A recent study on the eating habits of 553 elite athletes participating in strength, endurance and team sports revealed that their diets often provide less than the daily recommended vitamin intake. In addition to a healthy diet, researchers therefore also recommend taking a daily low-dose multivitamin pill as extra ‘insurance’.
The athletes in the study reported on their daily consumption of regular food, plus sports foods and any nutritional supplements. In an additional study, data from 778 sportspeople was analysed for the use of nutritional supplements, sports foods and any advice received. Floris Wardenaar explains: ‘It is the first major nutritional study among Dutch sportspeople since 1989, and one of the largest in the world.’ Wardenaar completed his PhD in February at Wageningen University & Research, with a study on the diet and use of supplements among Dutch elite and sub-elite athletes.
Nutrition influences performance, recovery and health
The above applies to all of us, but even more in the world of sports, where these types of details can make the difference between a medal and no medal. ‘For example, we noticed that iron intake is an issue among women in particular, as a deficiency can reduce exertion capacity. And consuming too little fuel in the form of carbohydrates limits maximum performance, despite the obvious potential training benefits.’
A small multivitamin providing 50-100 per cent of the daily recommended intake will not guarantee our athletes a medal straight away. ‘The effects of deficiencies do not become apparent until much later, and we are still not sure whether their performance is even suffering,’ says Wardenaar. ‘But given their level of activity, the vitamin intake of these sportspeople should be above that of the average person at the very least. Only half of them are reaching this basic level, however, and some are even below it. So there is certainly room for improvement.’
The data also revealed scope for nutrition to be tailored more effectively to training schedules. ‘Total protein intake is satisfactory among 80 per cent of athletes. Timing is the main issue,’ Wardenaar continues. ‘This includes the distribution of protein intake across the day, such as 20 grams of protein per meal. Breakfast especially is a time when many sportspeople could lift their protein intake.’
There was also strikingly little variation of carbohydrate intake according to heavy and light training days. ‘Despite the fact that the more you train, the more you need,’ says Wardenaar. ‘Other studies have shown, for example, that football players who eat more carbohydrates run more kilometres during a match compared to those who eat less.’
Sportspeople who engage the services of a professional nutritionist also seem to perform better than those who do not. Wardenaar’s research incorporated data from endurance sports (rowing, swimming, skating, cycling, mid/long/ultra-distance running), team sports (football, volleyball, water polo, rugby, handball), and strength sports (track cycling, BMX, sprinting/bobsledding, sailing, gymnastics, and archery).
While conducting his study Wardenaar was involved in Eat2Move, an expertise centre working on optimum nutrition to promote performance and recovery in the recreational/elite sports and healthcare sectors. New insights lead directly to innovative industry programmes for the development of products and services. Eat2Move is an initiative of the Gelderse Vallei Nutrition Alliance (Wageningen University & Research and the Gelderse Vallei Hospital) and was developed in close collaboration with InnoSportNL, NOC*NSF (the Dutch Olympic Committee and Dutch Sports Federation), and the HAN University of Applied Sciences.
More information about Floris Wardenaar
Floris Wardenaar is a nutritionist and sports dietician. He completed his PhD at Wageningen University & Research alongside his job in the Sports and Exercise programme at HAN University of Applied Sciences, where he works in the field of sport, nutrition and health. He is also the leader of the Nutrition Team (Team Voeding) at NOC*NSF.