The athlete's bottle is a fixture of training days, and for a stone-aware athlete the question is whether the electrolyte drink is helping or hurting. The data are more reassuring than most people expect — and one detail, the citrate content, turns out to be the interesting part.
The worry about sports drinks is sodium: more sodium in urine means more calcium pulled into urine, and more calcium means more stone risk. The 2009 trial measured exactly that pathway and found urinary calcium unchanged despite the sodium rise — the sodium load in a 2-liter daily intake was within normal urinary parameters and did not shift the calcium ledger. That is the core reassurance: for most athletes, a sports drink consumed as intended does not add stone risk.
The citrate finding adds a useful layer. Citrate is the body's natural crystal inhibitor, and some sports formulas carry meaningful citrate — the 2008 study's Performance drink delivered 19.5 mmol/L and measurably raised urine citrate, the same lever that potassium citrate medication pulls. Not all sports drinks contain citrate at useful levels, and the caveat is calories and fructose: most carbohydrate-heavy sports drinks are too sugary to be daily stone-prevention beverages. The measured position is a middle one.
The stone-relevant drinks keep the ledger simple:
| Food | Oxalate (mg) | Serving | Rating |
|---|---|---|---|
| Water, still | 0 mg | 1 glass | Safe |
| Sparkling water, plain | 0 mg | 1 can | Safe |
| Coconut water | 14 mg | 1 cup | Safe |
| Orange juice | 2 mg | 1 cup | Safe |
| Banana | 6 mg | 1 medium | Safe |
Water remains the base — zero oxalate, zero calories, and the fluid the body is actually losing. The measured values above are context for the wider drink shelf: orange juice and coconut water sit low on oxalate and bring citrate with them, which is why they appear in the stone-friendly hydration discussion. The sports drink is the situational tool: right for long or sweaty sessions, not the daily default.
Three habits cover most of the upside. Use sports drinks when they earn their place — long workouts, heavy sweat, hot conditions — and water the rest of the time. If you choose a sports drink, the citrate content is worth a label check: a formula with meaningful citrate is doing more for stone chemistry than one with none. And keep the sugar in perspective: for a 5K or a gym hour, water plus food covers what the body needs; the sports drink is for the sessions that actually deplete electrolytes.
See how oxalate values are measured and verified on our data methodology page.