there any medications that can help speed up the recovery process?
MsgId: *breakthrough(23)
Date: Wed Sep 3 21:25:30 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: Anti-inflammatories are useful. However, techniques such as massage and anything that increases muscle blood flow is effective, such as easy jogging.The popularity of steriods (which are illegal) is due to their effectiveness in allowing athletes to tolerate harder training.
MsgId: *breakthrough(25)
Date: Wed Sep 3 21:27:49 EDT 1997
From: moderator At: 152.163.194.9
How can a average person, not training for an Olympic event, go about training to increase their health?
MsgId: *breakthrough(26)
Date: Wed Sep 3 21:30:00 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: There is an important distinction between training to improve physical fitness, and exercise that improves health. In order to improve fitness, the training needs to progress to moderately hard levels, however, moderate exercise, such as a brisk walk of 3 to 4 miles an hour, has a number of important health benefits.Some of the key benefits from exercise include an improved lipid profile, especially the lowering of plasma triglyceride levels. Secondly, an increased sensitivity to insulin -- this is very important for avoiding adult onset diabetes. Most studies on weight control that a combination of diet and exercise is much more effective than either alone. The relationship between obesity and premature mortality dissapears when one considers whether or not the overweight person is doing regular exercise.
Additional improvements involve the cardiovascular system. The pumping capacity of the heart improves, and recently it has been shown that the heart in a person regularly exercising is more resistant to arrhythmias. One of my research interests is in investigating the effects of exercise on improving the blood flow to muscle.
MsgId: *breakthrough(29)
Date: Wed Sep 3 21:40:05 EDT 1997
From: moderator At: 152.163.194.9
I understand you are currently working on how to motivate people to exercise more. Do you have any suggestions for us?
MsgId: *breakthrough(30)
Date: Wed Sep 3 21:42:53 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: In Dallas, we are part of a nation-wide study that is looking at ways in which sedentary people can be encouraged to increase their level of moderate physical activity -- their daily physical activity -- for a period of two years. This is proving to be very challenging. The motivation to exercise is not strong while an individual feels healthy. So if people are not being challenged by physical activities then they may never realize the tremendous decline in their physical ability.Its very difficult for most people to exercise for health benefits unless they actually feel better as a result of doing the exercise. One useful technique is to select an activity that you enjoy and that is maybe involves a challenging event. For example, Oprah Winfrey was motivated to train because she was planning a hike down the Grand Canyon. Many people are motivated to get themselves fit in order to go skiing. In the case of my wife and myself, we have an interest in the sport of orienteering. And this gives us the incentive to exercise regularly so we can participate in this activity.
I'm often asked what is the best exercise to do, and the answer is: The exercise that you enjoy and will do. And as long as it provides this moderate intensity that's important for health.
MsgId: *breakthrough(34)
Date: Wed Sep 3 21:51:12 EDT 1997
From: moderator At: 152.163.194.9
If you have been very sedentary, is there any point where you've damaged your health in ways that can't be easily repaired?
MsgId: *breakthrough(35)
Date: Wed Sep 3 21:54:33 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: We're still learning about this. For example, a big problem in older age is the loss of calcium from bone. Once you've lost calcium from bone its rather difficult to get it back. However, researchers at Tufts University have shown that muscles that have been neglected for years can adapt to training with impressive results in people as old as 90 years of age. The reason that trying to change sedentary lifestyles is a public health issue is because we are having an increasingly elderly population who are unable to look after themselves. So the goal of an exercise program is so that an individual can maintain their functional capacity, their ability to just do normal daily things well into old age. The important thing is to maintain physical independence.
MsgId: *breakthrough(37)
Date: Wed Sep 3 21:57:59 EDT 1997
From: moderator At: 152.163.194.9
Is one group in the general population harder to motivate for exercise than another?
MsgId: *breakthrough(38)
Date: Wed Sep 3 21:59:36 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: In general, people who are struggling to make ends meet find it difficult to find time to exercise. And as people get older and develop arthritis and various aches and pains they tend to think exercise is going to make things, whereas the opposite is true. And so we have the conditions for a downward spiral. The development of aches and pains which cause people to become inactive and actually causes the condition to become worse. In urban areas there are safety issues as well. One promising trend is the move to make areas safe for cycling by providing cycle paths and this sort of thing.
MsgId: *breakthrough(41)
Date: Wed Sep 3 22:02:41 EDT 1997
From: moderator At: 152.163.194.9
Do you have any hope that people will exercise more?
MsgId: *breakthrough(42)
Date: Wed Sep 3 22:04:55 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: I feel optimistic. Its taken quite a long time to reduce the number of people who are smoking, and in a way that's eliminating a negative habit. The exercise situation is encouraging a positive habit. Once people were clear about how bad for your health smoking was, it gave them a reason to quit. And likewise, as more and more evidence is gathered on the benefits of exercise, or the consequences of not exercising, that will also lead to fewer couch potatoes. However its not easy in the computer age to get people moving.
MsgId: *breakthrough(44)
Date: Wed Sep 3 22:06:44 EDT 1997
From: moderator At: 152.163.194.9
We need to discover an exercise to do while you're typing at your screen.Thank you for joining me tonight. And I wish you luck in finding ways to get people to exercise.
MsgId: *breakthrough(46)
Date: Wed Sep 3 22:08:52 EDT 1997
From: moderator At: 152.163.194.9
Dr. Snell: I enjoyed the chat. Goodnight to everyone.
MsgId: *breakthrough(47)
Date: Wed Sep 3 22:10:15 EDT 1997
From: moderator At: 152.163.194.9
Thanks for joining me. Goodnight. Please join me next week when I speak with Ken Nealson, Ph.D., of the University of Wisconsin, Milwaukee. Dr. Nealson will discuss the clues left behind by ancient forms of life.
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