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Moderate- and High-Intensity Inspiratory Muscle Training Equally Improves Inspiratory Muscle Strength and Endurance-A Double-Blind Randomized Controlled Trial.

PMID 33668012 (2021): inspiratory muscle training — Time to exhaustion (study note for endurance athletes).

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

Study note • PMID 33668012

Moderate- and High-Intensity Inspiratory Muscle Training Equally Improves Inspiratory Muscle Strength and Endurance-A Double-Blind Randomized Controlled Trial.

International journal of sports physiology and performance2021 • DOI 10.1123/ijspp.2020-0189
Evidence B70/100
Action 1: Default

Low risk + high feasibility for most athletes.

ELI5

In plain language

Inspiratory muscle training (IMT) produced outstanding results in the physical performance of active subjects; however, little is known about the best training intensity for this population. (randomized trial; n=8 recreational cyclists).

The abstract doesn’t indicate a clear change in Time to exhaustion 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: Inspiratory muscle training (IMT) produced outstanding results in the physical performance of active subjects; however, little is known about the best training intensity for this population.
  • The abstract doesn’t indicate a clear change in Time to exhaustion under the tested conditions.
  • Population: n=8 recreational cyclists.
  • Protocol cues (title/abstract): 11 weeks • 55 min.

Protocol

Protocol (as reported)

  • Intervention/exposure: inspiratory muscle training (vs comparison group).
  • Dose/time/duration cues in abstract/title: 11 weeks • 55 min.
  • Outcomes: Time to exhaustion.
  • 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=8 recreational cyclists) working on breathing.
  • Athletes who can measure Time to exhaustion 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=8 recreational cyclists.
  • Comparator: comparison group.
  • Outcomes measured: Time to exhaustion.
  • Protocol cues mentioned: 11 weeks • 55 min.
  • Source: PubMed PMID 33668012 (2021) — International journal of sports physiology and performance.

Results excerpt

What the abstract reports

IMS increased in CIP and MIP60 groups at the ninth and 13th weeks compared with the sham group (P < .001; beta = 0.99).

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