Podcast: Antioxidants for preventing and reducing muscle soreness after exercise

A variety of approaches have been suggested for reducing muscle soreness after exercise, one of which is to use antioxidant supplements. A new Cochrane Review from December 2017 brought together the evidence from the relevant research and lead author, Mayur Ranchordas from Sheffield Hallam University in the UK, tells us what they found in this podcast.

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John: Hello, I'm John Hilton, editor in the Cochrane Editorial and Methods department. A variety of approaches have been suggested for reducing muscle soreness after exercise, one of which is to use antioxidant supplements. A new Cochrane Review from December 2017 brought together the evidence from the relevant research and lead author, Mayur Ranchordas from Sheffield Hallam University in the UK, tells us what they found in this podcast.

Mayur: Although we know that physical activity is beneficial to health, it can cause something called oxidative stress which depletes the body’s antioxidant defences and increase the rate of free radical production. Moreover, unaccustomed, eccentric or exhaustive exercise may contribute to reduced antioxidant defences causing exercise-induced muscle damage and muscle soreness. It’s been suggested that dietary antioxidants can counteract oxidative stress and help athletes when returning to training from injury and make it easier for sedentary and older individuals to recover from unaccustomed physical activity.
Therefore, taking dietary antioxidants in the form of supplements such as tablets, capsules, powders or even in antioxidant-enriched foods in doses up to 10 times the recommended daily amounts has been proposed as a way to prevent or reduce muscle soreness after exercise. However, as I’ll outline, the findings of our review do not support this. We had also wanted to see what the evidence says about side effects but few studies reported on these, although two of the studies found that some people who took antioxidants experienced gastrointestinal distress – such as diarrhoea, indigestion and bloating.
Overall, we included 50 randomised trials with a total of nearly 1100 participants. The tested antioxidants varied from vitamin supplements such as C and E, whole foods such as blueberry smoothies and pomegranate juice, tea and extracts such as curcumin which is found in the spice, turmeric. The doses were higher than the recommended daily amounts and, although the types of exercise varied, there was always enough to cause muscle soreness. Most of the studies had features that carried a high risk of bias because of selective reporting and poorly described allocation concealment, which further limits our confidence in the reliability of their findings.
In summary, we found that antioxidant supplementation may very slightly reduce muscle soreness in the first three days after exercise, but these reductions were so small that they were unlikely to make any difference. On top of our findings, studies have recently emerged showing that chronic antioxidant supplementation may actually be counterproductive. The supplements may delay healing and recovery from exercise, hinder adaptations to training, and may even increase mortality.
Taking all of this into consideration, our main take home message is to steer clear of antioxidant supplements and use your money for other things. Try and move more, exercise regularly, and eat a balanced diet that includes at least five portions of rainbow coloured fruits and vegetables every day. For now at least, there is no quick fix to easing muscle soreness after exercise and, in fact, muscle soreness may well be an important part of the recovery process and can help to make your muscles stronger and bigger over time.

John: If you would like to look deeper into the evidence in Mayur’s review, it’s easy to find it online. Just go Cochrane Library dot com and search 'antioxidants and muscle soreness'.

John: “A variety of approaches have been suggested for reducing muscle soreness after exercise, one of which is to use antioxidant supplements. A new Cochrane Review from December 2017 brought together the evidence from the relevant research and lead author, Mayur Ranchordas from Sheffield Hallam University in the UK, tells us what they found in this podcast”Mayur: “Although we know that physical activity is beneficial to health, it can cause something called oxidative stress which depletes the body’s antioxidant defences and increase the rate of free radical production. Moreover, unaccustomed, eccentric or exhaustive exercise may contribute to reduced antioxidant defences causing exercise-induced muscle damage and muscle soreness. It’s been suggested that dietary antioxidants can counteract oxidative stress and help athletes when returning to training from injury and make it easier for sedentary and older individuals to recover from unaccustomed physical activity.Therefore, taking dietary antioxidants in the form of supplements such as tablets, capsules, powders or even in antioxidant-enriched foods in doses up to 10 times the recommended daily amounts has been proposed as a way to prevent or reduce muscle soreness after exercise. However, as I’ll outline, the findings of our review do not support this. We had also wanted to see what the evidence says about side effects but few studies reported on these, although two of the studies found that some people who took antioxidants experienced gastrointestinal distress – such as diarrhoea, indigestion and bloating.Overall, we included 50 randomised trials with a total of nearly 1100 participants. The tested antioxidants varied from vitamin supplements such as C and E, whole foods such as blueberry smoothies and pomegranate juice, tea and extracts such as curcumin which is found in the spice, turmeric. The doses were higher than the recommended daily amounts and, although the types of exercise varied, there was always enough to cause muscle soreness. Most of the studies had features that carried a high risk of bias because of selective reporting and poorly described allocation concealment, which further limits our confidence in the reliability of their findings.In summary, we found that antioxidant supplementation may very slightly reduce muscle soreness in the first three days after exercise, but these reductions were so small that they were unlikely to make any difference. On top of our findings, studies have recently emerged showing that chronic antioxidant supplementation may actually be counterproductive. The supplements may delay healing and recovery from exercise, hinder adaptations to training, and may even increase mortality.Taking all of this into consideration, our main take home message is to steer clear of antioxidant supplements and use your money for other things. Try and move more, exercise regularly, and eat a balanced diet that includes at least five portions of rainbow coloured fruits and vegetables every day. For now at least, there is no quick fix to easing muscle soreness after exercise and, in fact, muscle soreness may well be an important part of the recovery process and can help to make your muscles stronger and bigger over time.”John: “If you would like to look deeper into the evidence in Mayur’s review, it’s easy to find it online. Just go Cochrane Library dot com and search ‘antioxidants and muscle soreness

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