Magazine headlines love to sensationalize the idea of “eat more to weigh less.” These articles lead us to believe that if we consume more calories we will look like the hot chick on the front cover and/or have the best race season of our lives. While much of these articles are based on weak science or all out b.s., there is some merit to watching what you eat and not falling behind on calories. A recent study at the Laboratory for Elite Athlete Performance at Georgia State University cuts to the truth of the matter.
Most studies analyzing energy surplus/deficit focus on the difference between calories consumed versus calories expended over periods of time usually measuring a full day or many consecutive days. The study out of Georgia took a unique approach measuring calorie surplus/deficit by the hour. They found that the athletes with the fewest hourly deficits of 300+ calories maintained the lowest body fat percentage.
This finding coincides with a idea put out there in a conversation I recently had with a boss of mine at the South Yuba Club. His theory is that many people who attend high intensity group exercise classes fail to lose weight, despite their high level of physical activity, because they go through class with a huge calorie deficit then overeat after class.
What are the implications for triathletes and other endurance athletes? A full third of the study participants were middle- and long-distance runners, making the findings very applicable to us triathletes. What the study does not tell us is how the calorie deficit came to be. Did the runners go in to deficit before practice and train on an empty stomach? or did they stay fueled throughout the non-training portion of the day and then exercise for several hours without fueling during exercise? This, we don’t know. In the absence of this data we must focus on the conceptual message uncovered during the study: Don’t starve yourself and expect to lose weight.
Source: Deutz, et. al. Relationship between energy deficits and body composition in elite female gymnasts and runners. Laboratory for Elite Athlete Performance, Center for Sports Medicine, Science & Technology, College of Health and Human Sciences, Georgia State University, Atlanta, GA 30303. http://nutritiming.com/docs/Energy_Deficits_and_Body_Comp_MSSE.pdf