If Linus Pauling were still alive, he’d tell you that you need more vitamin C, whether you work out or not. He had ultimate faith in the power of vitamin C, especially for cold prevention. Under closer scrutiny, there’s really no proof that higher levels of vitamin C protect against colds, although studies are inconsistent on this. Still, don’t underestimate the importance of vitamin C – it has a number of important functions. So vital is this vitamin for health that some fitness experts think athletes could benefit from more than the recommended daily allowance of 75 milligrams daily for women and 90 milligrams for men. Is there any evidence this is true?
Vitamin C and Exercise: Do You Need More Vitamin C if You Do Vigorous Workouts?
Vitamin C is an antioxidant vitamin that helps protect cells against oxidative stress that comes from exposure to oxygen. That’s certainly a good thing – but not necessarily if you get it around the time of your workout. There’s some evidence that popping a vitamin C supplement or consuming antioxidants, especially in supplement form, before exercise interferes with some of the positive adaptations your body makes in response to exercise – adaptations that account for some of the health benefits of exercise.
It seems that the free radicals produced in response to strenuous exercise train your body to better deal with oxidative stress. At the same time, they activate signaling pathways that cause positive adaptations to occur in response to exercise. Seems your body has developed its own way to deal with oxidative stress during exercise and consuming more antioxidants may interfere with what your body does naturally.
One way exercise is beneficial is it boosts insulin sensitivity. Antioxidant supplements may block this response so you don’t get the full benefits. Although some studies suggest antioxidants don’t interfere with improvements in insulin sensitivity, most don’t show that getting more of these free radical fighters around the time of exercise speeds up recovery, reduces muscle soreness or has other measurable benefits.
Possible Benefits for Athletes Independent of Antioxidant Activity
Research does show that even marginal vitamin C deficiency can impact exercise performance. It can cause muscle weakness and fatigue that reduces strength and performance and makes workouts feel harder. It’s also vital for healthy tendons and joints. In addition, vitamin C helps to reduce cortisol release in response to stress or strenuous exercise. Cortisol has a catabolic effect on muscle tissue, increasing breakdown of the lean body mass you’ve worked so hard to build. Plus, vitamin C is beneficial for a healthy immune system. Long periods of endurance training can suppress your body’s ability to fight off colds and viruses. If you do long periods of endurance exercise, don’t skimp on the “C.” It keeps your immune system primed to fight off infection.
What Does This Mean?
It’s important to get enough vitamin C in your diet but there’s not a lot of evidence that taking vitamin C supplements will improve your performance or help you recover more quickly from a workout. In fact, taking a vitamin C or other antioxidant supplement before a workout could actually interfere with training adaptations.
If you eat a whole food diet that’s rich in fruits and vegetables, you should be able to get enough vitamin C through diet alone. Orange juice isn’t the only good source of vitamin C. Red peppers, strawberries, broccoli, kale, kiwi, cauliflower and even Brussels sprouts are all super rich in vitamin C. Eat plenty of these foods and you won’t have to worry about taking supplements.
It’s not clear whether consuming antioxidant-rich foods as opposed to supplements prior to exercise has any effect on training adaptations. Until more is known it’s best to eat foods high in antioxidants an hour or two after a workout, not right before you begin a training session.
Keep in mind that vitamin C is a water-soluble vitamin you can’t store in your body so you need to get enough every day. Load up on fresh produce to get your fair share of this essential vitamin. In most cases, it’s best to get vitamins naturally from food rather than from a supplement so you can benefit from all the other components in the food and the synergism they have with one another. Enjoy eating a vitamin C rich diet – but skip the supplements.
Sports Med. 2011 Dec 1;41(12):1043-69.
AJP – Endo May 1, 2011 vol. 300 no. 5 E761-E770
Int J Sports Med. 2001 Oct;22(7):537-43.
Am. J. Clin. Nutr. 57(2): 170-174, 1993.
J Sports Med Phys Fitness. 2006 Sep;46(3):462-7.
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