Study note • PMID 21253973
No fluid overload in male ultra-runners during a 100 km ultra-run.
Worth trying if it fits your goal and context.
ELI5
In plain language
We investigated the change in body composition and hydration status in 27 male ultra-runners during a 100 km ultra-run. (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: We investigated the change in body composition and hydration status in 27 male ultra-runners during a 100 km ultra-run.
- • 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): 100 km.
Protocol
Protocol (as reported)
- • Intervention/exposure: hydration, fluid.
- • Dose/time/duration cues in abstract/title: 100 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 helps, and who should skip it
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 skip
- • 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.
- • Outcomes measured: Time to exhaustion, Performance in heat, Cramp risk.
- • Protocol cues mentioned: 100 km.
- • Source: PubMed PMID 21253973 (2011) — Research in sports medicine (Print).
Results excerpt
What the abstract reports
“Body mass decreased by 1.9 kg, haematocrit decreased, plasma [Na(+)] remained unchanged, and urinary specific gravity and plasma volume increased.”
Note: excerpts are short; for full context, read the paper.
Limits
Limitations & 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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