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Last week I sat down with Michael Easter for a new episode of Two Percent. The first thing he asked about was creatine. He called it “the sacramental wine of fitness people,” and then pointed out that I’d stopped taking it.
That’s true. I’m not taking creatine (right now). That surprises some people. I’ve read pretty much every creatine study published in the last several years, and I recommend it to most people. In May of last year, I wrote a post called Creatine is Overrated. It opened with: “Full disclosure: I take creatine. 5 grams. Every day. And I think you should too.”
A podcast segment only gives you a few minutes, and I’m talking off the cuff. So I thought it would be fun to revisit some of my past posts on creatine to discuss why I started, why I stopped, what I noticed, and what the studies I’ve covered here actually show. To be clear up front, I’m not telling anyone to stop. I didn’t quit because of side effects or because I think creatine doesn’t work (it most certainly does… depending on the outcome).
How I started: a rat study, then a newborn
On the podcast, I said I started taking creatine about five years ago because of a rat study, when my wife was pregnant with our first child.
The rat study came first. I wrote it up in May 2021 (Supplementing with Creatine Reduces the Need for Sleep) and went back to it this January in Physiology Friday #301.
In 2021 I said it “might be worth experimenting with for yourself” and was “worth a shot, especially on those unwanted... sleepless nights.” But I also wrote, “I would limit these findings to the (rat) brain... Nor do we know how these results might translate to humans.”
This rat study planted the idea in 2021, and becoming a parent got me to act on it in early 2024. The motive was the same one I described on the show: sleep and cognition, not getting bigger.
Here’s what that rat study actually showed. The researchers fed male rats chow with 2% creatine monohydrate for four weeks. They measured sleep at baseline, during six hours of enforced wakefulness in the rats’ normal rest phase, and during recovery sleep afterward. After four weeks on creatine:
Time awake during the rest phase went from 43.7% to 61.4%. Total sleep fell from 54.9% to 37.2%, mostly because of less slow-wave (NREM) sleep.
After sleep deprivation, the usual “rebound” was smaller. Delta power, the standard marker of sleep pressure, was 66.3% lower than baseline in the first hour of recovery sleep.
During sleep deprivation, adenosine (the sleepiness signal caffeine blocks) rose 239.4% at baseline but only 151.7% after creatine.
What I find most interesting is that a nutritional intervention seemed to change a core sleep-pressure signal. But the change came mostly from lost slow-wave sleep, and nobody tested whether that’s harmless. In any case, the fact that taking creatine appeared to reduce one’s need for sleep was enough to convince me to take it regularly.
Why I kept taking it
I already knew the strength research, which is a very different body of evidence. Once I was taking creatine, I kept going for the strength benefit when it’s paired with lifting. As a runner, I figured it might help recovery and muscle strength and probably wouldn’t hurt.
My dose went up over time. It was 5 grams a day when I wrote “Creatine is Overrated.” By a reader Q&A last September, I was at about 5 to 10 grams a day, every day. This January I moved my wake-up time earlier, lost 30 to 45 minutes of sleep, and went up to 10 grams a day.
Honestly, though, I never felt the benefits clearly. That isn’t a knock on creatine. Plenty of things that work don’t make themselves obvious day to day.
I stopped this summer while training for a marathon. It was an experiment. I’d taken creatine for about two and a half years without being able to tell what it was doing, so I wanted to see whether I’d notice it gone.
The only clear change was on the scale. I dropped about two to three pounds. That’s expected, because muscle holds more water on creatine. For a runner, losing a couple of pounds isn’t necessarily bad, and I didn’t mind it.
My strength and power felt the same. Running felt a little easier a few pounds lighter. But I’m not measuring any of this objectively. These are impressions, not data.
Some context. I’m 33, around 145 pounds, and running roughly 70 to 80 miles a week. My marathon PR is 2:24 at Boston, which I ran while taking creatine. In June, off creatine, I ran 2:27. But I wasn’t training as hard and wasn’t as fit, so I’m not crediting or blaming those two or three pounds.
Creatine and VO2 max
On the podcast, I said there’s only one study in runners, that it found a lower VO2 max, and that the cause was weight gain lowering VO2 max relative to body weight.
What I wrote about in 2023, in Could Creatine Diminish Gains in VO2 Max?, was a meta-analysis.
Gras et al. (2023) pooled 19 randomized controlled trials with 424 participants. They were 81.7% male, about 30 years old on average, and mostly highly or recreationally trained, with some sedentary people. Doses ranged from 2 to 10 grams a day, for anywhere from 4 days to 6 months, alongside HIIT, resistance, endurance, or combined training. Twelve of the studies used a loading phase of about 20 grams a day for 4 to 7 days.
VO2 max improved less with creatine than with placebo. Breaking that down:
Absolute VO2 max gains were smaller with creatine.
Relative VO2 max (per kilogram of body weight) didn’t differ significantly.
By test type, the effect showed up in cycling tests, but not in running or rowing.
Other measures showed no difference: ventilatory threshold, time to exhaustion, and max power.
The key detail is that body mass changes were identical between groups. So the weight-gain explanation I gave on the show doesn’t hold up (for this meta-analysis). The bigger effect was on absolute VO2 max, which weight gain wouldn’t explain. And the effect wasn’t seen in running tests at all. At the time I wrote, “Maybe it’s just a statistical artifact... possible that what we’re seeing here is noise.”
The water weight I lost when I stopped is still real. It’s just not what this research explains if we look at the entirety of the evidence.
My conclusion then is the same as now: this isn’t a reason for runners to avoid creatine. In 2023 I wrote that “a small decrement in aerobic fitness... in exchange for the increase in strength, power, and muscle mass... seems a worthwhile tradeoff.” I also called it “no free lunch”: small costs, small benefits.
What’s well established
The best-supported finding is also the least exciting. As I put it in “Creatine is Overrated”: “creatine is effective for increasing muscle mass and strength. No debate there.”
Creatine raises phosphocreatine in muscle by about 10 to 40%. Over 8 to 12 weeks of resistance training, people taking it gain about 1.1 to 2.2 kg (2.4 to 4.8 lb) more lean mass and see 8 to 14% bigger gains in bench press and leg press. Not bad, but not superhuman.
There are two caveats. First, some of that mass is water: Lean mass is not all muscle mass. A 12-week study found no lean-mass advantage beyond water, and that produced a round of headlines calling creatine “worthless.” It’s a useful reminder that part of what shows up on the scale isn’t muscle. Second, I’ve written that creatine “does absolutely nothing for muscle mass and muscle strength if you don’t also combine it with resistance exercise training,” because it works by helping you train harder. A new study pushes on that line, so it’s worth looking at closely.
The new “no exercise needed” study
You’ve probably seen this one making the rounds: creatine builds muscle even if you never lift. It’s a 12-week trial from Richard Kreider’s group at Texas A&M, published this year in the Journal of the International Society of Sports Nutrition (write-up here).
They recruited 73 healthy, sedentary adults aged 45 to 65, and 64 finished (average age about 54, 40 women and 24 men). Each participant chose whether to join a structured program, which combined resistance and aerobic training three times a week with a calorie-reduced diet, or to skip it. Within each group, people were randomized, double-blind, to 10 grams of creatine monohydrate a day (two 5-gram doses) or a placebo.
Here’s what got everyone’s attention. In the group that didn’t exercise, creatine users gained about 1.1 kg (2.4 lb) of lean tissue while the placebo group stayed flat. They also got stronger on the bench press and leg press and improved muscular endurance. In the exercise group, adding creatine produced bigger gains in strength and time to exhaustion, plus a larger drop in body fat percentage. The authors also report better blood lipids, HbA1c, and some memory measures, but they call the cognitive and biomarker findings exploratory.
So is my “does absolutely nothing” line wrong? Partly, and I’d rather say so. For untrained, middle-aged people, creatine on its own seems to do something. But I’d read it carefully:
The lean mass gain is probably partly water. DXA can’t tell water from muscle, and creatine pulls water into muscle cells. That’s the same caveat as the 12-week “worthless” study, just in the other direction.
The strength gains are harder to explain with water alone. That’s the most interesting finding. It’s also worth remembering these were sedentary people starting from a low baseline, so the result may not carry over to someone who already trains.
The no-exercise groups were small, about 13 people per arm by one analysis, and the result was a single 12-week trial.
People chose whether to exercise, so the comparison between exercisers and non-exercisers isn’t randomized. Only the creatine-versus-placebo comparison within each group is.
The dose was 10 grams a day, double the usual scoop.
Exercise plus creatine still won. Nothing here says creatine replaces training.
My takeaway is that if you’re middle-aged and not training yet, creatine might give you a small head start on lean mass and strength. It’s a reason to take it alongside starting to lift, not instead of lifting. And it’s one more data point that fits my “over 60, it might offer a small edge” view of who benefits most.
What’s oversold
This is what bothers me most. Online, creatine gets talked about like a cognitive enhancer, almost like caffeine. I’ve heard people say they took 20 or 30 grams in the morning and their brain “lit up.”
I’ve been honest about that feeling myself: “If I take a 20g dose... my brain might very well feel supercharged... Is it creatine? Maybe. Are my expectations playing a role? Certainly.”
Creatine is not an acute stimulant. It works by building up in your tissues. Muscle saturation takes 3-5 grams per day for about 1 month, and creatine doesn’t necessarily accumulate meaningfully in the brain overnight. The brain seems to take longer and possibly higher doses.
Michael added useful context: the standard scoop is 5 grams, and a lot of people are now taking four to six times that.
The everyday evidence for the brain is modest. In one study, 5 grams a day for six weeks improved working memory and intelligence scores in vegetarians only. Omnivores saw small or no effects. A 2018 systematic review found small benefits for memory, processing speed, and executive function, mostly in people who were stressed, sleep-deprived, or older. Psychiatrist Dr. Nicholas Fabiano, whom I had on the podcast last year (Creatine for the Brain), argues in his review that 10 grams or more a day may be the right dose for the brain.
My summary hasn’t changed: If you’re healthy, young, well-fed, and not sleep-deprived, creatine probably won’t do much for your mental performance. But if you’re an overtrained athlete, a chronically stressed student, or over 60? It might offer a small edge.
Michael also pushed back on the mental-health claims, which he thinks rest on weak studies. The best thing I’ve covered is a small pilot that added creatine to SSRIs in clinically depressed people, and more research is needed there.
Where the brain claims hold up
The strongest case for creatine and the brain comes from acute sleep deprivation, and the details matter.
I first wrote up the key study in Physiology Friday #208 and came back to it in Physiology Friday #334.
It’s Gordji-Nejad et al. (2024), a randomized crossover trial against placebo in 15 young adults (average age 23; 8 women and 7 men). Each took a single dose of 0.35 grams per kilogram of body weight, about 20 to 32 grams for someone weighing 70 to 90 kg, around 8:30 p.m. at the start of a planned night awake. Compared with placebo:
Brain creatine rose about 5%.
Fatigue was 8% lower at 2 and 4 a.m.
Working memory improved 18%, language 29%, logic 16%, and numeric performance 24%.
The usual drop in brain energy markers (PCr/Pi and pH) was prevented.
The effect peaked at about four hours and lasted up to nine.
A 2026 follow-up from the same group gave 29 people a smaller dose, 0.2 g/kg. Creatine again reduced the decline on several cognitive tasks, though the effects were smaller.
On the podcast, I called these “20 to 40 grams.” The point is that they’re large, single doses, taken heading into a night of sleep loss. The researchers think very high blood levels, combined with the energy demand of staying awake, may temporarily increase uptake into the brain.
That’s why I push back when people take creatine the morning after a bad night. That’s a different intervention. Maybe it helps, but these experiments don’t show it. As I wrote in 2024, “Creatine isn’t a cure for sleep deprivation, but it might be a band-aid.” If you know a night of sleep loss is coming, the protocol I described was 0.35 g/kg a few hours before your normal bedtime. For chronic sleep loss, I described 0.17 g/kg a day for a few weeks.
Older adults
On the show, I said creatine might help people 60 or older who are dealing with dementia. I haven’t actually written up a dementia study, so I’ll stick to what I’ve covered. Studies find small cognitive benefits concentrated in groups that included older people, which is where my “over 60” line comes from.
There’s also a bone angle. In a one-year trial in postmenopausal women (study), creatine plus resistance training raised femoral neck bone density about 1.2%, while the group that didn’t take creatine saw no change. But as I wrote, “creatine won’t save your bones on its own.” The lifting is what matters.
So where does that leave me?
I took creatine for about two and a half years, mostly for sleep insurance and strength, and couldn’t feel it. I stopped as an experiment and so far notice almost nothing: about the same strength, about the same running, a couple of pounds lighter.
My position hasn’t changed much, though. Last year I wrote, “I think you should too.” I still think most people will benefit from supplementing.
But now I’d put it this way: if you lift regularly, creatine is a reasonable, well-supported thing to take. If you’re a runner, the VO2 max concern is small and may be noise. If you’re hoping a scoop will make you sharper, the evidence mostly isn’t there unless you’re short on sleep or older. As I said in that post, “It’s not a miracle supplement, and that’s okay.”
What I’m actually doing now
I’m not taking creatine right now.
I’m still persuaded by the strength evidence. If you’re lifting regularly, I think it’s a reasonable thing to take. If you’re middle-aged and not lifting yet, the new Texas A&M trial suggests it may help a little on its own, but start lifting too. Take 3 to 5 grams a day, every day. You’ll be saturated in about a month, and there’s no need to cycle. Timing doesn’t matter much, though taking it within about 30 minutes after a workout may help uptake.
If you’re a runner worried about a little weight gain or your VO2 max, I wouldn’t let that stop you. The data are small and noisy, and the strength tradeoff looks worth it.
If you’re trying creatine for a night without sleep, know what was studied: a large dose taken before the night, not a scoop the morning after.
I’m not going to pretend a morning scoop fixes your brain. If you’re healthy and sleeping, that part of the pitch doesn’t hold up.
Now I want to hear from you. Do you take creatine? How much? What’s your experience?
Thanks for reading.
~Brady~
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I stopped last fall. I couldn't suss out benefits, including cognitive, and I didn't like how the (admittedly small) weight gain made me feel.
More important, you missed a golden opportunity. You wrote, "So the weight-gain explanation I gave on the show doesn’t hold up (for this meta-analysis)." I was really hoping the sentence would end "doesn't hold water."
Took creatine for a year as a runner. Gained some water weight. Didn’t really notice I recovered better from workouts. Might have gotten a little stronger in the gym.
Went off creatine recently. Noticed my HRV shot up (about 20%). Also noticed my HRV rebounded quicker post hard sessions vs on creatine. Water weight came off.
I don’t see enough benefits for an endurance athlete to be on creatine. That’s just my experience. Also I can’t find any studies that state creatine is beneficial for endurance (runners, cyclist) athletes.