While the jury is still out on whether or not you should take supplements for your general, overall wellbeing, a lot of people hail the benefits of taking such pills for fitness and athletic performance. Whether you take little gels with you on your long runs, or pump up with a protein shake after long strength-training workouts, fitness experts and enthusiasts believe in the wellness benefits of supplementation – which may make a new study quite a hard pill to swallow. Researchers in Norway have suggested that, if you are an endurance athlete, taking some types of vitamin supplement may make it harder to train for big events like marathons.
The findings of the study, which were published in The Journal of Physiology, led the researchers to conclude that you should use vitamins C and E with caution as they may “blunt” the way your muscles respond to exercise. That said, other leading experts have questioned the research, as the 11-week trial results revealed that actual athletic performance was not affected. The team of researchers at the Norwegian School of Sport Sciences in Oslo argued vitamin supplements were readily taken and available, but they did admit they were unsure if they affected athletic ability.
The trial went on for 11 weeks and, during this time, the 54 participants were given either 1,000mg of vitamin C plus 235mg vitamin E or a sugar pill and trained up to four times per week. The participants were given a beep test – in which you run faster and faster between two points 20m apart – but there was no difference in their performance during this test. The blood samples and tissue biopsies, on the other hand, suggested there were differences developing inside the muscle. Your muscle cells gain energy from lots of internal tiny mitochondria, and taking the supplements seemed to cause the participants to produce fewer extra mitochondria to cope with the increasing demands placed on the muscle.
Researcher Dr Goran Paulsen commented, ‘Our results show that vitamin C and E supplements blunted the endurance-training-induced increase of mitochondrial proteins, which are needed to improve muscular endurance. Our results indicate that high dosages of vitamin C and E, as commonly found in supplements, should be used with caution, especially if you are undertaking endurance training.’ However, Mike Gleeson, a professor of exercise biochemistry at Loughborough University, was less than convinced by the study results. According to Gleeson, the biggest factor in performance is actually how fast your heart and lungs can get oxygen to your muscles, not mitochondria. He added that the lack of a difference in athletic performance ‘makes it difficult to interpret,’ noting ‘The bottom line is studies show changes in the ability to adapt to exercise could be impaired by high-dose vitamins, but until there are studies showing them affecting athletic performance people shouldn’t be worried.’
Dr Emma Derbyshire, from the industry-backed Health Supplements Information Service, commented that some studies had shown a benefit. ‘In a four-week randomised controlled trial evaluating vitamin C and E supplementation among female athletes, supplementation reduced markers of oxidative stress compared with a placebo tablet and reduced muscle damage markers associated with aerobic exercise,’ she said. ‘This latest study is essentially preliminary and the research findings would need to be re-assessed in further work. Eating as healthy a diet as possible is very important for sports people and athletes. However, if they have a hectic training schedule, particularly for those doing endurance training who are not able to eat as well as they should, a multivitamin and mineral supplement provides a method of ensuring that the intakes of these essential nutrients, including vitamin C and E, follow recommended guidelines.’
