Study under review: A Placebo-Controlled Trial of Riboflavin for Enhancement of Ultramarathon Recovery
No one enjoys walking up the stairs after leg day. For most people, muscle pain is a simple nuisance, but it can be a tremendous limitation for performance athletes. Technically, post-exercise muscle pain is called delayed onset muscle soreness (DOMS). DOMS is noticeable within 24 hours of finishing a workout, but it tends to peak 24-72 hours afterward. The detrimental effectsPMID: of DOMS on athletic performance are well documented and include reduced joint range of motion, reduced strength and power output, and alteration of exercise technique to compensate for muscle soreness - all of which can increase the risk of injury.
Exercise-induced muscle damage and DOMS tend to be caused by novel stimuli, but this isn’t set in stone. Exercise duration and intensity are also important determinants. Several mechanisms have been proposed to contribute to DOMS, including damage to the muscle fibers and connective tissue and increased levels of inflammation and oxidative stress. Exercising for longer durations or at higher intensities, even when the exercise is familiar, can cause greater levels of physical damage to muscle fibers and connective tissue that lead to a more pronounced inflammatory response. The known roles of oxidative stress and inflammation in DOMS have led to many investigations into the use of antioxidant and anti-inflammatory foods and supplements. Some examples include vitamins C and E, polyphenols such as EGCG, carotenoids, and omega-3 fatty acids. Non-steroidal anti-inflammatory drugs (NSAIDs), particularly aspirin and ibuprofen, have also been investigated for their ability to affect DOMS.
Riboflavin, also known as vitamin B2, is an essential vitamin that has antioxidant properties. The RDA for riboflavin is set at 1.3 milligrams per day for adult men and 1.1 milligrams for adult women. There is no established upper limit for toxicity and deficiency (ariboflavinosis) is rare due to riboflavin’s widespread abundance in food. It operates primarily through two derivatives: flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which function as coenzymes for a wide variety of oxidation-reduction reactions necessary for life. The redox chemistry of riboflavin is depicted in Figure 1.
Several studies have suggested that physical activity may increase riboflavin requirements. However, early supplementation studies reported that riboflavin supplementation failed to improve athletic performance in women, children, and elite swimmers. A nine-month randomized crossover trial in competitive long-distance runners found no benefit of multivitamin supplementation (providing 60 milligrams of riboflavin) on athletic performance despite a significant increase in riboflavin status.
To date, the research into riboflavin supplementation and athletics has focused on chronic performance adaptations. Whether riboflavin supplementation might provide a protective role or enhanced recovery from exercise-induced muscle damage and DOMS is unknown. The study under review investigated whether the acute ingestion of a high-dose riboflavin supplement would reduce muscle pain and soreness during and after the completion of an ultramarathon, as well as improve functional recovery after the event.
Exercise-induced muscle damage and delayed-onset muscle soreness (DOMS) impair athletic performance and increase the risk for injury. Inflammation and oxidative stress are known to play a role in these detrimental effects. Riboflavin (vitamin B2) is an essential vitamin that functions as an antioxidant and its requirements may be increased with regular exercise training. The study under review investigated the effects of high-dose riboflavin supplementation on muscle pain and soreness during and after an ultramarathon, as well as its effects on functional recovery after the event.
Other Articles in Issue #37 (November 2017)
Interview: Matt Stranberg, MA, RD, CSCS
In this interview, we chat with Matt about the utility of personal genomics for nutrition, how to keep up with nutrition research, what leads to successful dieting, and much more.
Interview: Mike Howard
Personal trainer and mindset performance coach Mike Howard shares his wisdom on how to stick with goals, his thoughts on Whole30, and more.
Aspartic acid on trial: no, it doesn’t boost testosterone
The evidence for D-aspartic acid boosting testosterone has been mixed. This trial used a high dose for a longer time to help settle the matter.
Vitamin D for athletes
Even athletes are subject to vitamin D deficiency. How much do they need to reach sufficiency, and does vitamin D supplementation have an effect on performance?
A whole (grain) in the evidence
Whole grain is thought to be heart healthy, mainly because of observational evidence. Are randomized controlled trials consistent with this recommendation?
Can magnesium supplementation reduce cardiovascular disease risk factors in people with diabetes?
Observational, mechanistic, and animal evidence suggests that magnesium deficiency could raise the risk of CVD and diabetes. Could supplementation help?
Is exercise enough to improve the metabolic syndrome?
Diet and exercise combined can make an impact on factors of the metabolic syndrome. But could exercise by itself be enough to make a meaningful improvement?