FAT FREE: Elite athletes have to eat well and train hard to maintain such low levels of body fat.
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Having won six medals in his career, Seattle-based speed skater Apolo Ohno stands to make U.S. Winter Olympic history if he wins another one in upcoming short-track competition—the 1,000-meter race this weekend or the 5,000-meter relay on February 26. In various reports, Ohno has said that he's in the best physical shape of his life, weighing five kilograms less than he did for the 2006 Games in Torino, Italy, and nine kilograms less than he did for the 2002 Salt Lake City Olympics. Ohno is now 65 kilograms of almost pure muscle: only 2.8 percent of his body consists of fat.
Elite athletes, of course, are expected to be slimmer than the rest of us. The average amount of body fat in the U.S. is 22 percent for men and 32 percent for women, although most experts believe a healthier body-fat content is 15 percent for men and 22 percent for women, according to The Ultimate Fit or Fat, a book by nutritionist Covert Bailey. Ohno's fat level, though, is down there even for an athlete.
So how low is too low? After all, fat is crucial for normal physiology—it helps support the skin and keep it lubricated, cushions feet, sheaths neurons, stores vitamins, and is a building block of hormones.
Marina Mourtzakis, an assistant professor at the University of Waterloo in Ontario who specializes in nutrition, exercise and metabolism, gives ScientificAmerican.com the skinny on athletes' fat.
[An edited transcript of the interview follows.]
How do athletes achieve such lean physiques?
It takes a long time to achieve and maintain these low levels of body fat. It really comes down to balance. Energy in equals energy out. With increased energy expenditure and lower caloric intake, you can tip the scale to reduce weight.
Is it safe for them to get down to 2 percent body fat?
Athletes have to take in adequate amounts of protein to maintain muscle mass, and they still have to take in adequate amounts of carbohydrate to maintain optimal training intensities. If they do this properly, they can maintain heavy workout sessions and lose fat without compromising their performance.
So 2 percent would be a safe lower limit if athletes eat right. What sort of diet should they have?
Meat, fish, poultry and dairy are good protein sources. But they also need to take in a fair amount of carbohydrates. When you're training at high intensities, you're burning more carbs. When those stores deplete, your body has to use something else—this could be fat, but it could be protein. People don't always appreciate how difficult it is to lose fat without losing protein. For athletes to maintain a high level of performance and low body fat, it means they have to a have a really good balance in their diet in order to maintain their health.
Should athletes continuously strive to lose body fat?
Athletes should not be "dieting" three to four months prior to a major competition. They should be weight stable by the time the competition date arrives. Any changes in weight, if an athlete has that as a goal, would happen much earlier in training to avoid problems with performance and potential injury.
Is it physically desirable to be below normal body fat levels?
It really depends on the sport an athlete is involved with. For example, snowboarders probably have a normal amount of fat, whereas long-distance and endurance athletes [like speed skaters, cross-country skiers and biathletes] likely have less.
Several techniques can estimate body fat composition: Skin-fold measurements; bioelectric impedance tests, which use a small electrical current to estimate the amount of water in the body and then extrapolate a fat figure; and tests based on displacement of water (hydrodensitometry) or air (the "Bod Pod"). How good are they?
They're not very accurate. Dual-energy x-ray absorptiometry [DXA—the same technology used to measure bone mineral density], magnetic resonance imaging and computed tomography are highly precise—[each] can measure fat to within 2 percent accuracy. DXA is probably most common in research, because MRI and CT [which can also determine body composition] are so expensive and inaccessible.
Editor's note (2/19/10): A clarification was added to a question after posting to address a comment.
Editor's note (2/22/10): Professor Mourtzakis wanted to emphasize the risks associated with an extremely low body fat: "While it is possible for some athletes to reach 2 percent body fat, I would certainly not support this approach for athletes. Achieving this range presents health risks, including increased risk of infection and injury. This approach often supports unhealthy eating behaviors and patterns that are reflective of disordered eating behaviors. It is especially important for athletes to maintain adequate intake of all macronutrients (that is, protein, carbohydrates and fats) to achieve optimal performance and maintain their health."
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16 Comments
Add CommentThis article didn't seem to answer its own question.
Reply | Report Abuse | Link to this"they still have to take in adequate amounts of carbohydrate to maintain optimal training intensities"
Reply | Report Abuse | Link to thissorry, this is wrong. walk into any crossfit gym to see lean strong athletes training intensively who fuel their muscles on fatty acids.
and, depending on the sport, leaner is not necessarily better. somewhere above zero and below 20%... for someone who's too lean, a few pounds of extra fat can allow better training and performance.
"they still have to take in adequate amounts of carbohydrate to maintain optimal training intensities"
Reply | Report Abuse | Link to thissorry, this is wrong. visit any crossfit gym to see lean strong athletes, training intensively with muscles fueled by fatty acids.
zero body fat is not best, and leaner is not always better. depending on the sport, a good reserve of stored body fat allows better training and performance. even better when you have trained your muscles to run on stored fat.
It depends upon the sport.
Reply | Report Abuse | Link to thisProfessional cyclists are notoriously slim with very low body fat levels - but even they range from 5 to 15 percent.
I agree that this article really did not answer its own question.
Yes, the article answers its own question. How low can an athlete go? Well, we have Ohno at 2.8% body fat, how much lower? He could starve himself to death and go even lower. Second part of the question, is it wise? I will assume that Ohno (and his trainers) know what they are doing. Further the article makes it clear that it is a delicate balance to achieve such a low body fat AND maintain optimum performance. It also makes clear that individuals vary as do the demands their individual sports place upon them. What more do you ask from an article seven paragraphs long with 5 questions and answers?
Reply | Report Abuse | Link to thisUmm... they answered the initial question but not "... so lean, and is it wise to do so?"
Reply | Report Abuse | Link to thisThere's no mention of long term effects of treating the body like this. Do athletes suffer from any chronic ailments after their careers are done?
ummm... it answers the initial question but not "...get so lean, and is it wise to do so?"
Reply | Report Abuse | Link to thisThere's no mention of long term effects of this type of training. Do pro athletes that do this for a long time suffer later in age? Are there any chronic ailments associated with aging athletes that could be connected to such extreme dietary conditioning?
sorry for double (ah... tripple post)
Reply | Report Abuse | Link to this@Scientific America: You need to sort out the registration whilst posting system!!!
unless the brain becomes vastly evolved, the body will always have some BF. At 3 pounds it is almost all fat therefore a 150 pound man/woman will have a 2% BF for this reason alone. As the speed events, just like cars, power to weight ratio rules in a sprint (and even at the end of a long race, you still have to sprint/accelerate) to win. Lance Armstrong was known for having lost 10 pounds during chemo giving him one of the highest power to weight ratios on the tour. Ohno should be in the same boat. If his training and lack of BF affects testosterone production (and probably other hormones), then he is hurting himself, but he races are way to short to really get into fat burning unless he is training for this with a low carb diet (which will salvage his T production according to studies). The fact is he is one of the best in the world so what if he is 2% BF. Some can hang with that, some can't, scientist want everyone to conform to a simple formula for health in spite of the thousands of SNP's on our DNA that would suggest some would do better with more BF and differing diets. All said, if it ain't broke don't fix it. Watching him this year compared to past years he is remarkable better/faster/quicker.
Reply | Report Abuse | Link to thisI'm surprised there's no discussion of impaired immune response that's often a result of too-low body fat levels. There's solid science dating back 40 years that shows a clear link between the two. Most sports nutritionists say that 4-5% is as low as male endurance athletes should aim for. Below that, one runs the risk of falling prey to viral and bacterial infections.
Reply | Report Abuse | Link to thisTo compare crossfit to an elite world class athelete, that made me chuckle. Sorry but you cannot compare a wolrd class athelete who trains 4 or more times a day to someone that trains one time a day.
Reply | Report Abuse | Link to thisThis article is way off on the actual levels of body fat athletes carry. Leigh Peele just put up an article discussing this and I think you and your readers will find it very useful.
Reply | Report Abuse | Link to thishttp://www.leighpeele.com/body-fat-pictures-and-percentages
I'm highly dubious of Ohno being 2% body fat. That is pro bodybuilder range.. and Ohno looks nothing like a pro in contest shape. The first give away is that his face isn't drawn and gaunt.
Reply | Report Abuse | Link to thisRegardless of how one feels about the aesthetic appeal of bodybuilding, the fact is that they are clearly the leanest of all athletes on contest day. Especially when you take into account total body mass.
Of course a contest is nowhere near as strenuous as a skating match, but the heavy training up to a contest involves many hours a day of lifting and cardio training on very diminished calories to achieve the absolute lowest amount of body fat humanly possible.
The Olympic athletes are lean, but as a general rule few of them come close to the lowest levels that can be achieved (albiet for a short duration of time)
http://img16.imageshack.us/img16/8176/leanbodybuilder.jpg
Take into account that his diet is relative to what calories he burns in training to get to this BF%,I would expect him to be taking in carbs ,fat and protein balanced to what is burned. That being assumed he would or should not have any detrimental effects of such low body fat numbers.The normal individual not going through proper testing to measure there true caloric use would be wise to avoid such a low number as a norm.
Reply | Report Abuse | Link to thisGiven that neurons are wrapped in fat, isn't the real risk that too low a level of fat will "strip" neurons of their fat. I have heard of cases where people suffered memory loss from (inappropriately) using cholesterol lowering medication. Is this just a myth?
Reply | Report Abuse | Link to thisI'll never have to worry about too little body fat. My interest is if there is a truly healthy range for body fat for men and/or women and if this range varies with age. As I am getting older, it seems like any unnecessary body fat just serves to put more pressure on joints and all organs in general. Assuming some normal activity level that includes daily exercise, I would think that a body fat percentage window would be a much better target to shoot for than just weight (or the changing BMI that is so often used).
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