Having a Nutrition Strategy Improves Endurance Performance


It never ceases to amaze me how few athletes young or older (not old!) go into an endurance race without a nutrition plan. Here is some recent research evidence from Denmark highlighting that using a scientifically-based nutrition plan can improve race speed by close to 5%.

The Research

The researchers investigated whether a marathon run (42.2 km) was completed faster by applying a scientifically-based rather than a freely chosen nutritional strategy. Importantly from an applied perspective, gastrointestinal symptoms were also examined and reported. 14 non-elite runners performed a 10 km running time trial 7 weeks before the Copenhagen Marathon 2013 for estimation of running ability. Based on that time, runners were divided into two performance-matched groups that then completed the marathon by applying either of two race nutritional (gels and water) strategies – one they chose themselves, the other scientifically-based and given to the runners in that group under instruction from experts in the sports nutrition field. Runners applying the freely-chosen nutritional strategy (n = 14; 33.6 ± 9.6 years; 1.83 ± 0.09 m; 77.4 ± 10.6 kg; 45:40 ± 4:32 min for 10 km) freely choose their in-race food and water intake. Runners applying the scientifically-based nutritional strategy (n = 14; 41.9 ± 7.6 years; 1.79 ± 0.11 m; 74.6 ± 14.5 kg; 45:44 ± 4:37 min 10 k time) were targeting a combined in-race intake of energy gels and water, where the total intake amounted to approximately 0.750 L water, 60 g maltodextrin and glucose, 0.06 g sodium, and 0.09 g caffeine per hr. Gastrointestinal symptoms were assessed by a self-administered post-race questionnaire.

The runners in the scientifically-based nutrition and fluid group took in the following:

  • 2 energy gels (each gel contained 20 g maltodextrin and glucose, 0.02 gm of sodium and 0.03 gm caffeine) and 200 ml of water 10-15 minutes before the start of the marathon
  • 1 energy gel after 40 minutes of running and 1 gel every 20 minutes after that until finishing
  • water was encouraged at every one of the 10 water stations with 750 ml per hour the recommended target with each station having each individual athlete’s recommended water intake. Runners were encouraged to stop and drink

The Results

Marathon time was 3:49:26 ± 0:25:05 for the runners applying the freely chosen and and 3:38:31 ± 0:24:54 hr for the scientifically-based strategy nutrition and water intake strategy. The difference was statistically significant and represented a 4.7% faster marathon when using the scientifically-based nutrition plan. Some of the runners experienced diverse serious gastrointestinal symptoms (e.g. urge to defecate, reflux, bloating, vomiting, abdominal pain, diarrhoea, muscle cramps, urge to urinate, dizziness), but overall, symptoms were low and not statistically different between groups.

So What?

The sport scientists concluded that non-elite runners completed a marathon on average 10:55 min (4.7%) faster by applying a scientifically-based rather than a freely chosen nutritional strategy with both groups having the same incidence of gastrointestinal upsets. In endurance races I often see or hear of well-prepared athletes who train the house down but forget race nutrition. These same athletes say they were worried about getting gut upsets, the lack of gels etc being available on the race course or hard to find and buy, or that simply did not know what the scientific principles of race nutrition are. These present findings tell you to learn what these principles are and prepare yourself rather than relying on the race organisers. When it comes to race day nutrition I’ve always worked on the 6P’s Principle – Perfect Preparation Prevents Piss-Poor (pardon the french!) Performance or another well known saying, Failing to prepare is preparing to fail. For more detailed information on nutrition before, during and after training or racing, see Chapters 6, 15 and 16 of my book The Masters Athlete.

Sources: 1. Hansen, E. and others (2014). Improved marathon performance by in-race nutritional strategy intervention, International Journal of Sport Nutrition and Exercise Metabolism, 24(6): 645-655. 2. Pfeiffer, B. and others (2012). Nutritional intake and gastrointestinal problems during competitive endurance events. Medicine and Science in Sports and Exercise, 44(2): 344-351. 3. O’Neal, E. and others (2011). Half-marathon and full-marathon runners’ hydration practices and perceptions. Journal of Athletic Training, 46(6): 581-591.