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Evidence of parasympathetic hyperactivity in functionally overreached athletes.

PMID 24136138 (2013): taper — Time-trial performance (study note for endurance athletes).

Last updated/Feb 23, 2026, 10:34 PM

Study note • PMID 24136138

Evidence of parasympathetic hyperactivity in functionally overreached athletes.

Medicine and science in sports and exercise2013 • DOI 10.1249/MSS.0b013e3182980125
Evidence B71/100
Action 1: Default

Low risk + high feasibility for most athletes.

ELI5

In plain language

We analyzed HR variability (HRV) to detect alterations in autonomic function that may be associated with functional overreaching (F-OR) in endurance athletes. (randomized trial; n=13 trained triathletes).

The abstract reports an association involving Time-trial performance (not necessarily causation). Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: We analyzed HR variability (HRV) to detect alterations in autonomic function that may be associated with functional overreaching (F-OR) in endurance athletes.
  • The abstract reports an association involving Time-trial performance (not necessarily causation).
  • Population: n=13 trained triathletes.
  • Protocol cues: abstract may omit dose/timing; use the full paper to replicate accurately.

Protocol

Protocol (as reported)

  • Intervention/exposure: taper (vs control group).
  • Dose/time/duration: abstract doesn’t include enough detail; use the full paper’s methods section.
  • Outcomes: Time-trial performance.
  • 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 (n=13 trained triathletes) working on tapering.
  • Athletes who can measure Time-trial performance 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: randomized trial.
  • Population: n=13 trained triathletes.
  • Comparator: control group.
  • Outcomes measured: Time-trial performance.
  • Source: PubMed PMID 24136138 (2013) — Medicine and science in sports and exercise.

Results excerpt

What the abstract reports

Using daily HRV recordings averaged over each week, this study detected a progressive increase in the parasympathetic modulation of HR in endurance athletes led to F-OR.

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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Sources