Hmm, the story doesn’t hold together mechanistically, and your skepticism is right.
The key tell is the language Peterson used: “baseline level was already high” and dosing “made the levels unsafe.” That’s almost certainly serum creatinine, not creatine, the kidney function marker. Creatine supplementation reliably raises serum creatinine because creatine spontaneously degrades to creatinine, which is then filtered by the kidney. This is a well-documented benign lab artifact, not evidence of kidney dysfunction or a cramping risk. There’s no clinical mechanism connecting elevated serum creatinine to exercise associated muscle cramps (EAMC).
If they actually meant intramuscular creatine (phosphocreatine + free creatine), there’s no routine clinical test for that, and skeletal muscle saturation is self-limiting around 150-160 mmol/kg dry mass. The excess gets excreted. You can’t supplement past saturation into a pathologic state. The “we tested his levels and they were too high” framing doesn’t map onto any real measurement that would predict cramping to my knowledge.
What he actually described, full-body cramping during preseason conditioning in September, severe enough that they couldn’t get a vein for an IV, sounds far more consistent with exertional heat illness, exertional rhabdomyolysis, or a precipitating exertional syndrome (various myopathies) than a supplemental creatine reaction. The fact that bloodwork pointed to “creatine levels” as the answer also doesn’t make sense.
On the cramping mechanism more generally, there’s another issue here.The neuromuscular fatigue model s the best-supported framework for EAMC. Multiple prospective cohort studies failed to show that dehydration or electrolyte loss predicts cramping, and cramps can be experimentally induced in euhydrated , electrolyte-replete people. Dehydration/electrolyte stuff is largely a holdover that survives because the bedside fix (fluids, pickle juice, salt) often coincides with the natural resolution of the cramp or works through reflex mechanisms unrelated to systemic electrolyte status.
The creatine-and-cramping evidence is the opposite of what the ESPN narrative implies. From our creatine article:
Creatine also does not increase the risk of dehydration. In fact, creatine seems to reduce the risk of cramping when studied directly. In one study of a Division-1 football players taking supplemental creatine or placebo, those taking creatine had less cramping, muscle tightness, strains, and total injuries compared to the placebo group. [12] In a group of individuals with kidney disease on dialysis, patients who frequently reported muscle cramps were given creatine before dialysis and it reduced their frequency of muscle cramps by 60%. [13]
I’m not aware of a published case where high-quality monohydrate was causally tied to EAMC with a defensible mechanism.
What’s most likely going on with Peterson:
- He had a real exertional event in September (probably heat-related or exertional rhabdo-adjacent).
- The medical team did bloodwork, found elevated creatinine (expected with supplementation), and either misinterpreted it or had it misinterpreted by the patient/reporter.
- Stopping creatine coincided with finishing preseason conditioning, acclimatizing, recovering from whatever the initial insult actually was, and adjusting training load. By late season he was logging 30+ minute games. In my opinion, it was likely “preseason load + heat + something idiosyncratic resolved with time and load management,” not “creatine.”
Wish ESPN would’ve contacted me haha!
-Jordan
