Creatine Side Effects is it for Everyone

Started taking creatine almost 2 weeks ago, just for kicks, to see if it would have any benefits. Averaging 4 capsules a day (2.5 grams of creatine monohydrate per pill) for a total of 10 grams a day. Suggested dose is 6 caps a day, 2 with every meal. I’m listening to episode 141 right now where I think they throw shade on creatine but haven’t gotten to that part yet but will update this once I’ve finished the episode. I’ve also increased my protein consumption by 50 grams via ON Whey protein powder. I rarely eat meat.

Around the time I started popping these pills my legs started to pump up and burn out on anything a hair above ftp. Even during the trainer warmups. 2 minutes at around FTP during the warmup and I’m throbbing. Riding below that is fine. No problem.

I’ve been doing TR since August (SSB mid vol and almost done with ShortPowerBuild mid) and my legs have NEVER pumped up, not even during my FTP tests. My form will crumble and my pedal stroke gets chunky with my legs almost seizing up at failure during the ftp test but never pump up prematurely and burn out. Again, this is happening during the warmup for trainer rides. I don’t know what’s going on. I don’t want to stop taking it because I think it’s too soon to bail on the test. I’d like to try it for at least a month before bailing.

I took 2 days rest and then I bailed out of a ride last night half way through in favor of more rest because my quads were roasted despite having done much harder workouts in the recent past.
I got a cold a few days ago so maybe it’s that but that is pretty much gone, energy level is good, just some congestion now.
I also thought it may be the move from virtual power to a stages crank but I turned off the stages and it was the same result. I couldn’t hold the watts without my quads pumping up.


  1. Have you had a similar experience?
  2. Would you say you lean more towards slow twitch or fast twitch? Are you skinny or buff?
  3. What side effects did you experience?
  4. Is there a correlation between creatine and fast/slow twitch muscle fibers.
  5. Is it the creatine that’s causing this mess?

I’ve had 2 leg cramps in my entire life and they were decades ago. I felt one coming on last night when I twisted around in bed to grab my phone. I don’t sweat much at all. I was a horrible sprinter (running) and I never needed to really sprint on the bike. I’m pretty thin and maybe have close to zero fast twitch. I haven’t been outside for a ride in 2 months and I’m wondering if I’ve just now finally lost all of my VO2 gumption.

Or are my shorts too tight? I did get a new pair recently.

39 years old, 323 ftp, 160 lbs, 72.6kg, 4.45 w/kg averaging 400-500 TSS per week, 5 days on for around 6 hours.
Been riding for 20 years off and on but more on than off. 99% off road.

I would be very surprised if many of things you’ve experienced are due to taking creatine.

In my experience, the effects are very, very mild to begin with. This is not like some sort of super drug that is going to transform you. It’s just an amino acid. It should give you a little extra boost in high intensity efforts (sprinting/weight lifting), but I would be surprised if its having such a dramatic effect on your aerobic system.

It can cause you to retain extra water, so that could explain the cramping issues if your hydration hasn’t been on point.

“virtual power to a stages crank” …I’m curious about this. Have you re-tested your FTP with the Stages PM?


I very much doubt the creatine is the problem. As bherbers asks have you re-tested using your Stages?? I went from VP to a Stages and the diff between the two was staggering! Using the Stages i couldn’t hold my VP ftp for more than a few minutes!
Creatine helps me, but it takes a few weeks before I notice any gains.

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Virtual power to stages was off by 40watts for me. Would have anhialated me to work at that level at the time.

Milk sensitivity?

Saw you turned off the stages…stop taking supplements for a week?

Thanks for the responses! Much appreciated. The creatine mention in episode 141 is the last 2 minutes of the episode and all they say is that its effects are negligible. May help during an 8 second anaerobic sprint effort but what benefit does that have when you’re packing on 5 extra pounds of water.

I haven’t retested. I did some intervals last night with and without stages and experienced the same thing. Couldn’t hold the watts. Legs pumped above FTP.

I haven’t retested but have done similar workouts with stages and was able to complete.

My milk consumption is close to zero. Dairy in general is close to nothing. Occasional cheese and yogurt but that’s not new.

After 3 days of rest I just rode my cruiser to lunch and legs started to pump. Never experienced this. Had 3 weeks of consistent trainer loads so maybe I’m just zapped. This suuuuuuuucks. I just wanna ride!!!

What do you mean your legs started to “pump”?

Also, I would retest your FTP with your new power meter, but that’s just me.

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I don’t know how else to describe it. I googled, “Pumped Muscles” and all I get is weight lifting stuff about bigger muscles after a workout. I hesitate to say it’s the lactic acid burn but it might be. It just feels like they are swelling up, I just can’t keep the power down, they stiffen up and my form falls off, a lot like the pumped feeling when lifting weights. I’ve done a handful of workouts at this FTP with and without Stages that haven’t produced this feeling.
I rock climb and ‘pumped’ is a term that is used in every other sentence in a climbers vocabulary. The muscles get ‘pumped’ and your arms almost lock up and you lose mobility. It feels the same.

I know what you mean by pump or pumped. I did a lot of bodybuilding in my 20s so I’m well aware. I never really took the time to really learn and understand what creative was back then, but we all took it cos it ‘pumped’ us up, it made our muscles swell and fill out more as we lifted. I’m not sure why you would want it for cycling I really don’t. To me it’s a waste of time and money.

The book “Endure” by Alex Hutchinson describes a case of heat exhaustion of a high school kid who supplemented with creatine.

I have found consistently over my life of varied sport and training (obstacle racing, weight training, endurance training, triathlon), that during a training phase with creatine supplementation I become susceptible to cramping, and feel a distinct requirement for more water (almost a 40 % increase in fluid consumption over a 3 hour ride), in both upper and lower body. I therefore have modified my supplementation to primarily base and early build phases where unimportant or even no racing occurs in my plan. I do not supplement for more than a 4 week period at a time and off for a minimum of 2 weeks before the next cycle.

This is unique to me and a pattern I have recorded in my logs over the past 10 years. I hope it is helpful to you.


I’ve experienced exactly this, that abnormal pump. While competing in swimming many years ago, I did creatine for a while. I gained a lot of weight (water) and looked bloated in no time, but what was even worse was the horrible pump in my shoulders. The only effect I got from creatine was bloating and this stupid pump that only hindered my aerobic performance.
I have since then never tried it again. When I stopped using it, I quickly lost that bloated weight and stupid pump.


Mine was the same - had to drop my FTP by 30w.

There’s a lot to unpack in your question. I think you need a better ‘experiment’ protocol :slight_smile:


I’m going to go against the grain and say do not supplement with creatine. I was told by a coach that I trust that it has something to do with either adding or secreting water in your muscles (I can’t remember which) in a very harmful way for endurance athletes. I was having similar problems the OP described with leg’s feeling heavy and was talking with my coach at the time. The conversation came up with my coach in terms of a protein powder I was using for recovery (Combat Powder) and said to throw it out and start using an endurance focus one (Scratch, 1st Endurance, etc…).

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Many years ago I used creatine but in low doses in my bottles in races and long rides, I usually raced 3 weekends a month so it was fairly often through the summer. I can’t remember how many grams but it was about a teaspoon in each bottle.

Basically my thinking was that you only use creatine in anaerobic efforts and those tend to really hurt in a race and trigger cramps in my quads, so why not give my muscles that little bit of extra fuel to burn before exhaustion and the pain leading to a cramp?
Everyone is different and it seemed to work for me, it could also have just been a placebo effect and have actually done nothing at all.

Conventional wisdom is that creatine has negligible benefits in cycling, possibly it would help track sprinters but not really endurance riders.

If you are seeing bad side effects cut the creatine and see if your legs improve

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I ended up with serious hamstring tightness when I was taking creatine in college. You have to really increase your hydration. So if you haven’t been drinking enough, this is likely causing your legs to burn.

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FWIW every study I have read stated that creatine supplement was no use for most endurance athletes. There was one notable exception: vegetarians ( guessing you read the same memo). As I am one, I took it. The impact took 3 to 4 weeks to manifest for me and was mild at first. There was a marked increase in strength endurance not strength or power. I could just keep on keeping on. This was without specifically training for that. At the time I was just aimlessly riding. So I am fairly sure that the effect was real. I am almost pure ectomorph. More meat on a butchers pencil.

Your symptoms sound to me more like hydration issues. If it is causing water retention then your electrolytes are going to be out of whack. Which would come into play more at threshold. Also the cramps are a fairly big red flag. Maybe start dropping some of them electrolyebtabs and magnesium.

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Hi mate, I just created an account to comment on this threat.

I’m having the same issue, I feel my legs swallowing like they are pumped with water and I need to stop. I do crossfit and this mainly bothers me on endurance workouts running, rowing or assault bike. It’s so annoying that I need to stop…my legs just shut down on me. My cardio has been always great on long or short workouts.

Did you find any solution that works for you?

Creatine gives me the strength but shuts down my endurance.

Please advise

I take creatine, but I don’t front load the dosage like the back of the labels recommend, just a teaspoon. I don’t have the cramping problems as noted above, but the big thing with creatine is that you REALLY have to up your water intake, I saw this mentioned above.

Why do I take it? I weight / plyometric train 3x a week with a coach who coaches track racers. I use the creatine to help me lift stronger in the gym. I do put on about 5-7lbs of water weight while taking it, but you cut it out before you head into your races. Since you’ve used it to help prime your body to lift heavier weights, you’ll be stronger when you aren’t taking it.

This is how any athlete where power to weight matters does it. Take wrestling (roman greco / college / high school) and MMA fighters. They use it in their off season to help build strength, and then drop it during their cut. I know there were some health problems with some collegiate wrestlers ~20 years ago who tried to cut water weight while taking it, and ending up in the hospital with dehydration issues, but that’s extreme.

I think it makes sense to use it when you are in strength phases of your calendar, and cut it out when you’re approaching events where power / weight matter and where you’re worried about hydration (like a desert race, or hard summer rides). The offseason is not the time to be worrying about power/ weight. I don’t know a single athlete where that matters who does; wrestling, gymnastics, field athletes, etc. Most walk around 5-10llbs heavier than what they compete at.

Another thing is creatine and caffeine fight each other. The former wants water where the latter dehydrates you, so you need to be careful about when you take one of the other, and not together.

Years ago, I used moderate doses of creatine.

Eventually, I began to wake up in the middle of the night with cramp-like sensations in the tibialis anterior. At first, I didn’t connect this with the creatine, but search engines pointed me to supposed links between creatine and compartment syndrome. So I stopped using it and the cramps stopped happening.

The only way that creatine can ruin endurance is by reducing the burn you feel early-on with higher power-outputs which leads to greater metabolic disturbance and swelling of the tissue as a result.

If you were to exert exactly the same power/pace/speed as you had without creatine, there is no plausible mechanism or emphasis for this effect.

Creatine does the following:

  1. Increases muscular endurance for efforts lasting 5-60 seconds, maybe slightly longer.
  2. Increases muscular hydration (a good thing).
  3. Does NOT cause cramping (that’s internet hogwash).
  4. Causes a mild anabolism, as in, promotes growth of muscle via protein synthesis within the muscle.
  5. Increases strength when taken with training for several weeks/months/years.

Caffeine blunts creatine absorption, but not much, and you can just take more creatine to offset this effect.

Not quite. Caffeine’s diuretic effect is actually quite mild and is not a linear dose-response relationship at all. More caffeine ≠ more diuresis. And their effects on water doesn’t explain the inhibitory mechanism, though your recommendation to generally take creatine away from times you’re taking caffeine is sound. Though, there is no harm whatsoever in taking them together.


I stopped using it. Chad talks about the benefits for endurance athletes on one of the podcasts and he basically says it is only useful in a sprint. And it might be a single sprint but I might be wrong. So you get one shot. You might use up its benefits halfway through a ride or race.
I’m not a sprinter so there is no point for me to take it. On top of that, they raise the question, Is it worth it to take it given the added weight you gain from using it for the bit of power it gives you in a sprint? The added weight is something you have to carry for the entirety of a 4 hour ride, if you didn’t have that additional weight wouldn’t you come to the sprint a bit fresher and your wattage perhaps be the same?

Someone just said they gain 5-6 pounds when they are using it. That is massive. If you are an endurance cyclist there doesn’t seem to be any benefit. That’s a lot of additional weight to drag around for a ride.

I should say that I have no idea if it was the creatine that was causing my legs to feel pumped but I haven’t experienced that sensation since. Not once this winter on the trainer and that’s where I was experiencing it the first time around.

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