In sports science, there鈥檚 sometimes a disconnect between those who conduct research in laboratories and those who work directly with elite athletes in the field鈥斺,鈥 as sports nutritionist Louise Burke . Both groups have valuable perspectives, but I find that the best advice comes from those who manage to straddle both sides of the divide.
On that note, I attended a presentation by Jennifer Sygo at in Toronto. Sygo currently serves as a dietitian for the Canadian track and field and gymnastics teams, as well as the Toronto Raptors basketball team. On the side, she鈥檚 working towards a PhD at Manchester Metropolitan University, based on her work with the gymnasts. Her talk focused on sports nutrition for endurance athletes, and it included some ideas and perspectives I hadn鈥檛 encountered before. Here are a few highlights that stuck with me:
Dial Up the Carbs
I鈥檒l start with the least surprising message from Sygo鈥檚 talk: endurance athletes need carbohydrates, and lots of them. She covered the research suggesting that low-carb ketogenic diets don鈥檛 improve performance in Olympic-distance endurance events like the marathon, while acknowledging that ultramarathoners might choose to make different trade-offs. Elite marathoners, she pointed out, get about 85 percent of their in-race energy from carbohydrates, with most of that coming from glycogen stored in the muscles and the remainder from glucose in the bloodstream.
To keep those carb reservoirs fully stocked, she shared some specific carbohydrate intake goals she uses with elite runners for various distances:
- The day before a 10K, fill up your muscles with glycogen by aiming for 7 to 12 grams of carbohydrate per kilogram of bodyweight (g/kg). On race day, take in 1 to 4 g/kg between one and four hours before the race. If you weigh 155 pounds, that works out to between 70 and 280 grams of carbohydrate鈥攁 pretty wide range that reflects the individual variation in how well people can handle a meal before exercise. For reference, a breakfast of 鈪 cup of oats, a cup of berries, and a cup of fruit juice gives you 100 grams of carbs.
- For a half marathon, follow a similar approach, and then鈥攁n approach I hadn鈥檛 considered鈥攖op up your carb stores with a gel or sports drink after your warm-up. She also suggested considering taking in some carbs during the race, or at least some sports drink to get the brain benefits. I don鈥檛 usually think about in-race nutrition for a race that short, but then again Geoffrey Kamworor when he broke the half-marathon world record a few years ago.
- For a marathon, increase the pre-race loading to 10 to 12 g/kg for 36 for 48 hours beforehand. That鈥檚 an enormous amount, which you鈥檒l probably only achieve by drinking some juice or sports drink in addition to carb-heavy meals. Top up in the morning, and again after your warm-up, and then aim for somewhere between 30 and 90 grams of carbohydrate per hour during the race. (I鈥檒l add that some pro cyclists鈥 鈥攁re now pushing closer to 120 g/hour, but I鈥檓 not sure how well that would translate to running.)
Don鈥檛 OD on Veggies
Yes, this message surprised me鈥攂ut read on to see what she meant. One of the big trends in sports nutrition over the past decade has been the idea that, instead of just eating the same things every day, you should adjust your intake to match your expenditures. Sygo showed slides of the , a concept developed at the University of Colorado Colorado Springs along with the U.S. Olympic Committee that offers visual guidance for how you might eat during periods of light, moderate, and heavy training. You can see the three plates .
On the easy training plate, vegetables and fruits take up half the plate. On the hard training plate, vegetables take up only a quarter of the plate (though fruit has been moved off the plate, since there鈥檚 no room for it!). The point isn鈥檛 that vegetables are bad. Quite the contrary: they鈥檙e essential. But if you鈥檙e training hard, your caloric needs are through the roof, and you can鈥檛 rely on vegetables alone, or even predominantly vegetables, to get you there. They鈥檙e simply not calorie-dense enough, and their high fiber content makes them too filling and laborious to eat.
A common trap, Sygo pointed out, is the 鈥溾濃攁 frequent sight when health-conscious endurance athletes gather. You feel like you鈥檙e eating an enormous meal, but if you鈥檙e not careful it won鈥檛 have as many calories as your stomach is telling you. Given the growing understanding of the downsides of (often unintentional) underfueling, it鈥檚 worth keeping calorie density in mind. Grains and fats are good options, along with subtler tweaks. For example, the easy training plate includes only fresh fruit; the moderate and hard plates add stewed and dried fruits.
Eliminate Dead Weight
There鈥檚 no delicate way to say this: you鈥檝e got one to two pounds of fecal matter in your colon, and getting rid of it before a competition might give you an infinitesimal edge. One approach that athletes in weight-sensitive sports have long used is a temporary low-residue diet鈥斺渞esidue鈥 being the undigested fiber, bacteria, and water that鈥檚 left over after you鈥檝e digested the good stuff. In practice, that means cutting way back on fiber for a few days.
Researchers at Liverpool John Moores University in Britain tested this approach in . They had 19 volunteers cut back from their typical 30 grams of daily fiber to less than 10 for four straight days, while maintaining the same overall calorie content and macronutrient distribution in each meal. The result: average weight loss of 1.3 pounds, presumably mostly poop. The other result: harder stools and half as many bowel movements, though 18 of 19 volunteers said they鈥檇 be willing to repeat the intervention.
There are other reasons you might be interested in a pre-race low-residue diet. A few years ago, pro cyclist Mike Woods told me he follows a 鈥渇ive-year-old鈥檚鈥 low-fiber diet prior to races, not to lose weight but to minimize GI upset. For most of us, losing a pound wouldn鈥檛 be worth the hassle. Even for elites, Sygo noted, it鈥檚 marginal. She broached the topic with a track athlete recently, but didn鈥檛 get far before the athlete cut her off with some version of: I鈥檒l do anything to win, but not that.
Pump Your Iron Up
Sygo isn鈥檛 a supplement pusher. She noted four relevant and evidence-backed ergogenic aids for track athletes: beta-alanine, sodium bicarbonate, creatine, and caffeine. Only the last one has been shown to reliably work for long-distance events. (That鈥檚 consistent with a recent , though they also included nitrate on their list.) She also noted some key parameters to monitor on an ongoing basis: vitamin D, vitamin B12鈥攁nd iron.
The risk of low iron is a familiar topic for endurance athletes. I鈥檝e written before about what thresholds to watch out for and how to get your levels up. Sygo鈥檚 target are similar or perhaps a little higher: she suggests aiming for ferritin levels of at least 30 micrograms/L in women and 50 micrograms/L in men. For hemoglobin, she suggests a target of at least 130 g/L for both men and women. The usual minimum threshold for hemoglobin in healthy women is a little lower, but it鈥檚 not clear whether that鈥檚 really optimal, or just reflects the fact that women tend to have lower (and perhaps suboptimal) hemoglobin levels primarily due to menstruation.
One of the particular challenges for athletes is that heavy exercise produces elevated levels of for up to six hours after training. As a result, Sygo suggests taking supplements away from training time, ideally on an empty stomach, with vitamin C to aid absorption. She also noted a further twist: U.S. Army researchers that in addition to being triggered by exercise itself, hepcidin is further triggered if you don鈥檛 get enough calories to replace what you burn. That鈥檚 yet another reason to avoid underfueling.
I should emphasize that I鈥檝e cherry-picked the bits of Sygo鈥檚 presentation that I found most interesting or unusual. In practice, it鈥檚 the big picture that matters more than the little details. Still, getting your sports nutrition right requires a lot of trial and error, because everyone鈥檚 different. You鈥檒l need to experiment to find out which approaches work best for you, and that definitely means rehearsing in training everything you want to try in competition. And in the end, it鈥檚 the fundamentals that matter most: eating a healthy, balanced, and calorically sufficient diet is going to do way more for your performance and health than dropping a pound of poop.
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