Sports Supplementation – Is It Worth the Hype?

Supplementating is a popular means of attempting to improve sports performance and/or training. We have previously covered how probiotics can aid in improving sports performance here, but this piece will focus on two different but very populars sports supplementation substances: creatine and caffeine.

Caffeine tends to be used for an energy boost, whereas creatine is used more for muscle endurance increasing muscle mass. 


Creatine is a naturally-occurring substance found in our muscles and can be sourced from the diet. It is nearly exclusively sourced from animal proteins (think meat and fish) and in very small amounts in animal products (egg and dairy).

Creatine tends to be used as a supplement by bodybuilders for gym-goers as a means of increasing their muscle mass. The theory behind this is that by supplementing with creatine, the levels of creatine in our muscles will increase, allowing us to have more Phosphocreatine (also known as PCr) available for use at the beginning of a bout of high-intensity exercise. This essentially means you can lift more for longer.

The biochemical process of converting phosphocreatine to creatine
The  biochemical process of converting phosphocreatine to creatine

This diagram shows the biochemical process of converting phosphocreatine to creatine. PCr uses Adenosine Diphosphate (ADP) to create Adenosine Triphosphate (ATP) and creatine; ATP is every and is what our muscles use for contraction. Therefore, the more PCr that is pre-loaded in the muscles, the more readily available energy you’ll have, so you can lift more for longer.

Is it worth it?

Research looking at creatine supplementation is contradictory for the most part – it seems to exhibit both positive, and more negative effects, depending on the tested population.

It has been suggested to have a positive effect on muscle strength, performance, and hypertrophy in trained healthy, young populations, essentially meaning that young people who are already training may benefit from creatine supplementation (Wu, et al., 2022).

This is because having phosphocreatine in our muscles helps ‘preload’ the muscles to synthesise more ATP, which is used for muscle contraction (along with many other functions). As such, it may help build strength if used over time.

It has also been shown to have a positive effect on the elderly population increasing muscle mass especially if resistance training (Candow, et al., 2019). However, there does not seem to be an obvious benefit on muscle strength in the same population – even after 12 months of training (Wu, et al., 2022). This ultimately means it may help elderly people to look more muscular, but won’t necessarily improve muscle strength – so results seem to differ depending on the age group in question.

Currently, it seems that there may be some benefits of supplementing with creatine, but this isn’t guaranteed – while it’s a heavily researched sports supplement, the studies that have been done tend to be in quite niche populations, making it difficult to draw firm conclusions. Regardless, the side effects are minimal, so it won’t necessarily cause any harm.


Caffeine is commonly used as a morning pick-me-up for most but is also used as a performance-enhancing supplement. As it is a stimulant, it can increase energy levels and focus when consumed in the right proportions – if going overboard, it can lead to anxiety and jitters.

Caffeine is a heavily-researched substance with a lot of possible benefits on sports performance. 

It famously causes a spike in alertness and can alter one’s mood as well – some may feel more relaxed or have an improved mood (think the stereotypical “don’t talk to me until I’ve had my morning coffee”!), whereas some may experience more negative side effects.

How it works

Caffeine is absorbed through our gastrointestinal tracts and then moves through the cellular membranes, to be broken down by the liver. This is a speedy process, and the products that the liver breaks caffeine down into (paraxanthine, theophylline and theobromine) can be seen (if tested) in the bloodstream within 45 minutes (but as quickly as 15!), with levels peaking around one hour after consumption.

In Sports Performance

Caffeine works by affecting our central nervous system and reducing the perception of fatigue (3). However, there are also associations with adrenaline stimulation, fat mobilisation, and muscle contractility. These have mostly been shown in more endurance-style exercise but also has promising results with intermittent/interval training, as well as powerlifting (2). 

Typically the pitfall that most succumb to is consuming caffeine in place of a pre-workout snack/meal. This can cause the less desirable side effects of caffeine, like the aforementioned anxiety and jitters. To negate this, it is recommended to consume caffeine with food.

Perhaps surprisingly, caffeine may also make up a good post-workout refuel. Studies have shown that, when consumed in conjunction with carbohydrates caffeine can improve the rate that the body replenishes glycogen stores, which in turn can reduce recovery time (2). This is especially beneficial if you are someone that trains intensely and frequently, or if your sessions tend to be quite close together.

Whether or not you should utilise caffeine as a performance enhancer is entirely up to you, and should be based on the impact that it has on you. If you experience the more negative impacts of caffeine, you’d likely be better off forgoing the shakes for improved glycogen replenishment. However, if you’re someone that can fall asleep after having a coffee and are looking to slightly improve your performance, caffeine may be an easy way of doing so. If you already consume caffeine, try altering the timing of when you consume it to be more around your training sessions!

Ultimately, everyone’s bodies react differently to different supplements or substances – there’s no set rule on whether you should use sports supplements or not, as it depends on how effective you perceive the supplement in question to be. If you believe the supplement to aid your performance, whether that’s genuine or perhaps a placebo effect, then continue to use them as have. If you don’t tend to notice a difference, or maybe you feel the less positive impacts, then it’s best to leave them out. Listen to your body and works out what works best for you!


(1) Candow DG, Forbes SC, Chilibeck PD, Cornish SM, Antonio J, Kreider RB. Effectiveness of Creatine Supplementation on Aging Muscle and Bone: Focus on Falls Prevention and Inflammation. J Clin Med. 2019 Apr 11;8(4):488. doi: 10.3390/jcm8040488. PMID: 30978926; PMCID: PMC6518405.

(2) Goldstein, E., Ziegenfuss, T., Kalman, D., Kreider, R., Campbell, B., Wilborn, C., Taylor, L., Pedersen DJ, et al. High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. J Appl Physiol (1985). (2008)

(3) Kench A, Selvadurai H, in Diet and Exercise in Cystic Fibrosis. The Sports Medicine Resource Manual, 2015, Pages 317-332

(4) Willoughby, D., Stout, J., Graves, B., Wildman, R., Ivy, J., Spano, M., Smith, A. and Antonio, J., 2020. International Society Of Sports Nutrition Position Stand: Caffeine And Performance.

(5) Wu SH, Chen KL, Hsu C, Chen HC, Chen JY, Yu SY, Shiu YJ. Creatine Supplementation for Muscle Growth: A Scoping Review of Randomized Clinical Trials from 2012 to 2021. Nutrients. 2022 Mar 16;14(6):1255. doi: 10.3390/nu14061255. PMID: 35334912; PMCID: PMC8949037.

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Meghan Foulsham

Published by Meghan Foulsham

Meghan's fascination with metabolism and the effect of diet on the body covered in her BSc Biochemistry, paired with being a passionate mental health advocate, led her to a Master's degree in Eating Disorders and Clinical Nutrition. Using this, Meghan works with clients to help them reach their goals in the most sustainable way, without sacrificing or risking their mental health.

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