As a dietitian working with endurance athletes, I’m constantly asked about creatine for endurance athletes and whether it’s worth incorporating into training for runners, cyclists, and ultra-endurance athletes.

To get answers, I reached out to the expert Dr. Scott Forbes. Dr. Forbes is an associate professor at Brandon University, a scientific advisor for the International Society of Sports Nutrition, and a leading authority on creatine research, with over 130 peer-reviewed studies and five book chapters.

Whether you’re new to endurance sports or a seasoned athlete looking for an edge, I hope this podcast episode will help you decide whether creatine is right for your training.

Looking for a quality and reputable creatine? I’ve partnered with Thorne, my favorite supplement brand. You can use this affiliate link to get 15% off your order!

What Is Creatine and How Does It Work?

Dr. Forbes started by explaining that creatine is a compound made up of three amino acids: arginine, glycine, and methionine. It’s naturally present in our bodies and is primarily stored in our muscles, but it can also be found in foods like red meat, seafood, and dairy.

Most of us only reach about 80% of our muscles’ potential creatine saturation through diet alone, which is why many people turn to creatine supplementation. For athletes—especially those who are vegetarian or vegan and may have lower baseline levels—creatine supplementation can help increase muscle creatine stores beyond what’s achievable through food alone.

The Myth: Creatine Is Only for Strength Athletes

One common misconception is that creatine is only beneficial for bodybuilders and strength athletes. While it’s true that creatine is best known for its role in boosting short, high-intensity efforts, there’s a growing body of evidence showing that creatine can also offer benefits for endurance athletes.

According to Dr. Forbes, endurance athletes can especially benefit from creatine in situations that call for short bursts of power, such as:

• Hill climbs during an ultra-marathon
• Sprinting to the finish in a race
• Breakaway moments in cycling

Creatine for High-Intensity Efforts Within Endurance Training

Dr. Forbes shared two studies highlighting how creatine can be beneficial during high-intensity segments within endurance activities:

• Study #1: In a 120-km cycling time trial, elite cyclists performed faster on the final high-intensity sprint segments when supplemented with creatine.
• Study #2: In a 30-minute cycling workout, participants taking creatine achieved an 18% higher power output in 15-second sprints, even completing an additional 30 minutes of threshold training afterward without the fatigue seen in the placebo group.

These results show that creatine can provide an extra edge for those peak moments within endurance events—times when that final push could mean the difference between winning and finishing.

Understanding and Managing the Potential for Weight Gain

One of the most common concerns I hear from runners and cyclists is the potential for weight gain. Many endurance athletes fear that added water retention from creatine might weigh them down or even slow them in competition.

Dr. Forbes addressed this by pointing out that, on average, people who supplement with creatine experience less than 1 kilogram (about 0.86 kg) of additional weight, much of which comes from water retention in the muscles. Over time, some of this weight gain may be lean muscle, which can actually enhance performance, strength, and durability.

The key takeaway? If you’re concerned about weight gain, consider integrating creatine during the off-season or high-volume training blocks rather than right before a race.

Creatine for Endurance Athletes: Tips for Optimizing

When it comes to creatine supplementation, timing and dose matter:

• Start with 3 to 5 grams daily instead of a loading dose. This daily amount will build up muscle creatine levels gradually, achieving full saturation in about 28 days.
• If you prefer quicker results, a loading phase of 20 grams per day (spread across four doses) over five to seven days will saturate muscles faster.
• Take creatine with carbs for optimal results! Co-ingesting creatine with carbohydrates can improve glycogen replenishment after training and may boost muscle recovery for those doing high-volume or back-to-back training sessions.

Creatine for Female Athletes: Debunking the “Bulk” Myth

Many women are concerned that creatine might make them bulkier, but Dr. Forbes assured us that muscle gain with creatine is subtle. In fact, a meta-analysis found that muscles gain only about 1 millimeter of thickness with creatine supplementation. It’s a small difference that adds strength without substantial bulk, making it a beneficial addition to training for women who want to maintain a leaner build.

For women tracking their cycle, Dr. Forbes highlighted studies showing that creatine might even have varying effects across the menstrual cycle. Research suggests a bit more water retention in the luteal phase, but there’s no evidence of major weight fluctuations.

Creatine and Age: Benefits for Older Athletes

Creatine can be especially beneficial for athletes over 50, particularly women. Dr. Forbes shared recent research showing that creatine helped older women maintain muscle strength even though there wasn’t a significant increase in muscle mass. Stronger muscles are essential for longevity, balance, and preventing injuries. For those focused on endurance sports later in life, creatine supplementation can help with strength maintenance, preserving bone health, and reducing age-related muscle loss.

Maintaining Gains: What Happens if You Stop Taking Creatine?

For athletes wondering if they’ll lose muscle mass or strength if they stop creatine, Dr. Forbes noted that muscle creatine levels will gradually return to baseline over 4 to 6 weeks. Importantly, stopping creatine doesn’t cause any quicker muscle loss or strength decline than usual, so as long as you continue strength training, you’re likely to maintain those gains.

Future Research Directions for Creatine

Dr. Forbes concluded by sharing some of the exciting research underway. He and his team are currently exploring how creatine might help ultra-endurance athletes in 50-km races, studying its impact on muscle inflammation, oxidative stress, and recovery. Another fascinating area is brain health, where studies are examining creatine’s potential to aid in concussion recovery, protect against neurological damage, and possibly even improve memory in aging populations.

With research expanding, creatine might soon be appreciated as a supplement that supports both physical and cognitive performance.

Looking for a quality and reputable creatine? I’ve partnered with Thorne, my favorite supplement brand. You can use this affiliate link to get 15% off your order!