# Effects of self-paced high-intensity interval training and moderate-intensity continuous training on the physical performance and psychophysiological responses in recreationally active young adults

PMID: 34937964
Journal: Biology of Sport
Published: 2020-12-31
Authors: Soylu Y, Arslan E, Sogut M, Kilit B, Clemente FM

## Question

Does an 8-week self-paced running HIIT program improve physical performance and psychophysiological responses more than self-paced MICT in recreationally active young adults?

## Summary

In 28 recreationally active young men, 8 weeks of self-paced running HIIT and self-paced moderate continuous running both improved body composition, sprinting, jumping, Yo-Yo intermittent recovery performance, estimated VO2max, repeated sprint ability, and change-of-direction performance. HIIT produced larger gains in YYIRTL-1, estimated VO2max, repeated sprint ability, and T-drill performance, and participants reported higher perceived exertion and higher enjoyment than MICT.

## Population

- Twenty-eight recreationally active young male adults performing team sports such as soccer, basketball, and handball; 14 in HIIT and 14 in MICT after 4/32 initial participants were excluded.
- Sample size: 28
- Age: 21.1 +/- 1.6 years
- Sex: 28 male participants
- Fitness level: Recreationally active; <3 training units/week and <180 min/week for at least 2 years
- Health status: Young apparently healthy team-sport participants; no additional inclusion or exclusion criteria were applied

## Methodology

- Two-group parallel training intervention with group allocation based on aerobic fitness rankings
- 8 weeks of training within a 10-week testing/training/testing design
- Indoor basketball court testing and 400-m athletics track training
- Controlled study design.

## Protocol

- Self-paced running HIIT.
- Modality: Track running.
- Work intervals: 30 sec high-intensity self-paced running.
- Recovery: 30 sec passive rest.
- Sets or repetitions: 2 x 12 reps in weeks 1-2; 2 x 16 in weeks 3-4; 2 x 20 in weeks 5-6; 2 x 24 in weeks 7-8.
- Intensity: Self-paced, freely adjusted without intensity feedback.
- Session duration: 24-48 min main set plus 15-min warm-up.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: Interval repetitions increased every 2 weeks.
- Self-paced MICT.
- Modality: Continuous track running.
- Work intervals: Continuous running.
- Sets or repetitions: One continuous run.
- Intensity: Self-paced, freely adjusted without intensity feedback.
- Session duration: 24 min in weeks 1-2; 32 min in weeks 3-4; 40 min in weeks 5-6; 48 min in weeks 7-8; plus 15-min warm-up.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: Continuous running duration increased every 2 weeks and was fixed at twice HIIT training time.

## Outcomes

### Aerobic fitness
Status: improved
Both groups improved YYIRTL-1 and estimated VO2max, with greater improvements in HIIT.

YYIRTL-1: HIIT +44.3% vs MICT +30.2%, p=0.001 between groups; VO2max: HIIT +9.2% vs MICT +5.8%, p=0.001 between groups

### Repeated sprint and change-of-direction performance
Status: improved
Both groups improved, with HIIT superior for RSA total and T-drill.

RSA total: HIIT -9.2% vs MICT -6.0%, p=0.009; T-drill: HIIT -9.8% vs MICT -5.3%, p=0.042

### Enjoyment and perceived exertion
Status: improved
HIIT was perceived as harder but also more enjoyable than MICT.

RPE 17.2 +/- 0.6 vs 13.1 +/- 1.1, p<0.01; PACES 101.3 +/- 5.3 vs 80.8 +/- 4.6, p<0.01

### Body composition, sprinting, and jumping
Status: mixed
Both interventions improved anthropometry, sprinting, and jumping, but between-group differences were mostly absent.

Within-group improvements p<=0.05; no significant between-group differences for body weight, BMI, most sprints, jumps, or triple-hop distance

## Practical Insights

- Self-paced 30-sec running intervals can be a practical, enjoyable format for young recreational team-sport participants.
- HIIT may provide larger aerobic, repeated sprint, and change-of-direction improvements than time-matched MICT in this narrow population.
- Use caution applying the results to women, older adults, sedentary users, or users with injury risk.

## Limitations

- No non-exercise control group.
- Group allocation was based on aerobic fitness ranking rather than clear randomization.
- Male-only, young, recreationally active team-sport sample.
- Dietary intake was not controlled.
- VO2max was estimated from YYIRTL-1 rather than directly measured.

## Safety And Adherence

- Four of 32 initial participants were excluded due to injuries, nonattendance, or dropout; injury details and causality were not specified.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34937964/) (pubmed)
- [DOI](https://doi.org/10.5114/biolsport.2021.100359) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8670818/) (full text)

## Agent Guidance

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