# The effect of combining HIIT and dry-land training on strength, technique, and 100-m butterfly swimming performance in age-group swimmers: a randomized controlled trial

PMID: 36636176
Journal: Biology of Sport
Published: 2023 Jan
Authors: Amara S, Hammami R, Zacca R, Mota J, Negra Y, Chortane SG

## Question

Does combining swim HIIT with maximum dry-land strength training improve strength, technique, and 100 m butterfly performance in age-group swimmers?

## Summary

In 22 male national-level adolescent butterfly swimmers, 8 weeks of higher-volume swim HIIT plus maximum strength training improved 100 m butterfly time, technique measures, and bench press and leg extension strength compared with usual lower-intensity, higher-volume training. The protocol is sport-specific and not directly applicable to general home users.

## Population

- 22 national-level male age-group butterfly swimmers.
- Sample size: 22
- Age: 14.1-14.5 years by group mean
- Sex: Male
- Fitness level: Competitive trained swimmers
- Health status: Injury-free before the study

## Methodology

- Randomized controlled trial with active usual-training control
- 8 weeks
- 50 m indoor pool and bodybuilding room
- Randomized and controlled study design.

## Protocol

- Swim HIIT plus maximum strength training.
- Modality: Swimming plus dry-land resistance training.
- Work intervals: Short HIIT <30 s and moderate HIIT 30 s to 2 min.
- Recovery: 1:1 between repetitions; 3 min between sets.
- Sets or repetitions: Swim examples 8 x 50 m and 4 x 100 m; MST 2-5 sets x 3-5 reps.
- Intensity: >85% HRmax for swim HIIT; 85-95% 1RM for MST.
- Frequency: 6 swim sessions/week plus 2 MST sessions/week during weeks 1-6.
- Program length: 8 weeks.
- Progression: Six-week intervention, then two-week taper reducing volume while maintaining intensity.
- Usual swim and core training.
- Modality: Swimming plus general core strength.
- Sets or repetitions: Usual training; low-intensity aerobic example 20 x 100 m.
- Intensity: Mostly <70% HRmax with smaller high-aerobic and HIIT volume.
- Frequency: 6 swim sessions/week plus usual dry-land training.
- Program length: 8 weeks.
- Progression: Two-week taper reducing volume.

## Outcomes

### 100 m time
Status: improved
The experimental group improved 100 m butterfly performance; control did not.

EG 64.13 +/- 1.41 to 61.85 +/- 1.22 s; 3.55%; p=0.001; d=1.81.

### Strength
Status: improved
Bench press and leg extension 1RM improved in the experimental group.

1RM BP +22.11%, p<0.001, d=3.25; 1RM LE +28.23%, p<0.001, d=3.61.

### Technique
Status: improved
Velocity, stroke rate, stroke length, and stroke index improved in the experimental group.

Technique variables improved across first and second 50 m with p<0.05 to p<0.001.

## Practical Insights

- Athlete HIIT may be programmed by distance and HRmax rather than time alone.
- A taper can preserve intensity while reducing volume before performance testing.
- This evidence is useful for sport-specific programming, not general consumer workouts.

## Limitations

- Small all-male athlete sample.
- Multicomponent intervention prevents isolating HIIT effects.
- No adverse-event or attendance details.
- Specific to trained butterfly swimmers.

## Safety And Adherence

- All participants were injury-free before preliminary practice.
- The article did not report intervention adverse events.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/36636176/) (pubmed)
- [DOI](https://doi.org/10.5114/biolsport.2023.110747) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9806757/) (full text)

## Agent Guidance

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