Thought I’d put together a short-list of ergogenic aids (supplements) that are actually useful for climbing.
Firstly, unless you are at the top of the game, a supplement with a 1 or 2% increase in performance is not going to be noticeable. That’s because, if you are climbing a 50m route, that supplement may get you 1m higher. There are many easier ways to achieve that than taking an exact amount of a supplement for many weeks that may have adverse side effects and can be expensive.
This post won’t go into the biochemistry of why the sports nutrition supplement can help your rock climbing performance. But that can be looked up in many textbooks or as information that I provide as part of my performance sports nutrition coaching programs.

Author on Over the Moon, LPT
So, here is my list, kind of in order of importance, of things that would have a meaningful performance nutrition benefit on rock climbing and bouldering:
- Carbohydrates:
These are the preferred fuel for your muscles. It can be stored locally in the muscle in the form of glycogen for easy and fast usage during climbing. Carbohydrate molecules contain oxygen, which can be used in oxidation for ATP creation. During training/climbing/bouldering blood glucose (carbohydrates) comes from the gut, which comes from eating carbohydrate. In this state, your muscles will preferentially use glucose over fats even at low heart rates. Carbs cause an increase in insulin (anabolic hormone) and reduce the circulation of glucagon (a fat/muscle breakdown hormone). If you are in the business of building muscle as part of adaptations to training stimulus, then insulin is a very valuable anabolic hormone.
My thesis for my Master’s degree in Nutrition and Exercise Science focused on the fuels used during Bouldering competitions. I found that the average RER during a 5-minute bout of bouldering at max level as about 1.0. This means that on average the body was burning carbohydrate. At the start of the round, realistically it would have been a blend of fats and carbs (RER = 0.85), then very quickly raising to pure carbs in the active muscles (RER = 1.0), then in max performance, the forearms will have been using phosphocreatine too (RER = 1.10).
How much to eat and when?
I tend to advise that people eat about 1.0-1.6 grams of protein per kilogram of body weight. Each gram of protein is worth 4 kcals. Once I have calculated the protein intake, I divide the remaining intake of calories for the day by 2. That’s how many carbs I suggest. Therefore a 70kg person, training hard and climbing every day, requires the nutrition of about 100g protein, which is 400 kcal. If they are aiming to eat 2500 kcal per day, then 2100 kcal remain for fats and carbs, I suggest 1050g for carbohydrates, which is about 265g per day. That would leave 115g for fats. This is obviously flexible, and for someone training hard, I may up the carbs and lower the fats. For someone in a very sedentary job, I would lower the calories and protein.
During intensive exercise, ie road biking, a person’s body can absorb about 60g glucose and a further 12g fructose per hour. That’s 280 kcal per hour from carbohydrates. Any more than this cannot be absorbed and therefore passes lower into your gut and can cause big problems with the bacteria, leaky-gut syndrome, stomach cramps and diarrhoea. This is often found by people smashing energy gels on an empty stomach, they are high in fructose and pass quickly through the gut.
So, before and during climbing it makes sense to have a ready supply of blood glucose for the muscles to continue to utilise once the local sources of glycogen are depleted. I, therefore, advise regularly eating at the crag or boulders throughout the session.
Recovery
The enzymes that breakdown and buildup glycogen in the muscles are activated during muscle usage and at certain temperatures with the blood flow. For climbing the forearm flexors are the ones to power-out after a few attempts at a redpoint, or after a campus session, or an hour of training. This lack of ability to continue putting out power has a multitude of reasons, but a lack of local energy supply is a key reason. To recover from this, it is best to take the opportunity to use the enzymes that are still active to rebuild and replenish the used glycogen (and intramuscular lipids too). The enzymes stay active for about 45-60 minutes after exercise. Absorption of carbs takes about 15 minutes. Therefore, I would encourage clients to eat carbohydrate immediately after training for about 45 minutes, aiming to eat about 70g throughout that period. This could be honey, Haribo, bananas, dried fruits, or a sugary sports drink. Your muscles don’t care where the glucose/fructose molecules started out.
If you get the recovery carbs in within about an hour, it is sometimes possible to completely recover the muscle glycogen within 24 hours. If you wait longer, it can take up to 5 days to recover that glycogen back to the original state.
- Creatine
I would recommend climbers to take about 0.035g per kilo lean body mass per day. Or about 0.03g per kilo per day. This amount has been shown to have some performance benefits without a significant increase in weight (from water retention). I would not advise doing a loading phase as prescribed on most sports nutrition creatine packaging. Creatine benefits are fairly complicated to explain, but basically, it boosts local reserves of creatine phosphate in the muscles which are used to donate a phosphate and make adenosine-triphosphate, energy for muscle contractions. This can potentially give a few per cent to max power style performance. Holding a sharp crimp, or pulling through a big move. This will not help endurance in any way. It is one of the most well researched performance-enhancing nutrition aids on the market, most high-level sportspeople use creatine.
- Vitamin D
Most people in the UK are deficient in vitamin D at some point of the year. I wrote another blog on this to do with boosting the immune system. When Vitamin D deficiency is corrected there are huge neuro-muscular gains to be made, the scientific evidence comes from leg squat strength and 10m sprint times. Given that most climbers train indoors all year round, and don’t get out to crags during the winter, I recommend taking a Vit D supplement from September to April.
- Caffeine
This is another very well studied performance-enhancing ‘drug’, that is legal. Most high performing athletes also take caffeine. If you can handle the side effects, difficulty sleeping, anxiety, stomach ache, jitters, then this is a very worthwhile aid. The best evidence suggests fairly high doses (3mg per kilo), about 45 minutes before exercise. I don’t think that’s a good idea for trad onsights of dangerous routes. I think your feet would be dancing all over the holds. But potentially for redpoints, hard boulders. The performance effects are actually very high (around 5%) for aerobic and anaerobic activities. Given the nature of climbing and an understanding of whether the athlete is caffeine tolerant or caffeine naive, dosages could vary from 50g to 300g before a performance or a training session, especially when you feel wasted.
- BCAAs
Don’t take these. If you want to boost your amino-acid intake, then from a performance sports nutritionist, I can recommend taking complete 9-essential amino acids or a complete protein supplement. These will have long-term training effects. BCAAs and Protein does not have short term performance benefits. Plus, they taste absolutely rank.
- Beta-Alanine
Maybe take this if you are performing to a very high level and need a bit more boost in the power-endurance / endurance areas. Dosing of this needs to happen for about 12 weeks to store in the muscles. The fizzing/tingling effect does not make a difference in performance. In fact, this supplement has no short term performance gain at all. The long-term effects are also quite small, so don’t go taking this for 12 weeks and expect to be an enduro warrior, we’re talking 2-3% performance improvements at most.

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- Multi-vitamins and Minerals
Much performance sports nutrition comes down to micronutrients and deficiencies. You can’t evidently boost any of this past the recommended daily amounts to gain a benefit, but being below the RDA can have huge metabolic and neuromuscular effects. This is particularly important for vegetarians and vegans… or anyone choosing to follow a weird diet that excludes healthy foods. Iron, B vitamins, Omega-3 fatty acids and Vitamin D are often deficient in the UK diet.
Eat more foods that look the same in the supermarket as it did on the tree/in the ground. Eat fewer foods that glow in the dark or take 5 weeks to go off. Whether your vegan or paleo or carbon-neutral, you probably have 80% the same foods nutritionally. You can argue about the nutrition of the remaining 20%, is it Tofu or is it grass-fed local cow, the important thing is all the micronutrients for the other 80% of vegetables and fruits and whole foods.
I hope this all makes sense. Ultimately, don’t be fooled by advertising and podcasts. Eat the right amount of carbohydrate, it won’t make you fat. Maybe take creatine, definitely if you boulder. And play with the usage of caffeine. The other things will all have a very small effect. If you need any more help regarding nutrition support for training, performance sports nutrition, or weight loss coaching, then get in touch at my new company NutriBro.