Skip to content
Skip to content
Muscle & StrengthHub

Nutrition5 min read

Antioxidants and muscle growth: can vitamin C and E blunt your gains?

Hard training produces reactive oxygen species, often called free radicals. They sound harmful, so taking antioxidant supplements to mop them up seems sensible. But these molecules are also signals that tell your muscles to adapt, and several trials found high-dose vitamin C and E reduced some of the benefits of training.

By Updated

Share this guide

A muscular man at a gym café table holding an orange beside a bowl of berries and a pill bottle.

The short answer

High-dose antioxidant supplements can blunt some training gains. In trials, about 1,000 mg of vitamin C with vitamin E reduced markers of endurance adaptation (Paulsen et al., 2014) and reduced lean mass gains from strength training in older men (Bjørnsen et al., 2016). Antioxidants from fruit and vegetables have not shown this problem.

  • Vitamin C and E reduced cellular endurance adaptations, though fitness gains were similar (Paulsen et al., 2014).
  • In older men, vitamin C and E reduced lean mass gains from strength training (Bjørnsen et al., 2016).

Why antioxidants can blunt training adaptation

Vitamin C and muscle growth

An earlier trial found 1 g of vitamin C a day reduced signals for mitochondrial growth (Gomez-Cabrera et al., 2008). Results in young lifters are less consistent, so the safest reading is that high doses bring a risk and no clear benefit.

Do fruit and vegetables blunt gains?

No trial has shown that a normal diet rich in fruit and vegetables blunts training. Foods give much smaller amounts alongside fibre and other nutrients. Keep eating them.

Vitamin C, vitamin E and your workouts: what to do

  • Skip daily high-dose vitamin C and E supplements if your goal is muscle or fitness.
  • Eat fruit and vegetables freely.
  • Put your effort into training, protein and sleep, which have strong evidence.

Check any supplement's evidence group with the supplement evidence checker.

People also ask

Should I stop taking vitamin C after workouts?

There is no performance reason to take high doses. Normal amounts from food are fine.

Does tart cherry juice blunt gains?

It is less studied. Using high-dose antioxidants every day carries the same theoretical risk, so save them for short recovery periods if at all.

Do antioxidants help muscle soreness?

Some studies show small effects on soreness, but reducing soreness is not the same as better long-term gains.

Is a multivitamin a problem?

Most multivitamins contain far less vitamin C and E than the doses used in these trials.

Was this guide helpful?

Scientific References & Evidence

  1. Bjørnsen, T., Salvesen, S., Berntsen, S., Hetlelid, K.J., Stea, T.H., Lohne-Seiler, H., Rohde, G., Haraldstad, K., Raastad, T., Køpp, U., Haugeberg, G., Mansoor, M.A., Bastani, N.E., Blomhoff, R., Stølevik, S.B., Seynnes, O.R. and Paulsen, G. (2016) 'Vitamin C and E supplementation blunts increases in total lean body mass in elderly men after strength training', Scandinavian Journal of Medicine & Science in Sports, 26(7), pp. 755-763. doi: 10.1111/sms.12506. Available at: https://doi.org/10.1111/sms.12506
  2. Gomez-Cabrera, M.C., Domenech, E., Romagnoli, M., Arduini, A., Borras, C., Pallardo, F.V., Sastre, J. and Viña, J. (2008) 'Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance', American Journal of Clinical Nutrition, 87(1), pp. 142-149. doi: 10.1093/ajcn/87.1.142. Available at: https://doi.org/10.1093/ajcn/87.1.142
  3. Paulsen, G., Cumming, K.T., Holden, G., Hallén, J., Rønnestad, B.R., Sveen, O., Skaug, A., Paur, I., Bastani, N.E., Østgaard, H.N., Buer, C., Midttun, M., Freuchen, F., Wiig, H., Ulseth, E.T., Garthe, I., Blomhoff, R., Benestad, H.B. and Raastad, T. (2014) 'Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans', The Journal of Physiology, 592(8), pp. 1887-1901. doi: 10.1113/jphysiol.2013.267419. Available at: https://doi.org/10.1113/jphysiol.2013.267419
  4. Ristow, M., Zarse, K., Oberbach, A., Klöting, N., Birringer, M., Kiehntopf, M., Stumvoll, M., Kahn, C.R. and Blüher, M. (2009) 'Antioxidants prevent health-promoting effects of physical exercise in humans', Proceedings of the National Academy of Sciences, 106(21), pp. 8665-8670. doi: 10.1073/pnas.0903485106. Available at: https://doi.org/10.1073/pnas.0903485106

Read next

Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to your doctor or a health professional.