GOAL: To give rock climbers practical sport nutrition for at the gym or at the crag.


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Sep 22, 2008

Two Climbers and their Bag of Rice: My nutrition research on rock climbing and oxidative stress

It’s amazing where life can take you…

Several years ago I started working in a nutrition research lab at the University of Manitoba as a summer student. The research I was hired on to do had absolutely NOTHING to do with sports nutrition, athletes or rock climbing. I was new to nutrition and just wanted some experience in the field. At that same time, two crazy guys from my rock climbing gym were planning a month-long rock climbing/camping trip out to a local crag. Being the typical poor university students they were, they wanted to spend as little money as possible. Knowing they could not cut down on the costs of gas, camping equipment or climbing gear, they aimed to spend as little money as possible on food. So, they went to the grocery store and purchased the largest, cheapest bag of short-grain white rice they could find. They also bought some tuna, flour for making bannock and those dry soup noodles you just need to add water to, expecting that this was all they needed for the month (does this sound familiar to any of you?).

I was no nutrition expert at that time, but I knew something was missing in their food plan. When I next met with my nutrition research supervisor, I told her about these two guys and what they planned to eat for an entire month. I asked “What will happen? What are they doing to themselves?” My supervisor pondered a quick moment and responded very excitedly “I don’t know…Let’s study them!!”

After much literary research and ethics approval pages later, we came up with this rock climbing research study. To my knowledge it is the first nutrition research study on rock climbers, and I am proud to say that it is being published in the Journal of Applied Physiology, Nutrition, and Metabolism!

The Study

Our subjects were two males in their early 20s who were going climbing and camping for 5 weeks. They chose entirely what and how much they ate and climbed; we just observed

Considering their food plan, we expected that they 1) wouldn’t eat enough calories to match their level of exercise; 2) would lose body weight and body fat, and; 3) would have oxidative stress.

What is oxidative stress and why should anyone care about it?

In the athlete, oxidative stress can hurt performance.

Oxidative stress happens when certain hyperactive molecules in the body become too many that our body can’t handle them. These molecules, known as free radicals, can do damage to our cells and tissues by affecting our DNA, our proteins and the lipid molecules that make up our cell walls. One example is superoxide anion, which is an oxygen molecule with one unpaired electron.

Small amounts of free radicals are actually quite helpful. For example, a little bit of free radical production in the muscles help them to contract. However, when too many free radicals are made due to overtraining or not enough rest, oxidative stress occurs and the free radicals can attack our muscle cells, which may cause them to fatigue. This may contribute to overuse injuries in overtrained athletes.

To keep free radicals at a manageable level, the body uses antioxidants to get rid of excess free radicals. These can be protein enzymes that are made by the body, or they can be vitamins and minerals (such as vitamins A, C and E and zinc) that we need to eat. Athletes in general produce more free radicals then your average day Joe and therefore athletes need to eat higher amounts of vitamins and minerals as well. Studies show athletes who don’t get enough antioxidants in their diet have a higher perceived exertion during exercise (exercise feels harder for them).

Knowing that these two climbers were depending mostly on short-grain white rice (which has very little vitamins and minerals), and that climbing is a high-intensity sport, we assumed that they would have oxidative stress at some point during their 5-week trip.

How did we study them?

Before they left for their trip, we had the two climbers fill out diet and activity journals. We measured their body weight, body fat, skinfolds, and took a blood test. Once a week while they were out climbing/camping, a skilled technician (me!) would drive out to the campsite and collect all of the same information, and do all of the same tests. These were repeated again when they got back from their trip.

What did we find?

We had assumed that they wouldn’t eat enough calories to match their exercise level. We were right! In fact, they only ate about 2000 kilocalories per day, when they needed 3200 kilocalories…that’s 40% less then they needed! On top of that, they did not get enough carbohydrate, protein, vitamins A, C, D, E, B2 and calcium and zinc.

They did in fact lose body weight; about 6% of the weight they had before they left. They also lost 16% of their initial body fat mass. But, weight loss is never just fat…they did lose fat free mass as well (which is made of bone, muscle, cartilage, fluid, etc), though we were not able to measure muscle mass directly.

We had assumed they would experience oxidative stress. We were right again! In their blood, we measured a molecule that usually isn’t there unless oxidative stress is occurring. The amount of this molecule (known as F2-isoprostanes) continuously increased in their blood from the time they left to the time they got back.

We also measured the antioxidants in their blood. Vitamin C dropped very low. Antioxidant protein enzymes (such as superoxide dismutase and glutathione peroxidase) also dropped in the last 2 weeks of their trip, meaning they would not have helped protect against the oxidative stress.

To summarize the study findings, these two crazy guys:

  • Lost body weight, including fat and fat free mass (bone, muscle, etc)

  • Did not eat enough calories, carbohydrates, protein, vitamins A, C, D, E, B2 and calcium and zinc

  • Had oxidative stress while their antioxidants decreased

What does this mean?

It’s important to keep in mind that this study was only on 2 people! That means that although these results are really cool and show the need to do more studies on rock climbers, we can’t make too many conclusions from this study alone about what rock climbers should eat.

We were also not able to measure performance in our two rock climbers. So we can’t say for sure whether their diet combined with their outdoor training hurt their climbing ability. However, based on their journals and their comments throughout the study:

  • They developed and suffered joint pains and overuse injuries

  • Their skin didn’t heal as quickly

There is no doubt that oxidative stress happened in these two guys, and that not enough food energy and vitamins and minerals were consumed.

Not getting enough food energy (also known as energy restriction) has been shown in lots of studies to hurt performance. Energy restriction:

  • Decreases endurance

  • Decreases strength and stamina

  • Slows wound healing

  • Decreases lean muscle

Consuming enough antioxidants through food or supplement has been shown to combat oxidative stress in athletes, which may help performance.

Had these two guys consumed enough food energy and vitamins and minerals, they may have had less overuse injuries and joint pains, their skin might have healed better and their climbing performance may have been better. Although, we can’t conclude this here and more studies need to be done to see if this is true.

Practical Tips

The study that I did may have more opened the door for more studies in our sport then it did give climbers precise nutrition information. However, the concepts learned here are the same in all sports, and have been shown in all sports to improve performance:

  • A prolonged low calorie diet won’t help you climb better

  • Athletes, including climbers, have higher needs for vitamins and minerals

You can get enough vitamins and minerals, including antioxidants, in foods. Studies have proven that oxidative stress can be combated in athletes who eat foods high in antioxidants.

What foods are high in antioxidants?

Dark and brightly coloured vegetables are generally high in vitamins and minerals. Here are some select choices:

  • Apricots

Vitamin A

  • Sweet potato (Yam)

Vitamin A

  • Carrots

Vitamin A

  • Turkey

Vitamin A

  • Cantaloupe

Vitamin A, C

  • Brussel sprouts

Vitamin A, C

  • Spinach

Vitamin A, C

  • Tomato

Vitamin A, C

  • Strawberries

Vitamin C

  • Grapefruit

Vitamin C

  • Broccoli

Vitamin C

  • Kale

Vitamin C

  • Bell peppers

Vitamin C

  • Oranges

Vitamin C

  • Almonds, Peanuts

Vitamin E

  • Sunflower, Canola, Corn, Soybean, Olive oil

Vitamin E

  • Asparagus

Vitamin E

It’s easy to fit these into your everyday foods:

  • Cut fruit into cereal and yogurts for breakfast or as a snack

  • Peel or chop carrots or broccoli into tomato soup, pasta sauce or burrito/taco mix

  • Mix spinach into salads or put into sandwiches

  • Chew on bell pepper sticks as a snack

  • Experiment making your own pizzas with as many vegetable and fruit toppings and combinations as you like

  • Make your own salad dressing by mixing ¾ C of oil with ¼ C vinegar and chopped herbs (dill, basil, rosemary, paprika, mustard, etc)

What about supplements?

Studies have shown antioxidant supplements (usually Vitamins A, C and E) reduce oxidative stress in athletes who already have a low antioxidant diet. In athletes who have a well-planned diet, supplements don’t seem to have any effect.

When outdoor climbing, fresh food and a way to preserve the food is not always possible. In those cases, we probably don’t get enough vitamins and minerals in the diet, so a supplement could be helpful. Taking supplements while on a climbing/camping trip can be part of a well-planned diet, and supplements are generally safe in the adult population.

  • A multi-vitamin can provide the extras you need with the convenience of having to take just one pill a day.

  • Chose a supplement that is a brand name, as supplements are not regulated by law: unlike medications, what it says on the supplement bottle may NOT be exactly what’s in the pill. A brand name company has more to lose when it comes to integrity of their product, and so is more reliable.

To summarize supplementation:

  • When you are at home and have access to fresh foods, ALWAYS count on FOOD FIRST. For most, you can get all you need through food and should first work on optimizing your food plan.

  • Supplements are to help the food plan. Add on supplements to optimize your food plan or when you can’t meet certain goals through food, such as in outdoor climbing/camping situations.

  • Choose brand name supplements. Until further research, a multivitamin may be good enough to meet your antioxidant needs when outdoors.

Stay Tuned!

I am conducting another study and need your help!

Stay tuned to this website to find out how you can participate in an online survey!

Any questions?



Clarkson, P., Thompson, H. (2000). Antioxidants: What role do they play in physical activity and health? Am J Clin Nutr, 72(suppl), 637S-646S.

Finaud, J., Lac, G., Filaire, E. (2006). Oxidative stress: Relationship with exercise and training. Sports Med, 36(4), 327-358.

Sen, C. (2001). Antioxidants in Exercise Nutrition. Sports Med, 31(13), 891-908.

Watson, T., Callister, R., Taylor, R., Sibbritt, D., MacDonald-Wicks, L., Garg, M. (2005) Antioxidant restriction and oxidative stress in short-duration exhaustive exercise. Med Sci Sports Exerc, 37(1), 63-71.