If you are gearing your training for the upcoming marathon season, including developing aerobic power, exercising at a large fraction of this power, focusing on form, foot placement and high running economy including getting yourself several pairs of Nike’s record breaking Vaporfly Next% shoes. Together with strengthening high mental fortitude – mind over muscle, purpose, motivation and the ability to ignore usual physical cues like pain, dehydration, tired muscles, a pounding heart and going beyond the brink.
The only thing you will need to consider is how to fuel your muscles and improve your lactate threshold for marathon preparation and racing.
In ‘Advanced Marathoning (2nd Ed),’ Peter Pfitzinger and Scott Douglas point out that two factors that typically conspire to make you slow in the last few miles of the marathon are glycogen depletion and dehydration.
The race nutrition strategy that Pfitzinger and Douglas suggest to improve energy stores is to elevate glycogen in the body by consuming a high level of carbohydrate. The harder you run, the higher the proportion of carbohydrate you use; the slower you run, the higher proportion of fat you use.
In ‘Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers,’ Burke LM, Jeukendrup AE, Jones AM, Mooses M. (Int J Sport Nutr Exerc Metab. 2019 Mar 1;29(2):117-129. doi: 10.1123/ijsnem.2019-0004. Epub 2019 Apr 4. Review), propose that ideal race nutrition strategies should focus on carbohydrate-rich eating in the hours per days prior to the event to store glycogen in amounts sufficient for event fuel needs, and in some cases, in-race consumption of carbohydrate and fluid to offset event losses.
Beneficial carbohydrate intakes range from small amounts, including mouth rinsing, in the case of shorter events to high rates of intake (75-90 g/hr) in the longest races. A personalized and practiced race nutrition plan should balance the benefits of fluid and carbohydrate consumed within practical opportunities, against the time, cost, and risk of gut discomfort (if you need to stop or slow-down for fuel intake, the cost is too high).
In hot environments, prerace hyper-hydration or cooling strategies may provide a small but useful offset to the accrued thermal challenge and fluid deficit. Sports foods including drinks and gels may assist in meeting training and race nutrition plans, with caffeine, and, perhaps nitrate (e.g. concentrated beetroot juice) being used as evidence-based performance supplements.
However, Burke LM, Jeukendrup AE, Jones AM, Mooses M., comment that nutrition-related contributors including body mass and body shape and size (anthropometry), capacity to use fuels, particularly carbohydrate to produce adenosine triphosphate economically over the duration of the event, and maintenance of reasonable hydration status in the face of sweat losses induced by exercise intensity and the environment vary from athlete to athlete and require pre-race conditioning and practice.
Burke LM, Jeukendrup AE, Jones AM, Mooses M., look to the dietary practices of East African runners as an ideal, notwithstanding various potential contributing factors for their superior performance from high altitude training to specific anthropometric features.
While dietary surveys of Kenyan and Ethiopian runners have been limited to their home environments and training camps, evidence shows that they maintain their eating practices on the competition circuit or in their Northern Hemisphere training bases because of the low cost and cultural familiarity, as well as self-belief that it might contribute to their success.
The researchers note that diets of East African runners contain substantially different contributions of foods and macronutrients compared with Western practices.
Typically, carbohydrate supplies 60–80% of energy, with high reliance on vegetables (80–90% of diet) rather than animal food sources (10–20%), and limited food variety, with staple foods comprising rice, pasta, potatoes, porridge, cabbage, kidney beans, ugali maize meal, and injera flatbread.
Approximate fluid choices include water (0.9–1.1 L/day) and tea (∼0.9 L/day) with brown sugar and (for Kenyans) milk.
Daily energy intake is distributed over a small number of meals, with prolonged moderate- to fast-paced morning runs being undertaken before breakfast and with nil/minimal intake of fluid.
Meanwhile, meals are consumed soon after training sessions, and high-intensity track sessions are completed as a midmorning workout after breakfast. Indeed, many concepts of periodising carbohydrate availability according to the needs of the session appear within these traditional practices.
Although supplements are rarely used, data from observational studies and accounts of recent attempts on world marathon records by male runners note personalised race nutrition plans including proactive intakes of fluid and carbohydrate, often with the involvement of Western sports scientists.
Interestingly, Burke LM, Jeukendrup AE, Jones AM, Mooses M., highlight the reported or suspected prevalence of acute or chronic periods of low energy availability among these East African athletes relative to calculated or expected exercise energy expenditures for these middle- and long-distance athletes. In other words, these athletes reduce food intake including carbohydrates leading-up to important races.
Burke LM, Jeukendrup AE, Jones AM, Mooses M., put this down to a combination of cultural eating patterns, from a fiber-rich unvaried diet and few eating occasions in a day, food insecurity, and the interaction with high training loads resulting in lack of intake during training hours as well as post-exercise appetite suppression.
Further, East African athletes report that their “ideal racing weight” is lower than their normal training body mass.
Based on sources and evidence reviewed, high consistent daily carbohydrate intake seems to be essential for a sub 2-hour marathon, at least in the months and several weeks before your marathon. So it’s best to factor carbohydrate intake in your diet sooner rather than later.
Fat is not essential in the quest for a record breaking marathon – Pfitzinger and Douglas point out that even the most gaunt marathoner has a stockpile of fat for several marathons – fat is relatively unlimited, whereas carbohydrate reserves are much more limited.
Most importantly, the key nutrition strategy, in addition to reducing calories from carbohydrates, is to reduce fiber in the days before the race, as this will help to prevent an upset gut as well as reduce body weight and excessive water retention, thereby improving power to weight ratio.
What’s your nutrition strategy for important races, and do you have any dietary tips or secrets to share?