They found the best way to avoid unfavourable changes in the immune system during a post-workout recovery was consuming carbs during or immediately after the exercise.
In a paper published in the Journal of Applied Physiology, academics from Queensland University of Technology said there was intense interest in what athletes can do to recover faster from exercise.
“Among various nutritional strategies to counteract immune depression during exercise recovery, carbohydrates have proven the most effective. Ingesting carbohydrates during vigorous exercise may help, because carbohydrates maintain blood sugar levels,” stated Dr Jonathan Peake
The paper adds that carbohydrate supplementation during prolonged, intense exercise consistently reduces circulating cytokines, and the re-distribution of neutrophils, monocytes, natural killer cells and lymphocytes.
The researchers advise that most people only need carbohydrates during high-intensity or prolonged exercise of 90 minutes or more.
“Between 30 and 60 grams of carbohydrates every hour during exercise help to support normal immune function. Examples of carbohydrates that could be consumed during exercise include carbohydrate-containing fluids, gels and bars consisting of different carbohydrates such as glucose and fructose,” said co-author Oliver Neubauer.
The researchers also pointed to findings suggest that carbohydrates may help to diminish immune disturbances over consecutive days of exercise.
“These findings suggest beneficial effects of a timely carbohydrate supplementation (i.e., shortly before and/or during exercise) on immune responses to exercise. This may be particularly relevant with more prolonged and/or intense exercise protocols, and when the recovery duration between two consecutive exercisebouts is short,” states the paper.
However, evidence of other effective nutritional countermeasures to exercise-induced immune alterations is limited, they argue.
They accept that some data point towards the beneficial effects of quercetin supplementation on immune health after intense exercise, while they add other findings suggest an increased need for antioxidants during the first 24 hours of recovery from intense exercise lasting several hours.
“However, taken together, the present literature is not sufficiently robust to recommend supplementation with phytochemicals or antioxidants to prevent immune suppression and illness in athletes and exercising individuals,” they wrote.
“Athletes often take high doses of antioxidant/phytochemical supplements in the belief that this will reduce their risk of illness. However, high doses of antioxidant/phytochemical supplements can interfere with training adaptations. A natural diet rich in fruits, vegetables, whole grains and nuts delivers antioxidants and phytochemicals in physiologically effectiveamounts that are most likely sufficient to help maintain immune function following exercise and during exercise training,” they add.
Source: Journal of Applied Physiology
“Recovery of the immune system after exercise”
Authors: Jonathan M. Peake, et al