Maximising muscle gains with creatine: how well does it work?

Creatine is one of the most well-researched and effective sports nutrition supplements for improving exercise performance. So it is no surprise that interest in using creatine supplements to enhance performance during intense activity has grown dramatically over the last few years. One of the most common ‘use cases’ for creatine supplements is for muscle and strength gains. This makes creatine a popular choice by strength and power sports athletes, bodybuilders and recreational exercisers to supplement their resistance training. In this podcast episode, I dig deeper into what creatine is, how it may work and importantly: what the latest scientific evidence has to say about how it performs in maximising muscle gains.

Links referred to in the podcast

• IOC Consensus Statement on dietary supplements for use by high-performance athletes https://bjsm.bmj.com/content/52/7/439
• Systematic review of creatine supplementation and body composition https://pubmed.ncbi.nlm.nih.gov/39074168

Episode transcript
To access the full episode transcript, go to the following link and select the individual podcast episode and then click on the ‘Transcript’ tab https://thinkingnutrition.buzzsprout.com

Connect with me
Instagram doctimcrowe
Facebook Thinking Nutrition
X CroweTim

Transcript

Creatine is one of the most well-researched and effective sports nutrition supplements for improving exercise performance. So it is no surprise that interest in using creatine supplements to enhance performance during intense activity has grown dramatically over the last few years. One of the most common ‘use cases’ for creatine supplements is for muscle and strength gains. This makes creatine a popular choice by strength and power sports athletes, bodybuilders and recreational exercisers to supplement their resistance training. In this podcast episode, I’ll dig deeper into what creatine is, how it may work and importantly: what the latest scientific evidence has to say about its potential performance benefits.

Creatine is a naturally occurring compound found in our muscles in the form of creatine phosphate. The phosphate part of creatine is a valuable aid in the rapid resynthesis of high-energy ATP from ADP during short-term maximal exercise such as sprinting or power weight training.

So, think of creatine as like a short-term anaerobic power source that the body can call upon when its energy demands are at a peak. Theoretically, the more creatine phosphate that you have in your muscles, the higher the intensity at which you can train. High-intensity training stimulates the muscles to grow and adapt, which, in turn, improves performance. Win, win.

Because creatine is mostly found in our muscles, that means animal foods such as meat and fish make for excellent dietary sources. But our bodies can naturally produce it as well. And of course, supplementing with creatine can boost muscle stores too. Though vegetarians do tend to have lower natural levels of creatine so there could be a case that supplementation could benefit them more.

So, what does the scientific evidence have to say about creatine and sports performance in general? There have been well over 200 studies, reviews and meta-analyses done so this is one supplement that has been well-researched and is backed by real science, not bro science. In fact, creatine was one of the few supplements to get the tick for having good evidence behind it in the 2018 IOC Consensus Statement on dietary supplements for use by high-performance athletes. And I’ll link to this document in the show notes https://bjsm.bmj.com/content/52/7/439

That large research base finds that the greatest benefits of creatine are in recovery from high-intensity bouts of exercise with short rest intervals. So, what that means is that it may not make a person run a faster 100m, but they’ll be able to run faster sprint times if they’re doing it repeatedly such as in intermittent activity sports like football where they may be high-intensity bursts of activity for less than 30 seconds followed by periods of relative rest.

There is also some evidence for a benefit of creatine supplementation to enhance endurance performance which results from increased or improved protein synthesis, glycogen storage and thermoregulation.

But probably the main benefit of taking creatine is in resistance weight training with positive adaptations including lean mass gains and improvements in muscular strength and power. Benefits have been reported in men and women, although most studies have been conducted on men. More about that shortly.

It is that effect of creatine on changes in body composition related to improvements in strength and performance with resistance exercise that I want to dig deeper into for this episode. And for that, we have a recently published systematic review of 12 randomised controlled trials involving 362 adults with 87% of them male which sadly is the usual weighted bias we see in a lot of sports nutrition research. The population focus of the review was on healthy adults younger than 50 years who were considered non-athletes so more your active exercisers group.

The studies used regimens of either a fixed dose of supplemental creatine or individualised based on body weight with most of the studies using an initial loading phase followed by a lower maintenance dose. I’ll talk more about dosing regimens later in the episode.

The types of resistance training included full-body workouts targeting both upper and lower-body muscle groups done 3 to 5 times per week. Training volume was in the range of 3 to 5 sets per exercise per session with repetitions ranging from 3 to 20 per set. And the duration of the interventions ranged from 4 to 11 weeks. I’ll link to the study in the show notes. https://pubmed.ncbi.nlm.nih.gov/39074168

So what did they find? Well, the primary outcome of interest was changes in fat-free mass with secondary outcomes of changes in body fat percentage and body-fat mass. And the news was positive as creatine supplementation combined with resistance training could increase fat-free mass by an additional 1.1 kilograms compared to resistance training alone and with good agreement between the studies on this finding.

On top of that, creatine supplementation reduced body fat percentage by almost a percentage point and body fat mass by 0.7 kilograms more than resistance training alone.

Of interest, the effects of creatine on body composition were similar between trained and untrained individuals and training volume also did not influence the outcomes.

No study is perfect and it is important to be aware of its limitations. Some of the studies assessed body composition by DEXA which stands for dual-energy X-ray absorptiometry. A limitation of DEXA is that the results can be influenced by changes in body water which creatine is certainly known to do as water retention is a well-known side effect. And as I mentioned before, the results may not be fully applicable to women as most of the participants were men. Hormonal effects are a major confounding difference between men and women.

How creatine helps with resistance training isn’t fully understood. Though is likely a combination of reasons such as changing gene expression of the muscle protein myosin, influencing insulin-like growth factor production, stimulating muscle growth regulatory factors, improving cellular hydration, and altering inflammation and oxidative stress responses. But let’s not forget one of the more simple explanations is that creatine supplementation can increase creatine phosphate stores and help with the resynthesis of ATP, thus enabling a larger volume or more intense training and through that a greater muscle hypertrophy response.

For someone who is considering trialling creatine, what should you be aware of? There are many different forms of creatine available on the market, but creatine monohydrate is the cheapest and most effective form. Another option is micronised creatine monohydrate, which dissolves in water more easily and can be more practical.

A typical creatine loading protocol is 20 grams per day or about 0.3 grams per kilogram of bodyweight divided into 4 doses across the day and doing that for 5 to 7 days in a row. After loading, a maintenance dose of a single 3-5 grams per day can be used. Creatine loading has been shown to increase muscle creatine content by around 20% and this is what explains the sports performance benefit. With a loading protocol, maximum muscle creatine levels can be obtained in around a week. Alternatively, this can be achieved by just doing the daily dosing of around 3 to 5 grams which will get you there in about a month.

Creatine is usually taken together with some carbohydrate to increase insulin release, as that insulin will increase creatine uptake into muscle. 

Creatine is not something you need to use all year round, but instead when you have particular performance goals. When you stop taking creatine, body levels will start to drop and return to baseline levels after around four weeks.

What about the downsides of taking creatine? One known downside is weight gain of around 1 to 2 kilograms. All that extra creatine that is being stored in the muscles pulls in additional water into the cell. So, for athletes in weight-sensitive sports such as endurance athletes or in events where body mass must be moved against gravity such as high jump or pole vault, or where athletes must achieve a specific body mass target such as lightweight rowing, then the performance gain of taking creatine must be balanced against the weight gain.

On the question of safety, creatine is considered safe for healthy adults. Concerns in the past have been raised about:

• Muscle cramps due to higher muscle water content
• Headaches due to greater water storage in the brain
• Muscle tears and injuries due to increased training
• Insulin resistance leading to diabetes
• Possible higher risk of cancer
• And kidney disease

However, as the research field has grown, there is little evidence to support a greater risk of any of these concerns. Things like cramping, GI problems and muscle injuries occur in both creatine and non-creatine users with little difference in the rate of occurrence. Concerns about insulin resistance and cancer have been largely dismissed.

The only issue of note is that for athletes with pre-existing kidney problems, the extra protein load from creatine could place additional stress on the kidneys, but this is not to do with creatine per se, but just the presence of additional protein in the diet from supplementation. 

A word of warning though that If creatine is taken without enough water, stomach cramping can occur. Also, diarrhoea and nausea can occur when too much creatine is taken at once, in which case doses should be spread throughout the day and taken with meals.

So, let’s wrap all this up. Creatine is one of the few nutritional supplements for which research has consistently shown a sports performance benefit. The use of all supplements and sports foods by athletes though involves a balance between the potential benefits set against potential risks such as health side-effects, anti-doping rule violations from contamination, and redirection of resources from real performance-enhancing factors. So, take this into account when considering taking any sports supplement. And seek out personalised advice from a sports dietitian. You can connect with an Accredited Sports Dietitian as well as access a great range of resources through the website of Sports Dietitians Australian at www.sportsdietitians.com.au

So that’s it for today’s show. You can find the show notes either in the app you’re listening to this podcast on, or else head over to my webpage www.thinkingnutrition.com.au and click on the podcast section to find this episode to read the show notes.

If you find this podcast of value, then please consider sharing it with your friends and colleagues. This all helps to increase the reach of the podcast, which means a big win for credible evidence-based nutrition messages and making the world a slightly less confusing place.

I’m Tim Crowe and you’ve been listening to Thinking Nutrition.