Runner receiving food at a marathon (© Getty Images)
The IAAF has today released a comprehensive guide to sports nutrition designed to offer athletes the latest information on fueling their training and performance.
The IAAF Consensus Statement on Nutrition for Athletes, published in the International Journal of Sports Nutrition and Exercise Metabolism, includes a summary of the latest scientific developments relevant to athletes and 16 articles on different facets of sports nutrition.
Led by Lindy Castell from Green Templeton College at Oxford University and Louise Burke, the Head of Sports Nutrition at the Australian Institute of Sport, a team of 50 experts looked at a range of new developments in sports nutrition to see how they apply to the five core areas of athletics: sprints, jumps/throws/combined events, middle distance, long distance and ultra distance/mountain running. Their findings, divided into 12 key themes, form the backbone of the report.
“Sports nutrition is a dynamic and constantly evolving science,” Burke said. “The 2019 IAAF Consensus Statement on Nutrition for Athletics updates athletes, coaches and their entourage about changes in the knowledge and practice of nutrition for performance and health over the past decade.”
In the wake of similar studies conducted in 1995 and 2007, Burke said, the IAAF Health and Science Department charged a group of international experts to summarise cutting edge science and its translation into practice across all the event groups in athletics.
“A key message is that each athlete should have an eating plan that is personalised to their event and individual needs, periodised to address shifting goals and training practices across micro- to macro-cycles of the annual plan, and able to be put into practice in every environment experienced by the athlete,’’ she said.
A personalised programme, “achieved by teamwork between the coach, athlete, and sports science and nutrition experts, will help the athlete reach performance goals as well as achieving a long career through management of the risk of illness and injury.”
Burke said that the studies have highlighted new insights around the risks of Relative Energy Deficiency in Sport, or RED-S, which can occur when athletes consume less energy than they are expending. The studies also looked at intake of fluid and fuel in longer events, nutrition strategies for altitude and performance in the heat, and evidence-based uses of sports foods and supplements.
“We look forward to this project guiding the preparation of all athletes - from throwers to ultramarathon runners, and from sprinters to race walkers - in their key events, from the Doha World Championships and Tokyo Summer Olympic Games and beyond.”
Some of the key findings from the Consensus Statement:
• The usefulness of high-fat, low-carbohydrate diets is limited to selected individuals, events or scenarios in distance events.
• Low Energy Availability, which can result when athletes consume less fuel than they are using, is a primary cause of RED-S, formerly known as Female Athlete Triad syndrome, in which disordered eating, loss of menstruation and osteoporosis occur, but can also contribute to reduced testosterone levels and libido in men, poor bone health, increased risk of illness and injury, gastrointestinal disturbances, cardiovascular disease, impaired training capacity and performance.
• Low Energy Availability is known to be a major risk factor in the development of bone stress fractures and should be corrected in both the prevention and treatment of such problems.
• A food first philosophy is promoted in relation to nutritional needs, and supplements should only be used under supervision to treat or prevent nutrient deficiencies. Only five supplements have an evidence base of contributing to performance: caffeine, creatine, nitrate/beetroot juice, beta-alanine and bicarbonate. But there is a risk of ingesting banned substances in the use of any supplements.
• Nutrition can help during the rehabilitation of muscular injuries. Goals should include adjustment to new energy requirements and distribution of protein intake to minimise the loss of lean mass and increase muscle repair.
• No direct benefits have been associated with the avoidance of gluten by clinically healthy athletes.
• Vegetarian diets can theoretically support athletic demands, but special attention and good planning are required to ensure adequate intake of energy and specific nutrients that are less abundant or less well absorbed from plant sources (eg. iron).
• Evidence that carbohydrates (CHO) consumed during exercise can provide an additional benefit via the brain and nervous system. CHO can stimulate areas of the brain that control pacing and reward systems via communication with receptors in the mouth and gut. This “mouth sensing” of CHO provides another reason for frequent intake of CHO during longer events, and shorter ones in which it may not be necessary to provide muscle fuel.
You can read the articles here.