Energy, water and foot strike
· 1 min read
First published:
Research through: 2 October 2026
Two newly indexed papers add useful boundaries rather than a new prescription: a two-runner 322 km case study quantifies exceptional energy expenditure and water turnover, while a 738-runner cohort found no association between rearfoot versus non-rearfoot pattern and one-year running-injury risk.
Targeted PubMed coverage with a one-day overlap for late indexing; not an exhaustive search of every database or preprint server.
Topics: Training, Fueling
Finding
In two runners completing 322 km, doubly labeled water measured total race energy expenditure of 29,376 and 38,909 kcal and water turnover of 35.2 and 47.5 L; the study does not establish 100K intake targets.
Limitations: Two cases in a much longer event; absolute expenditure and water turnover reflect event duration, rest time, environment and individual physiology and are not prescriptions.
Evidence level: Emerging evidence
- Total Energy Expenditure and Water Turnover During a 322 Km Mountain Ultramarathon (opens in a new tab) · · Research from this week
Finding
In 738 runners followed for one year, rearfoot versus non-rearfoot footfall pattern was not associated with overall running-related injury risk or injury location.
Limitations: Secondary observational analysis; no randomized foot-strike retraining and no proof that changing strike pattern cannot affect symptoms or loading in a specific runner.
Evidence level: Moderate evidence
Interpretation
Treat the 322 km values as context, not intake targets. Keep fueling and hydration individualized, and do not change foot strike solely to prevent injury. No 100K protocol, safety rule or dose changes this week.
Further reading: current guides
Update history
- · 2 October catch-up candidate prepared from targeted evidence review; no protocol change proposed.
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