Study note • PMID 29910346
The Effects of Sleep Extension on Sleep, Performance, Immunity and Physical Stress in Rugby Players.
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: athlete/trained context.
- • Consistency: single-study evidence.
- • Practical recommendation depends on tolerance, context, and whether it protects training consistency.
ELI5
In plain language
(1) Background: The purpose of the present study was to examine the efficacy of sleep extension in professional rugby players. (controlled study; elite athletes).
Effects on Sleep quality, Recovery speed are mixed or unclear from the abstract alone. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.
Takeaways
What the abstract suggests
- • Study question: (1) Background: The purpose of the present study was to examine the efficacy of sleep extension in professional rugby players.
- • Effects on Sleep quality, Recovery speed are mixed or unclear from the abstract alone.
- • Population: elite athletes.
- • Protocol cues (title/abstract): 07 m.
Protocol
Protocol (as reported)
- • Intervention/exposure: sleep extension (vs comparison group).
- • Dose/time/duration cues in abstract/title: 07 m.
- • Outcomes: Sleep quality, Recovery speed.
- • 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 (elite athletes) working on sleep.
- • Athletes who can measure Sleep quality, Recovery speed 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: elite athletes.
- • Comparator: comparison group.
- • Outcomes measured: Sleep quality, Recovery speed.
- • Protocol cues mentioned: 07 m.
- • Source: PubMed PMID 29910346 (2018) — Sports (Basel, Switzerland).
Results excerpt
What the abstract reports
“In addition, a small decrease in cortisol (−18.7%; +/- 26.4%) and mean reaction times (−4.3%; +/- 3.1%) was observed following the intervention, compared to the control.”
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.
Adaptive AI coach for iPhone
Meet your adaptive AI coach.
Tell your coach what you are training for. It builds the plan, follows the work you complete, and adapts upcoming training when recovery, your schedule, or real life changes.
Keep going
Performance Science Lab
Research summaries for endurance athletes, with study context, practical protocols, and clear limitations.
Sleep performance research
Sleep affects recovery, alertness, and training quality. Start with routines you can repeat and judge trends over time.
Sleep extension for athletes: what changes, and how to do it
Evidence-informed protocol: Sleep extension for athletes: what changes, and how to do it. Practical steps, who it helps, and what to watch out for.