A new study has found that taking five grams of a creatine supplement daily, which is the upper limit of the recommended daily dose, while lifting weights doesn’t lead to more muscle gains. It's possible the popular supplement's effects have been overstated.
Gym workouts and creatine go hand-in-hand. As a supplement, creatinine is often used to increase athletic performance. Creatine supplements are so commonplace that Global Market Insights valued the 2024 market at a whopping US$514.4 million, a figure that’s expected to continue growing.
A new study led by the University of New South Wales (UNSW) Sydney examined whether taking the upper recommended daily "maintenance" dose of creatine supplement while lifting weights promoted more muscle growth than not taking the supplement.
“We’ve shown that taking five grams of creatine supplement per day does not make any difference to the amount of lean muscle mass people put on while resistance training,” said Dr Mandy Hagstrom, an exercise scientist from UNSW’s School of Health Sciences and the study’s senior author. “The benefits of creatine may have been overestimated in the past, due to methodological problems with previous studies.”
Previous research into creatine’s effects has found that it can help build muscle, enhance athletic performance, and even reduce depression. But, in many studies, creatine supplements and exercise programs have been started on the same day, making it difficult to attribute the effect of each on muscle gains. The studies have also not factored in creatine’s propensity to cause water retention. The researchers behind the present study wanted to address these issues.
So, they recruited 54 individuals with an average age of 31 and randomized them into two groups: one took 5 grams a day of creatine monohydrate (CrM) for 13 weeks while they undertook 12 weeks of resistance training, and the other exercised without taking creatine. The creatine group had a one-week "wash-in" period where they took 5 g/day of CrM before they started training.
“We had what we call a wash-in phase, where half of the participants started taking the supplement, without changing anything else in their daily life, to give their body a chance to stabilize in terms of its response to the supplement,” Hagstrom said.
All participants were relatively healthy and doing less than the recommended 150 minutes of minimum moderate-intensity exercise per week. They all undertook the same resistance training program, and their bone mineral density (BMD) and body composition measurements were taken at different stages throughout the study period. They also kept a food log, which showed no significant differences in their diets.
In that first week, in the absence of training, those in the creatine group, particularly the females, put on an average of 0.5 kg (1.1 lb) more than the control group. But the weight soon dropped back down to match the control group.
“The people taking creatine supplement saw changes before they even started exercising, which leads us to believe that it wasn’t actual real muscle growth, but potentially fluid retention,” said Hagstrom. “Then once they started exercising, they saw no additional benefit from creatine, which suggests that five grams per day is not enough if you’re taking it for the purpose of building muscle.”
The findings differed from those of previous research where no wash-in period was used and participants on creatine gained one kilogram (2.2 lb) more muscle than those not taking the supplement after exercising for periods between four and 12 weeks.
“In theory, then, you would have expected our creatine group to put on three kilograms [6.6 lb] of muscle over the 12-week program, but they didn’t,” said lead author of the present study, Dr Imtiaz Desai, from UNSW’s School of Health Sciences and Neuroscience Research Australia (NeuRA).
Participants in the creatine group didn’t undergo a "loading phase" – taking between 20 g and 25 g of creatine daily for five to seven days, a practice common among gym-goers. The researchers avoided this practice because it has been known to cause gastrointestinal issues like nausea and diarrhea.
The current recommended daily intake of CrM as a dietary supplement is three to five grams. However, the study’s findings suggest that further – probably longer –research is needed to determine whether taking more than five grams of creatine a day has a more significant effect on muscle growth.
“It would be really interesting to see if creatine has more of a long-term benefit,” said Desai. “When you start weight training, you have to those beginner gains in strength and those start tapering off around the 12-week mark and become slower, so it’s possible the support from creatine might come at a later stage.”
The researchers hope their study prompts consumers to question the claimed benefits of creatine supplements.
“For your average person taking creatine to boost their gains in the gym, this will hopefully change their perception about what it can help them achieve,” Desai said. “For professional athletes, particularly those who must be at a particular weight for their sport, the findings may inform how and when they take the supplement.”
The study was published in the journal Nutrients.
Source: UNSW Sydney
