'Just drink more water' doesn't always fix cramps
Cramps during or after a workout get automatically blamed on not drinking enough water, but research into what actually causes muscle cramps paints a more complicated picture. Besides dehydration, electrolyte balance matters — sodium, potassium, magnesium, and calcium, all lost through sweat along with water — and just topping up with plain water without electrolytes can sometimes make things worse by further diluting the sodium left in your blood.
A separate line of research ties cramps not to fluid balance at all, but to neuromuscular fatigue: overworked, tired muscle fibers become more prone to involuntary contractions regardless of hydration status — which explains why cramps happen more often toward the end of long or unusually intense sessions even in people who drank plenty of water.
Practical takeaway: if cramps keep happening despite drinking enough water, it's worth looking at electrolytes in your diet overall (not just during the workout) and whether your training volume has outpaced your current fitness level — rather than just drinking more.