# High-Intensity Interval Training and Sprint-Interval Training in National-Level Rowers

PMID: 34970160
Journal: Frontiers in Physiology
Published: 2021
Authors: Turner KJ, Pyne DB, Périard JD, Rice AJ

## Question

How do short blocks of rowing HIIT and sprint-interval training compare for improving 2000 m ergometer performance in national-level rowers?

## Summary

In national-to-elite rowers, eight sessions of either rowing HIIT or rowing sprint-interval training improved 2000 m ergometer performance, and a second 3-week block added little extra improvement. HIIT appeared better tolerated from athlete feedback.

## Population

- National-to-elite rowers who had competed nationally or internationally in the prior season
- Sample size: 24
- Age: Men 22 +/- 4 years; women 21 +/- 1 years
- Sex: 17 men and 7 women
- Fitness level: Highly trained rowers, habitual training about 12-16 h/week
- Health status: Healthy and injury-free

## Methodology

- Randomized crossover feasibility training study
- Two 3-week blocks plus a 1-week light-training/testing period
- Concept II rowing ergometer training during COVID-19 restrictions
- Randomized and controlled study design.

## Protocol

- Rowing HIIT block.
- Modality: Rowing ergometer.
- Work intervals: 2.5 min.
- Recovery: 2.5 min, with an extra 2.5 min break after interval 4.
- Sets or repetitions: 8 intervals/session; 8 sessions/block.
- Intensity: At least 95% of 2000 m mean power output.
- Session duration: About 60 min including 10 min self-selected warm-up.
- Frequency: 3 sessions/week for 3 weeks, with 2 sessions in the final week.
- Program length: 3-week HIIT block within a 6-week crossover.
- Progression: Participants were instructed to improve mean power output each session; second-block targets used MID 2000 m power.
- Rowing sprint-interval block.
- Modality: Rowing ergometer.
- Work intervals: 30 s all-out.
- Recovery: 60 s between intervals and 5 min after each set.
- Sets or repetitions: 3 sets of 7 intervals/session; 8 sessions/block.
- Intensity: All-out, about 130% of 2000 m mean power output; stroke rate capped at 40 strokes/min.
- Session duration: About 60 min including 10 min self-selected warm-up.
- Frequency: 3 sessions/week for 3 weeks, with 2 sessions in the final week.
- Program length: 3-week SIT block within a 6-week crossover.
- Progression: Participants attempted maximal efforts; training stress was matched to HIIT in pilot work.

## Outcomes

### 2000 m time
Status: improved
Both block orders improved 2000 m ergometer time after 16 high-intensity sessions.

HIIT-SIT -10.6 +/- 3.9 s, -2.5%, p = 0.01; SIT-HIIT -9.0 +/- 5.7 s, -2.2%, p = 0.01

### First block
Status: improved
Most performance improvement occurred after the first 3-week block regardless of method.

First 3 weeks: HIIT-SIT 2000 m -2.0 +/- 0.6%, p = 0.01; SIT-HIIT -1.5 +/- 0.3%, p = 0.01; no significant between-group difference

### 4 min all-out
Status: improved
Four-minute all-out distance improved after the full intervention.

HIIT-SIT +36 +/- 25 m, +3.1%, p = 0.01; SIT-HIIT +33 +/- 27 m, +2.8%, p = 0.01

### Submax HR
Status: mixed
HIIT-SIT produced greater reductions in submaximal HR than SIT-HIIT.

HIIT-SIT reduced HR at steps 4-6 after 16 sessions, p = 0.02; lower HR than SIT-HIIT after eight and 16 sessions, p < 0.05

## Practical Insights

- Eight high-intensity rowing sessions may be enough for short-term performance gains in trained rowers.
- A second consecutive block should be individualized because additional benefit was small and variable.
- HIIT may be preferable to SIT when tolerance and athlete feedback matter.

## Limitations

- No no-training control group
- Feasibility study during COVID-19 restrictions
- Highly trained athlete sample
- Mechanistic measures were limited
- Other training was coach-prescribed and not a standardized lab-only intervention

## Safety And Adherence

- Participants were healthy/injury-free and were given mobility, stretching, and activation exercises to reduce overuse risk.
- Specific adverse-event counts were not reported in the extracted text.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34970160/) (pubmed)
- [DOI](https://doi.org/10.3389/fphys.2021.803430) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8712637/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.