Question the basics5 min read . Updated: 06 May 2013, 09:09 PM IST
If you think you know the basics of sports nutrition, think again
Many of us think we know at least the basics of sports nutrition, but we rarely ever think about the logic behind these basics.
Peter Brukner, the doctor for the Australian national cricket team, in an editorial headlined “Challenging Beliefs in Sports Nutrition: Are Two ‘Core Principles’ Proving to be Myths Ripe For Busting?", in a yet-unpublished edition of the British Journal of Sports Medicine, poses these two simple yet complicated questions. Do you think you need to drink as much water as possible before, during and after exercise? And is low-fat and high-carbohydrate the optimum choice for diet control, general health and athletic performance? If you believe the answer is a yes to both, then think again.
One name that crops up again and again in this editorial is of Prof. Timothy Noakes from the University of Cape Town, South Africa, because he is considered an authority on both drinks and food in sports; a pioneer in thinking differently from conventional wisdom. I first met him during the “Sports Medicine Seminar" organized by the Lawn Tennis Association during Wimbledon 2004. Till then I had only read his research studies in peer-reviewed medical journals. I admired him as he didn’t shy away from questioning conventional wisdom, even if it meant taking on institutions that have an authoritative role in the world of sports and exercise medicine and science head on.
The delegates at the seminar were divided into two camps—those who worshipped Prof. Noakes, and those who hated him. He was questioning the then recommendations of the American College of Sports Medicine and US navy to drink water during activity. He suggested that our body was smarter than it was made out to be. Prof. Noakes said overhydration was the real danger, and not dehydration or heat stroke. In his 2012 book Waterlogged: The Serious Problem of Overhydration in Endurance Sports, Prof. Noakes explains how drinking too much water can lead to water retention and Exercise Associated Hyponatremic Encephalopathy (water intoxication). It can be fatal. He recommends that we drink according to thirst, not as much as we can. It will be different for all of us. We will need to start listening more to our bodies.
Today we have sufficient evidence to back up what he has been proposing for three decades.
Prof. Noakes is also the author of Lore of Running, a book often called the bible of running, for two reasons. First, its sheer size, and second, because it covers all there is to know about running and can be used by coaches, runners, sports doctors and scientists. Also, Prof. Noakes says he is first and foremost a scientist, so he will only talk about something when he thinks there is sufficient scientific evidence to back it.
Lore of Running popularized “carb-loading", where runners eat lots of carbs the night before a marathon, a practice that is now widely followed by every kind of distance runner.
High-carbohydrate and low-fat intake formed the very basis of nutritional advice for athletes in that ground-breaking book. But once he realized that he was wrong with his “high-carbohydrates" advice, since carb-loading is specific to endurance running, he openly apologized for his “mistake" in another book, the recent Challenging Beliefs: Memoirs of a Career. He was widely criticized for his new view—of a diet high in proteins and fats and low in carbohydrates.
He put forward a very simple question: If a low-carbohydrate intake is healthier than we expect, then why is it a hidden fact? As Prof. Noakes says, “There is a saying that to find the root cause, follow the money trail."
Some would remember the popular low-carbohydrate/high-protein/high-fat diets, Atkins and South Beach, both of which were rubbished by the medical fraternity as “fad diets". There was some interesting argument against the low-carb/high-fat diet, which was more coincidental than evidence-based. Evidence was emerging of a possible link between cholesterol and atherosclerosis, suggesting fat was bad, without wanting to understand the science behind it. It reinforced the message that fatty food led to fatty arteries in fat people. Let’s take a relook at this.
The real culprit, as suggested by low-carbohydrate advocates, is the hormone “insulin", which in excess, like all things in life, is poisonous. It is a hormone released by the pancreas in response to carbohydrates, not fats or proteins. Meals high in carbohydrate content stimulate high insulin release. After the initial high blood glucose, insulin makes it drop down, leading to further hunger, and a craving for more carbs. A paradoxical situation, eating makes you hungry. Over time, high levels of insulin release can lead to insulin-resistant diabetes like type 2 diabetes. Insulin is also responsible for conversion of excessive carbohydrates to triglycerides in the liver, which are then released in the bloodstream.
Carbohydrates, when ingested, make you want to eat more, unlike fat or proteins. Once you are full, they don’t make you hungry again. This automatically reduces the quantity of food intake. Prof. Noakes points out an interesting fact, that the human intestines are especially well designed for digesting high-protein foods and bear more resemblance to that of the carnivorous lion than that of our nearest living relatives, fruit- and plant-eating chimpanzees. Cereals and grains have been a staple of the human diet for only the past 20,000 years, whereas we began to eat meat perhaps 2.5 million years ago.
Prof. Noakes has himself been a runner for over 42 years, but admits that the numerous benefits of exercise do not include any sustained effects on weight loss. For that you need to pay more attention to what you eat, but not by cutting down on the amount—that will happen automatically.
Now imagine this coming from me, a fanatic runner and a vegetarian by choice. I, like Prof. Noakes, simply stand by evidence, not by emotional gut feel.
Rajat Chauhan is an ultra marathon runner and a doctor specializing in sports and exercise medicine and musculoskeletal medicine, and founder of Back 2 Fitness. He is also associate editor, British Journal of Sports Medicine.