Marisa Michael, MSc, RDN, CSSD is a board-certified specialist in sports dietetics and author of Nutrition for Climbers: Fuel for the Send. She serves on the USA Climbing medical committee and has a private practice in Portland, Oregon. Find her online at nutritionforclimbers.com or on Instagram @realnutritiondietitian for nutrition coaching, workshops, and writing services.

Antioxidants seem like a trendy buzzword. It’s one of those things you think should get in your diet, but you only vaguely know how and what the heck they are, let alone what they are supposed to do for your body. Read on to demystify antioxidants and what they can do for you as a climber.

What is an antioxidant?  These are components found in food that help neutralize free radicals in your cells. Free radicals are potentially harmful compounds that, if levels are too high, increase risk for heart disease, cancer, diabetes, and inflammation. Free radicals cannot be entirely avoided. Your body produces them during normal processes such as the immune system fighting an infection.

Exercise such as you do for climbing produces free radicals, so hitting the fingerboard or doing big wall sessions is a double-edged sword. Other sources of this oxidative stress include air pollution, alcohol intake, radiation, and excessive intakes of vitamin C and vitamin E, which is ironic since these two vitamins are antioxidants.

What are some common antioxidants? Your body has its own system to produce antioxidants that fight free radicals. Common dietary and supplement sources include vitamin C, vitamin E, coenzyme Q10, flavonoids, polyphenols, and carotenoids. You may have heard of these terms but don’t quite know what they are and how to get them in your diet.

What are some food sources of antioxidants? Fruits and vegetables are packed with antioxidants. Whole grains, coffee, and legumes contain antioxidants. Eating food that is fresh or frozen (because the produce is frozen right at harvest) is your best bet, as produce loses nutrients after harvest. The longer produce is stored or cooked,  the more nutrients are lost. Cooking vegetables for the shortest amount of time will help preserve antioxidants that could otherwise be destroyed by heating. Choose steaming or stir-frying rather than boiling or slow cooking, and eat raw fruit.

Some spices also help contribute to your antioxidant intake. Cinnamon, turmeric, sage, thyme, black pepper, and ginger all have high antioxidative power. 

What can they do for me as a climber? Antioxidants can contribute to overall health, decreased muscle soreness, and decreased inflammation. Tart cherry juice, full of antioxidants, has been shown in some studies to decrease muscle soreness. Try 12 ounces at bedtime after a particularly grueling session.

Can I go overboard with antioxidants? Yes! By sticking with food sources rather than supplements and pills, you will get a wide variety of nutrients and antioxidants without the worry of overdosing. High doses of vitamin C can lead to diarrhea, kidney stones, and iron overload. High doses of vitamin A can lead to joint and bone pain, hair loss, and liver damage. Vitamin D toxicity can result in high blood calcium, constipation, and kidney damage. In general, don’t take a supplement unless you have a known deficiency and are directed by a doctor to do so.

If you’re tempted to take an antioxidant supplement just because it sounds like a good idea, Caitlin Holmes, Certified Nutrition Specialist, warns, “Unfortunately, antioxidants aren’t site-specific, meaning that we can’t definitively say whether taking them is producing the result we want.”

Consider this: An equivocal but growing body of evidence suggests that taking an antioxidant supplement can blunt training adaptations. (Merry & Ristow, 2016, Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training?, J Physiol, 594(18): 5135-5147). This is because exercise produces free radicals that act as signaling molecules for your body to adapt to the training load. Some free radicals are helpful—they tell your body that it’s under stress and signal it to adapt. It helps with both skeletal muscle and cardiovascular fitness.

Holmes explains, “We don’t understand enough about antioxidants, their mechanisms of action, or how they might impact other reactions in the body yet. Taking antioxidants may actually turn off some important signaling within the body.”

Don’t undermine your hard climbing sessions by taking an antioxidant supplement, unless it is specifically warranted and directed by your doctor (such as a micronutrient deficiency). Just get what you need from food.