# Low and high volume sprint interval training combined with resistance training: dose-response effects and short-term training cessation in inactive males

PMID: 30974768
Journal: Sports
Published: 2019 Apr 10
Authors: O'Connor D, Malone JK

## Question

Do low- and high-volume sprint interval training programs combined with resistance training differ in aerobic, metabolic, perceptual, and detraining responses in inactive men?

## Summary

In a small study of inactive men, 6 weeks of low- or higher-volume cycling sprint intervals plus weekly resistance training improved VO2peak, with no clear advantage of higher volume immediately after training. After 3 weeks without training, the higher-volume group appeared to maintain VO2peak better, but the sample was very small and resistance training confounded pure SIT effects.

## Population

- Healthy inactive males completing low-dose or high-dose SIT plus resistance training.
- Sample size: 19
- Age: Completers: LDG 35 +/- 7.1 years; HDG 38 +/- 7.5 years
- Sex: Male
- Fitness level: Inactive, no more than 1 hour structured exercise per week
- Health status: Healthy by PAR-Q and absence of cardiovascular, metabolic, or hormonal disease

## Methodology

- Between-groups intervention with control, training, and cessation phases
- 6-week control period, 6-week intervention, and 3-week cessation
- Supervised laboratory cycle sprint and resistance-training sessions
- Controlled study design.

## Protocol

- Low-dose SIT plus resistance training.
- Modality: Cycle ergometer sprint intervals plus weekly resistance training.
- Work intervals: 6 seconds.
- Recovery: 18 seconds unloaded cycling between sprints; 2 minutes between sets.
- Sets or repetitions: 2 sets of 5 sprints per SIT session.
- Intensity: All-out against 7.5% body weight resistance.
- Session duration: SIT session included 2 minute warm-up, sprint sets, and 2 minute cooldown.
- Frequency: 2 SIT sessions and 1 resistance session per week.
- Program length: 6 weeks.
- Progression: Low-dose group stayed at 2 sets per session.
- High-dose SIT plus resistance training.
- Modality: Cycle ergometer sprint intervals plus the same weekly resistance training.
- Work intervals: 6 seconds.
- Recovery: 18 seconds unloaded cycling between sprints; 2 minutes between sets.
- Sets or repetitions: 4 sets weeks 1-2, 5 sets weeks 3-4, 6 sets weeks 5-6.
- Intensity: All-out against 7.5% body weight resistance.
- Session duration: Longer SIT session than low-dose group because of extra sets.
- Frequency: 2 SIT sessions and 1 resistance session per week.
- Program length: 6 weeks.
- Progression: Progressed from 4 to 6 sprint sets per SIT session.

## Outcomes

### VO2peak
Status: improved
Both low- and high-dose groups improved VO2peak after 6 weeks.

Group x time p=0.013; LDG +16%, 32.3 to 37.6, p<0.001; HDG +11%, 34.4 to 38.1, p<0.001; no between-group difference at post p=0.381.

### Cessation VO2peak
Status: mixed
VO2peak declined after cessation in the low-dose group but was maintained in the high-dose group.

3POST: LDG -11%, 37.6 to 33.4, p=0.03; HDG +3%, 38.1 to 39.2, p=0.09; between-group p=0.002.

### RPE and enjoyment
Status: improved
Perceived exertion decreased and enjoyment increased across training.

RPE session 1 to 12: LDG 18 to 15, p=0.017; HDG 17 to 14, p=0.023. Enjoyment: LDG 5 to 7, p=0.039; HDG 6 to 7, p<0.001.

### Blood pressure
Status: improved
Diastolic blood pressure decreased after training in both groups.

DBP at post: LDG -9%, p=0.006; HDG -5%, p=0.02; SBP no significant change.

## Practical Insights

- Very short 6-second all-out cycling sprints can improve VO2peak when combined with weekly resistance training.
- Higher volume did not clearly increase immediate VO2peak gains but may support retention after short cessation.
- Because resistance training was included, the study is not pure SIT evidence.

## Limitations

- Very small final sample of 13.
- About 30% attrition before completion.
- Male-only inactive sample.
- Concurrent resistance training confounds SIT-specific effects.
- No fully nontraining randomized control during the intervention phase.

## Safety And Adherence

- Six of 19 recruited participants withdrew before completion due to illness or time constraints.
- The discussion reported withdrawals were not due to protocol intolerability.
- No specific adverse events were reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/30974768/) (pubmed)
- [DOI](https://doi.org/10.3390/sports7040085) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524361/) (full text)

## Agent Guidance

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