"The gluten inhibits that process and therefore the onset of muscle soreness is worse. The general ability to recover and retain that homeostatic state is compromised. Your threshold of work levels is lower and your recovery rate is higher and longer."

Everard would like to see more studies into the effects of gluten, which he believes could be at the heart of many modern illnesses.

"This is a very complex area and not fully understood in mainstream medicine, however there is a huge amount of research and evidence in this field," he said.

"I see the benefits of a gluten-free diet in my patients every day through clinical experience, but there still needs to be more research done so that this can become more mainstream -- especially in the world of sport."

Many studies focus solely on the benefits or otherwise of eliminating gluten, rather than taking into account other dietary elements.

"The question is -- is it actually gluten that is the problem or is it refined grains or grains in general?" says British nutritional therapist Kate Delmar-Morgan.

"Individuals wishing to go down this route should seek proper nutrition advice and be tested if possible."

There is also the issue that many gluten-free products are processed and contain high levels of added sugars and artificial additives.

"People will look at these products and think they are 'healthy' just because they are advertised as gluten-free," Delmar-Morgan says.

"However if people stick to a wholefoods diet -- i.e. fresh fish, meats, vegetables, fruit, nuts and seeds, wholegrains which do not contain gluten, and they try to cook from scratch as much as possible and have limited pre-prepared foods -- they can then avoid this problem."