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Nutrition, Nitric Oxide, Protein, and Carbs

A study focused on the exploration of nutrition and its relationship with bouldering. An exploration of macronutrients and supplements.

Staying healthy during the pandemic is one thing, but strength gains amidst isolation will require proper nutrition and training. Though each are important by themselves, together, they can make for an exceptional athlete. A diet focused around strength gains, built around protein synthesis and general recovery can allow the climb er to gewt even more out of their sessions, simply by having the available nutrients when they are resting. It’s all pretty cool.

That said, nutrition and climbing have a bit of a rocky past. Historically, nutrition in climbing has not always been approached positively. Male and female climbers alike have pursued strength gains by reducing their Body Mass Index (BMI) to unhealthy levels ultimately creating opportunities for injury and other negative consequences. Climbing is a high-intensity sport that is hard on the body. Without ingesting the proper macronutrients, it is difficult to reach your full capacity as a climber. Enter, Nutritional Considerations for Bouldering.

Brennan Doyle at PanAm – photo by Daniel Gajda

The Study in Summary

This study was carried out by by Edward Smith, Ryan Storey, and Mayur Ranchordas in conjunction with Sheffield Hallam University back in 2017. It begins with a description of competition bouldering, their methodology, the energy systems of bouldering, and a description of climbing specific strength. It then moves into anthropometric characteristics, which we’ll discuss later, and macronutrients. The full publication can be found here.


For many anaerobic athletes, like boulderers, carbohydrates have been anecdotally considered poor for performance. However, the intake of 3-to-12 grams of carbs per kilogram of body weight per day is necessary to replace glycogen leveln Glycogen is important because it is a form of energy storage. For high-intensity sports similar to bouldering, around 5 grams per kilogram per day is considered sufficient.

This paper relays the importance of eating carbohydrates 1-4 hours before training to enhance oxidation and glycogen resynthesis. As bouldering does not rely on carbohydrates due to its short duration and high-intensity sport, 1 gram per kilogram before training should be enough to provide energy for the session.


You may have noticed athletes in other disciplines chugging protein shakes “for the gains,” and there is a reason for it. Protein is essential for muscle development. That said, nobody needs to drink ten shakes a day, but protein powder does have real benefits. Whey protein features even greater protein synthesis than soy and can really lend benefits to the developing climber. Ingesting around 20 grams of protein at a time can greatly improve your muscle recovery. You should not ingest more than that in a short period. Your body can only process so much protein in so short a period of time.

The reason the whey protein is such a good vehicle for the macronutrient is due to its high level of leucine. Leucine is an amino acid that helps with protein synthesis. This paper suggests protein intakes should fall between 1.4 and 2 grams per kilograms of body weight per day. To maximize strength gains and protein synthesis, protein intake should include high levels of leucine content.

Whey protein scoop.

Nitric Oxide:

This compound might be one of those secrets to training that is never really discussed. Nitric oxide is derived from dietary nitrate such as that found in Beetroot juice. Two hours following consumption, 25% of the nitrate is anaerobically converted to nitrite which is reduced to beneficial nitric oxide. Nitric oxide is radical. It stimulates improved muscle contractility, allowing the climber to grip with greater power. It also reduces the oxygen demand for an exercising muscle which would reduce the fatigue in the forearms during climbing. According to this paper, “Dietary nitrate supplementation could be a useful strategy for bouldering athletes as it has been found to enhance maximal power, contractile speed, and recovery time (Clifford et al., 2016; Rimer et al., 2016).” They go on to say, “An effective approach could be one 400mg dose of nitrate daily, followed by another dose 2-3 hours before competition.”

With all that said, Nutrition in climbing is a developing story that requires more research. In either case, health should come before everything else, and body positivity is essential to enjoying climbing. Nutritional science is exciting, however, and it is fun to imagine how strong we could become through eating alone.

Body Mass Index:

This paper presents data of the only two studies concerned with the BMI of elite boulderers at the time of its publication. Their data compares the characteristics of elite boulderers as: average height, weight and BMI values. For elite male boulderers, those values were 176.7 cm, 67.7 kg and 21.8 (BMI). For elite female boulderers, those values were 176 for males; 162 cm, 60.2 kg and 19.4 (BMI). BMI is calculated as kilograms per metre squared. These do not reflect the values of rock climbers, simply two sets of elite competition boulderers, one set of measurements taken from a competition where condition was at its highest.

Though these values are interesting from a scientific standpoint, the issue of low BMI has become recognized by governing bodies. In 2009, the Austrian Climbing Association introduced BMI restrictions, with a requirement of at least 17 for females and 18 for males to compete. The reason for this is that your body can suffer dramatically from not having enough nutrients. Light-weight does not always equate to health. The IFSC also expressed concern towards weight loss in climbing athletes and implemented BMI screening to disqualify athletes who refused to submit to BMI restrictions.