Train through a July session and someone will tell you creatine is why your calf locked up. It is one of the most persistent stories in the gym, it has been specifically investigated, and it has not held up.
Here is what creatine actually does to your body water, what the research on athletes training in heat found, and what to do about cramps that is more useful than blaming your scoop.
The short answer
Creatine increases total body water. It does not take water from anywhere.
That distinction is the entire article. The myth assumes creatine pulls fluid out of your bloodstream and into muscle, leaving the rest of you short. That is not the mechanism, and studies looking specifically for the consequences the myth predicts — dehydration, cramping, heat illness — have not found them.
Where the story came from
It came from a reasonable-sounding inference made before anyone had the data.
Creatine is osmotically active. It draws water with it into muscle cells. Early on, that observation got extended into a conclusion nobody had tested: if muscle is holding more water, the rest of the body must be holding less. Add a few high-profile anecdotes from athletes in hot-weather sports, a period when governing bodies and product labels were cautious about advising fluid intake, and the story wrote itself.
The inference was wrong in a specific and checkable way. Creatine does not redistribute a fixed pool of water. It increases the total.
What creatine actually does to your body water
When muscle creatine stores rise, intracellular water rises with them. This is where the first-week scale movement comes from, and it is why creatine users are described as "holding water" — but the water is inside muscle cells, not under the skin.
Critically, research measuring body-water compartments has found that total body water goes up, and that the extracellular compartment — the pool your circulation and your sweat draw on — is not depleted to pay for it. You end up with more fluid on board, distributed with more of it inside muscle.
Some researchers have gone further and proposed that the extra total body water could be mildly protective in the heat, giving you a larger reservoir to sweat from. That idea is supported by some findings and is not settled. We will not oversell it. But it is worth noting that the serious hypothesis in the literature runs in the opposite direction to the gym rumour.
What the research on heat and cramping found
This is the part that should end the conversation.
Creatine has been examined specifically in athletes training and competing in hot conditions, including team-sport athletes through pre-season in summer heat — exactly the population and exactly the setting where the myth predicts trouble. Across that body of work, creatine users have not shown the increases in cramping, heat illness, or dehydration markers that the story requires. Some of that research has reported the opposite: creatine users experiencing cramping and heat-related complaints at the same rate or lower than non-users.
The International Society of Sports Nutrition's position stand on creatine addresses this directly, and its conclusion is that creatine supplementation does not increase the risk of dehydration or muscle cramping. That is a professional body stating a negative finding after the question was investigated, which is a stronger position than the absence of evidence.
The honest qualifiers
- Much of this work is in team-sport and endurance athletes rather than in every possible population and condition.
- "No increased risk" is not the same as "protective." We are not claiming the second.
- None of it changes the fact that training hard in heat requires you to drink, whether or not you take creatine.
So what actually causes cramps?
Less settled than either camp admits, and worth knowing because the popular answer may not be the right one.
There are two main explanations in the literature and they are not mutually exclusive.
The dehydration-and-electrolyte theory. Fluid and sodium losses through heavy sweating alter the environment around the muscle, making it more excitable. This is the folk explanation, and it fits the pattern of cramps appearing late in long, hot sessions.
The neuromuscular fatigue theory. Cramps arise from altered control at the level of the nerve supplying the muscle — a fatigued muscle spindle and Golgi tendon organ imbalance causing sustained involuntary firing. This explanation has gathered considerable support, partly because it accounts for cramps in cool conditions and in well-hydrated athletes, which the first theory struggles with.
The practical read: cramps correlate strongly with doing unusually hard work, for unusually long, in unusual conditions. Which is also when people happen to notice they took creatine that morning.
Why electrolytes belong in the same bottle
Regardless of which cramping theory you favour, the case for replacing what you sweat out is not in dispute.
Sodium is by far the most concentrated electrolyte in sweat, and losses vary enormously between individuals — some men finish a session with a salt-crusted shirt and some don't. Potassium, magnesium, and calcium are present in much smaller amounts. Over a long or hot session, sodium is the one worth thinking about.
That is the logic behind Training Water: creatine monohydrate and electrolytes in the same scoop, in the bottle you were going to carry anyway. Creatine monohydrate supports muscle strength and high-intensity exercise performance when combined with resistance training; electrolytes support normal hydration and fluid balance.* Creatine is a daily maintenance job and hydration is a session job, and they happen to share a container. One scoop, one bottle, nothing else to remember and nothing else in it.
The full panel is on The Monograph — including the part most electrolyte brands would rather you worked out for yourself: 1,000 mg of sodium per scoop, roughly 43% of the daily value. That is a deliberate amount for a hard, hot session, and it is a number to know if you are watching sodium. Read it, then decide.
A hydration protocol that doesn't require a spreadsheet
Four things, in order of how much they matter.
Start the session hydrated. What you drank across the day beats what you drink in the last ten minutes. Pale urine in the morning is a crude but serviceable check.
Drink through the session, guided by thirst and by the conditions. Thirst is a decent regulator for ordinary training. It gets less reliable in long efforts, in heat, and when you are distracted — which is exactly when to be deliberate rather than reactive.
Replace sodium when the session earns it. Long, hot, or heavy-sweating work is where an electrolyte scoop stops being optional. A short indoor session in air conditioning is not that.
Learn your own sweat rate once. Weigh yourself before and after a hard session, without clothes, having emptied your bladder. Every kilogram lost is roughly a litre of fluid. Do it once in summer and once in winter and you will know more about your hydration than any general guidance can tell you.
Who should still be careful
Not because of the cramping myth, but because these are real.
If you have kidney disease, are on prescription medication, or have any medical condition, talk to your doctor before starting creatine or any supplement. If you are training in extreme heat, the risks of heat illness are real and have nothing to do with what is in your bottle — respect acclimatisation, session length, and the conditions.
And if a specific muscle cramps repeatedly, in the same place, without an obvious training explanation, that is worth a conversation with a physician rather than a change of supplement.
The bottom line
Creatine increases total body water rather than redistributing a fixed supply, and the research examining athletes in the heat has not found the dehydration or cramping the folklore promises. The field's professional body has stated as much explicitly.
You still have to drink. You still have to replace sodium when the work warrants it. But you do not have to choose between the best-evidenced supplement in sports nutrition and a summer training block, and you never did.
More in this cluster: what creatine monohydrate actually does and how much creatine per day. Or run the whole system: the Recovery Standard.