A popular gym supplement might be doing squat to build muscle, according to an eye-popping new study.
Creatine is a naturally occurring chemical found in muscle cells and foods such as red meat, fish and poultry. Many athletes take creatine supplements because they are purported to increase muscle mass, enhance power output and boost performance.
But new research out of Australia reports that adding creatine to a weightlifting regimen does not build muscle faster, sparking new questions about the efficacy of the supplement.
“We’ve shown that taking 5 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 senior study author Mandy Hagstrom, from the University of New South Wales School of Health Sciences.
“The benefits of creatine may have been overestimated in the past, due to methodological problems with previous studies,” she added.
Hagstrom said participants in previous studies started creatine supplementation and exercise programs concurrently, making it difficult to discern which led to muscle gains.
Researchers also overlooked the potential for creatine to cause water retention, she noted.
The UNSW trial put 54 healthy people between 18 and 50 through a 12-week resistance training program.
Those in the supplement group took 5 grams of creatine daily — the recommended maintenance dose is 3 to 5 grams.
Participants began creatine a week before starting the exercise program, which included three supervised resistance training sessions a week.
They didn’t do a creatine-loading phase, which involves taking 20 to 25 grams daily for up to a week to rapidly saturate muscle creatine stores.
The researchers said creatine loading isn’t necessary to reach saturation levels and can cause bloating or an upset stomach.
“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.
Participants, who were directed to keep a food log to show their diet remained steady, had their bone mineral density and body composition measured with DEXA scans.
Supplement takers — especially women — gained more lean body mass in the first week. The average was about 1.1 pounds more than the control group.
But pretty quickly, those taking supplements dropped back to match the control group gains.
Both sets of participants put on an average of about 4.4 pounds of lean body mass during the program.
“The people taking the 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,” Hagstrom said.
“Once they started exercising,” she continued, “they saw no additional benefit from creatine, which suggests that 5 grams per day is not enough if you’re taking it for the purposes of building muscle.”
Hagstrom said previous trials, which lasted four to 12 weeks and didn’t have a wash-in period, found those on creatine gained about 2.2 pounds more muscle.
“In theory then you would have expected our creatine group to put on [6.6 pounds] of muscle over the 12-week program, but they didn’t,” said first study author Imtiaz Desai, from UNSW’s School of Health Sciences and Neuroscience Research Australia.
The findings were published last week in the journal Nutrients.
“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,” he 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.”
Desai’s team suggests further studies explore dosing with 10 grams instead of 5 grams.
Trials should also be longer, with measurements of body water content and creatine absorption and tracking of menstrual cycles, which can affect fluid retention.
“It would be really interesting to see if creatine has more of a long-term benefit,” he said. “When you start weight training, you have 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.”
