Study note • PMID 33594588
Prospective Observational Study of Weight-based Assessment of Sodium Supplements on Ultramarathon Performance (WASSUP).
How to use this page
This note summarizes one study record. Check the participants, methods, results, and limitations before applying it to training.
- • Design signal: controlled study.
- • Population relevance: mixed/unclear athlete specificity.
- • Consistency: single-study evidence.
- • Practical recommendation depends on tolerance, context, and whether it protects training consistency.
ELI5
In plain language
BACKGROUND: Sodium supplements are ubiquitous in endurance running, but their impact on performance has been subjected to much debate. (controlled study; runners).
The abstract doesn’t indicate a clear change in Time to exhaustion, Performance in heat, Cramp risk under the tested conditions. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.
Takeaways
What the abstract suggests
- • Study question: BACKGROUND: Sodium supplements are ubiquitous in endurance running, but their impact on performance has been subjected to much debate.
- • The abstract doesn’t indicate a clear change in Time to exhaustion, Performance in heat, Cramp risk under the tested conditions.
- • Population: runners.
- • Protocol cues (title/abstract): 533 mg • 3.6 min • 4.6 h • 80 km • 250 km.
Protocol
Protocol (as reported)
- • Intervention/exposure: hydration, sodium (vs comparison group).
- • Dose/time/duration cues in abstract/title: 533 mg • 3.6 min • 4.6 h • 80 km • 250 km.
- • Outcomes: Time to exhaustion, Performance in heat, Cramp risk.
- • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.
Fit
Who it may help, and who should be cautious
Who it helps
- • Athletes similar to the study population (runners) working on hydration.
- • Athletes who can measure Time to exhaustion, Performance in heat, Cramp risk with a repeatable workout or time-trial effort.
Who should be cautious
- • If you have symptoms or conditions that make the intervention risky, get professional guidance.
- • If you’re near race day and can’t safely test, defer the experiment.
Methods
What the study actually did
- • Design: controlled study.
- • Population: runners.
- • Comparator: comparison group.
- • Outcomes measured: Time to exhaustion, Performance in heat, Cramp risk.
- • Protocol cues mentioned: 533 mg • 3.6 min • 4.6 h • 80 km • 250 km.
- • Source: PubMed PMID 33594588 (2021) — Sports medicine - open.
Results excerpt
What the abstract reports
“Dehydrated runners were found to have the best performance.”
Note: excerpts are short; for full context, read the paper.
Limits
Limitations and bias
- • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
- • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
- • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
- • This is performance information, not medical advice.
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