Track and Field (Sprints, Jumps, and Throws)

Track and field competition includes a number of events of short duration that rely on power through anaerobic energy. Sprints and hurdle events include races up to and including 400 meters, while field events include jumps and throws of short duration and maximal effort. There is evidence that male and female sprinters, jumpers, and throwers have less than optimal nutrition habits, with a majority having below-standard intakes of at least one vitamin or mineral.⁵¹ There is also evidence that stress fracture risk, considered an outcome of inadequate energy and calcium intake, is high in track and field athletes.⁵²

It is hard to imagine an overweight sprinter, strongly suggesting that aerobic activity is not necessary for lowering body fat. A study assessing the fat-lowering impact of high-intensity versus low-intensity activity found that they were equally effective in lowering body fat.⁵³ Sprinting has been recommended as a normal component of interval training in many sports. Regardless of whether it's done for training or it represents the sport itself (as in the 100-meter dash), sprinting has specific energy requirements that must be accounted for and satisfied to perform optimally. Sprints, which by their very nature rarely last longer than 10 seconds, primarily use the fuels phosphocreatine and glycogen. Muscles with an adequate storage of phospho creatine can support high-intensity exercise for 8 to 10 seconds, making it likely that most athletes use primarily phosphocreatine for the entire duration of the sprint. A study assessing creatine monohydrate supplementation found that it increased the muscular storage of phosphocreatine, promoted gains in fat-free (i.e., muscle) mass, and improved sprint performance.⁵⁴ This is consistent with a number of studies in other sports that produced similar findings.⁵⁵ Carbohydrate intake also makes a difference in sprint performance. In a study evaluating the impact of high-, moderate-, and low-carbohydrate intakes, the high-carbohydrate intakes produced better initial sprint performance than did lower carbohydrate intakes.⁵⁶

In some sports, the "sprint" may be the difference between winning or losing even when the majority of time is spent on lower-intensity activities. For instance, 10K runners and marathoners run almost the entire distance at the highest pace at which they are capable of sustaining aerobic metabolic processes. At the end of these races, however, the athlete goes into a sprint pace (referred to as the "Kick" that exceeds his or her oxidative capacity. A study emulating this high-pace aerobic running followed by an anaerobic kick found that a higher carbohydrate intake aided performance.Over 4 consecutive days, a high carbohydrate intake, when compared with a moderate carbohydrate intake, was more capable of maintaining muscle glycogen in athletes .working at a high intensity of aerobic capacity (~75 percent of VO2max) followed by five 1-minute sprints.⁵⁷

Keeping this in mind, track and field athletes must consider the following nutritionally relevant factors for their sport.

Sprinting demands a large amount of phosphocreatine and carbohydrate fuels. By its very definition, a sprint requires the fastest possible movement over a short prescribed distance. Metabolic limitations control the maximum distance humans can sprint, and sprints never last longer than 1.5 minutes. During short sprints, there is a primary dependence on phosphocreatine as a fuel. It has been hypothesized that the ingestion of extra creatine, typically as a supplement in the form of creatine monohydrate, may improve phosphocreatine storage. This increased storage of phosphocreatine could increase the number of short all-out sprints an athlete is capable of performing and might also improve the maximal time muscles can rely mainly on phosphocreatine as a fuel. There is evidence that supplementing with creatine monohydrate does, in fact, improve both sprint frequency and sprint distance. However, inherent design weaknesses are present in some of these studies, so athletes should refrain from jumping on the creatine supplement bandwagon. For instance, these studies did not evaluate the energy intake adequacy of the athletes, so the inherent limits of synthesizing creatine without adequate energy may have been inhibiting performance, a problem that could be more easily and cheaply resolved through a greater energy intake, preferably from carbohydrate. Also, the issue of the safety of frequent and long-term creatine monohydrate ingestion has not yet been adequately addressed.

Creatine is a normal constituent of the diet and is plentiful in meats (beef, pork, poultry, fish). Therefore, in the context of a high-carbohydrate diet, it seems useful for sprinters to consider consuming small amounts of lean meats regularly. For nonmeat eaters, care should be taken to consume sufficient protein and calories so the synthesis of creatine can occur in the body. However, even more important than protein intake is satisfying total energy requirements so the athlete is capable of synthesizing all the creatine needed to sustain optimal performance.

Pure sprinters may be inhibited by carbohydrate supercompensation, while endurance athletes may require carbohydrate supercompensation to support the end-of-race "kick".Pure sprinters must move their mass quickly over a relatively short distance, and the amount of mass that must be moved is a factor in how quickly it can be moved. Sprinters with high strength-to-weight ratios have advantages over those with lower strength-toweight ratios. One of the effects of carbohydrate loading (or super compensation) is to force more carbohydrate (glycogen) into the muscles so it is available for muscular work. Glycogen is stored with water in a 1 to 3 ratio. That is, for each gram of glycogen stored, the body stores 3 grams of water. At times, athletes who undergo a carbohydrate-loading regimen mention that they feel stiff and heavy. Clearly, this is not the way a sprinter should feel at the beginning of a race, but it is a perfectly acceptable feeling for long-distance runners. Therefore, pure sprinters should regularly consume a high-carbohydrate intake that provides sufficient total calories but should avoid any carbohydrate-loading regimen that might force additional glycogen and water into the muscles.