Vitamin C and High Performace Sports | A “short” Summary

4 min readAug 19, 2020

Disclaimer: This article claims not to be of scientific basis, yet I tried to make it as unbiased, objective and scientifically correct as I could. Please feel free to correct me on any mistakes!

General health benefits of vitamin C supplementation

A range of studies has found the supplementation of vitamin C helpful in different areas, regarding the immune system. Stöhle & Hahn (2009) [1] discuss the effects of vitamin C and immune function, prefacing with the idea, that it may be helpful in the prevention and therapy of the common cold. Different cells of the immune system (t-cells & phagocytes, …) can accumulate the vitamin. When looking at the effects on the common cold, studies have found that there is a reduction in the duration, but not in severity or incidence.
Bendich & Langseth 2013 [2] look at safety concerns and effects on different kinds of diseases. The study lists 8 placebo-controlled, double-blind studies and 6 clinical trials in which up to 10,000 mg of vitamin C were consumed daily for up to 3 years. No risks in taking higher than RDA levels were found. The data in these studies suggest, that supplementing vitamin C in such dosages may lower the risk for cardiovascular disease and lowering blood pressure LDL oxidation and cardiovascular mortality.

Excercise-induced oxidative stress

Supplementing vitamin C under a performance aspect is often regarded to, as staying healthy to keep training, most often meaning shortening of the duration or even prevention of the common cold. As we have seen already, there are currently no scientific findings which back up this claim.
Looking at oxidative stress during phases of high-intensity exercise, bigger volume or increased work-load of other kinds, antioxidant supplementation (e.g. vitamins c & e) may limit the build-up of ROS.

On ROS

Reactive oxygen species build up within cells and organelles such as mitochondria, which is used for ATP (= used for muscle contraction, …) production. Excercise-induces ROS can have negative effects on an athletes body/performance in the form of muscle damage, immune dysfunction and fatigue.

Oxidative stress can accumulate from many different sources, not exercise-induced only. Schröder & Krutman (2004) [3] layout different environmental sources of possible build-up which may be contributing factors when looking at endurance training. UV-light from solar radiation may be a relevant factor when considering that elite endurance athletes train up to 7hrs per day outside in often warm climates. Nutrition and industrial pollution may also contribute to an increase in ROS, which all-together must be accounted for.

Effects on Performance

Gomez-Cabrera et al. (2008) [4] looked into possible hampered training-induced adaptions caused by oral administration of vitamin C. The study included 14 males (27–36yrs) and 24 male rats. Focusing on the human part of the study, five athletes were supplemented daily with 1g of vitamin C over a period of 8 weeks. The study found a significant attenuation in endurance capacity, which may result from reduced expression of key transcription factors involved in mitochondrial biogenesis.
Paulsen et al. (2014) [5] conducted a double-blind, randomised, controlled trial in which 54 men and women received either 1g of vitamin C and 235mg vitamin E or a placebo replacement daily for 11 weeks. During this supplementation period, the participants underwent a training program of 3–4 sessions per week (mostly running), which incorporated HIIT and steady (still 70-90% HRmax) training sessions. This study concludes that the supplementation of vitamin C & E did not affect the training-induced increases in VO2max and running performance in the 20m shuttle test. Although and interference on the muscular cellular level was found which indicate that antioxidant supplementation may be a factor in cell signalling in skeletal muscles. Also, these cellular result may impact physical performance markers under submaximal workloads.

Summary

Braakhuis (2012) [6] summarises 12 studies to find a possible answer on advising the supplementation of vitamin C in athletes. The conclusion suggests taking in a small dosage (0.2g/day) by eating fruits and vegetables to use the positive effects of antioxidant supplementation of ROS and exercise/environment-induced oxidative-stress. Going into higher dosages may only be beneficial in periods of 1–2 weeks, where increased stress levels are expected. Closing with the statement, that further research is required to give adequate advice and guidance on antioxidant supplementation and dosage (vitamin C in this case).

This might be the most accurate advice on whether supplementation might be beneficial for (elite) athletes, as it is shown to be a good antioxidant/supplement in the general population.

My take

I have tried to make this representation short, yet as accurate as possible, providing Wikipedia links to the most important terms and linking relevant studies down below.
But I am not a scientist, and this is obviously no scientific paper, hence why I want to close with a few of my thoughts on practical applications and supplements.

As I mentioned above, when it comes to supplementing vitamin C, athletes tend to use it, to aid their immune system to stay healthy and keep training. The scientific findings show, that this is most likely a misconception and there may be far more useful alternatives to vitamin C. Zinc, for example, is one of those. I will go into the supplementation of Zinc in another article here on medium, as I intend to use this platform for my own research into certain topics related to high-performance training, nutrition and recovery.