Most cyclists think creatine adds bulk, kills the climbs, and belongs in the gym. After 10 years of believing exactly that, Anthony Walsh ran the experiment himself.
5 grams a day. 30 days. The sprint numbers were hard to argue with.
Listen to the full conversation on the Roadman Cycling Podcast →
Why Anthony Finally Tried It
Anthony has held a Cat 1 license unbroken since 2010. He came up through the French system. His default on supplements is sceptical, and creatine sat in the same bucket as beetroot juice, ketones, and carb rinses for over a decade. A fad. Something for guys in the weight room. Not for skinny climbers chasing grams per watt.
What changed was a podcast conversation. David Dunne, who handles nutrition for several WorldTour programmes, put creatine on his short list of supplements every cyclist should take. A few of Anthony's older athletes started asking about it. The reading he had done was a decade out of date.
So he ran the experiment.
The Protocol
The protocol was deliberately boring.
5 grams of creatine monohydrate per day. One scoop. Added to a post-session recovery shake. No loading phase. No cycling on and off. The cheapest supplement on the shelf — about $15 a tub, lasts months.
The point of skipping the loading phase was practical. 20 grams a day for a week saturates muscle faster, but it tends to give riders GI issues, and the end point is the same either way. On a steady 5g daily dose, full saturation arrives at 3 to 4 weeks. That matches the timeline of what happened in the data.
If you are going to run this yourself, log it in TrainingPeaks or whatever you already use. Date the start, log the weight, log the power numbers. The whole point of an n=1 experiment is being honest about what changed.
Week One: Nothing
In the first seven days Anthony noticed precisely nothing on the bike. No bulging quads. No surge in power. No subjective change at all. People who try creatine and quit at day five quit at the wrong point — the muscles are not yet saturated, and the supplement has not started working.
What he did notice was the bathroom scales. Anthony left them in the hall, and every morning he had to step over them on the way to the bathroom. The number started moving.
Week Two: The Weight
By the end of week two he was up 1.5kg.
His own words on the podcast:
By week two, I was up 1.5 kg. So that's three lbs if you're watching over in the US. And I was a little freaked out a little bit because if you think 1.5 kg, one of these bottles is 750 mil. So, it's like carrying two full extra bottles of water everywhere you go. And it is true what the studies say. It's mostly water weight.
The research lines up. Most cyclists put on 1 to 2kg in the first two weeks. It is held inside the muscle cells, not as fat. The mirror test confirmed it — no extra body fat, just the slightly fuller look that comes with muscle holding more water.
For a climber, that 1.5kg is a real number. It is roughly the difference between Anthony's offseason weight and his on-season race weight. There is no point pretending it does not matter on a steep climb. It does. The honest read is that creatine swaps a small amount of climbing weight for a real chunk of sprint power, and you decide whether the trade is worth it for your event.
Day 10: The Kicker
The inflection point landed on a local hill at day 10.
Anthony does a regular hill repeat session out the back of where he lives. Roughly a 10-minute climb, then a right turn, then a short 30-second kicker to the summit. He has done it hundreds of times. He knows his numbers on the kicker — about 800 watts is normally where he caps out on the short ramp.
That day he hit the kicker fresher than usual. He cranked it. Got home, downloaded the file from his Hammerhead, and saw 850 to 900 watts held across the full 30 seconds, peaking at 900 in the final few. His best short-term power in years.
His words again:
By week four, my 5-second sprint power was up about 5%, which is it's pretty big. And but the repeatability of those efforts seemed to improve for me. Like I could do more intervals of 10 seconds before I started to see a drop off, like kind of a time to exhaustion drop off.
That is the part the data captures. The part it does not is that the sensation was bigger than the numbers — a little extra gear sitting there for short, explosive efforts that simply was not there before.
What Creatine Does Not Do
Honest read: creatine did not change his 20-minute power.
Long climbs over in Wicklow felt the same, maybe a fraction slower because of the extra weight. Heart rate at threshold did not move. Perceived exertion on long efforts was unchanged. That matches the studies. Creatine does not touch aerobic output. It does not improve VO2 max. If anything, on a percentage basis your relative VO2 max drops a touch because your bodyweight has gone up.
So if your event is a pure climb, an ultra-endurance bike-packing race, or anything where every gram matters and the efforts are steady, creatine is the wrong tool. The cost outweighs the benefit. Hill climb specialists are not chasing 5-second sprint power.
For everyone else, the trade looks different.
The Mechanism
The reason any of this works is simple.
Phosphocreatine is the molecule that recharges your ATP — the energy currency your muscles burn during contraction. The natural store in your muscles lasts about 10 to 15 seconds at maximum effort. That is your sprint, your kicker, your bridge to a move. Once it is gone, you drop into the next energy system and your top-end power drops with it.
Supplementing with creatine increases the size of that store. The battery gets bigger. You hold higher power for a few seconds longer before the system runs dry, and the recharge between intervals is faster, which is why the repeatability of short efforts improves.
That is the whole mechanism. There is no aerobic angle. There is no muscle-building angle in the first month. It is a slightly bigger fuel tank for the explosive system.
The Myths Worth Dismissing
A handful of the old myths around creatine are still floating around club rides. They are wrong.
Cramps and dehydration. No. Multiple studies show creatine does not increase cramping or dehydration. Some of the heat research with soldiers and athletes shows fewer heat-related issues on creatine, not more. Anthony rode through a warm patch with long efforts during the experiment. No cramping. No issues. The water held inside the muscle is on your side in the heat, not against you.
Kidney damage. No. The data does not support it in healthy individuals on standard doses. The myth came from creatinine — the waste product — being elevated, which is expected and is not the same as kidney damage. If you have pre-existing kidney disease, talk to your doctor before starting any supplement, including this one.
Steroid relation. None. Creatine has no chemical relationship to anabolic steroids or any hormone. It is naturally occurring, present in your diet through red meat and fish, and allowed by WADA at every level of competitive sport. The only thing to be careful of is contamination, so use a batch-tested, NSF-certified brand.
Loading is required. It is not. Loading saturates the muscles faster. A flat 5g daily gets you to the same end point in 3 to 4 weeks with fewer GI issues. Cycling off is also unnecessary — your body does not downregulate the way it does with caffeine. Some riders cycle off to drop the water weight before a hill climb championship or a hilly stage race. That is a personal call, not a physiological requirement.
Who Should Be Running This Experiment
The discipline matters more than people pretend.
Crit racers, track sprinters, road racers with finishing kicks — the benefit is direct, measurable, and could easily be race-winning. A few extra watts in the last 30 seconds is the difference between first and sixth in most bunch finishes.
Masters cyclists — this is the segment that probably benefits most. Creatine helps preserve muscle mass and strength as you age, and that compounds with the strength training that should already be part of every masters rider's week. If you are over 40 and not on creatine, you are leaving free strength on the table. Our getting faster after 40 guide covers the wider picture.
Vegetarians and vegans — lower baseline creatine stores from diet, so the supplementation effect is bigger. Often the most dramatic responders.
Pure climbers, hill climb specialists, ultra-endurance riders — the trade is harder. The water weight tax is real and the sprint benefit is less relevant to your event. Either skip it during the racing block or restrict to off-season strength phases.
For the wider context on how body weight, fuelling, and performance interact for amateur riders, our weight loss for cyclists guide is the practical companion to this piece.
The Practical Verdict
Anthony stayed on creatine after the experiment. He plans to use it during training blocks where sprint and strength matter, and to come off it ahead of a particularly hilly target event where the water weight would actively hurt. Creatine is a tool. Match it to the work in front of you.
A few small things that will save you trouble:
- Tell your coach. Log the start date in TrainingPeaks so you have a clean before-and-after. The weight gain and the sprint numbers will both show up in the data.
- Use a reputable brand. NSF-certified or batch-tested. Contamination is the only real risk and it is fully avoidable.
- Be patient through week one. Nothing happens for the first 7 to 10 days. The benefits land at saturation, not on day three.
If you want help fitting creatine inside a periodised year, the coaching system is the place to start. For a fast answer on your own protocol, ask the AI coach — trained on every nutrition episode of the podcast.
Listen to the Full Conversation
The full episode is on the podcast — day-by-day experience, the science breakdown, the myth list, and the practical guidance for cyclists at every level. The David Dunne fuelling episode is the natural next listen.