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Study note

High-intensity Interval Training Shock Microcycle Improves Running Performance but not Economy in Female Soccer Players.

PMID 33307555 (2021): endurance, interval — VO₂max, Lactate threshold (study note for endurance athletes).

Updated Jul 22, 2026

Read the study note

Study note • PMID 33307555

High-intensity Interval Training Shock Microcycle Improves Running Performance but not Economy in Female Soccer Players.

International journal of sports medicine2021 • DOI 10.1055/a-1302-8002

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: randomized trial.
  • Population relevance: mixed/unclear athlete specificity.
  • Consistency: single-study evidence.
  • Practical recommendation depends on tolerance, context, and whether it protects training consistency.

ELI5

In plain language

This study aimed to evaluate the effect of high-intensity interval training shock microcycles (HIIT(SM)) on endurance, running economy and change of direction economy in female soccer players. (randomized trial; elite participants).

The abstract doesn’t indicate a clear change in Lactate threshold 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: This study aimed to evaluate the effect of high-intensity interval training shock microcycles (HIIT(SM)) on endurance, running economy and change of direction economy in female soccer players.
  • The abstract doesn’t indicate a clear change in Lactate threshold under the tested conditions.
  • Population: elite participants.
  • Protocol cues (title/abstract): 13 days • 20m • 10m.

Protocol

Protocol (as reported)

  • Intervention/exposure: endurance, interval (vs comparison group).
  • Dose/time/duration cues in abstract/title: 13 days • 20m • 10m.
  • Outcomes: VO₂max, Lactate threshold.
  • 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 participants) working on endurance.
  • Athletes who can measure VO₂max, Lactate threshold 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: randomized trial.
  • Population: elite participants.
  • Comparator: comparison group.
  • Outcomes measured: VO₂max, Lactate threshold.
  • Protocol cues mentioned: 13 days • 20m • 10m.
  • Source: PubMed PMID 33307555 (2021) — International journal of sports medicine.

Results excerpt

What the abstract reports

There was no significant interaction (groupxtime) for running economy and change of direction economy.

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.

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