# Early Adaptations to a Two-Week Uphill Run Sprint Interval Training and Cycle Sprint Interval Training

PMID: 30060478
Journal: Sports
Published: 2018-07-27
Authors: Kavaliauskas M, Jakeman J, Babraj J

## Question

Do two weeks of uphill running SIT and cycle SIT produce similar early physiological and performance adaptations?

## Summary

In recreationally active men, six sessions of 4 x 30 s all-out sprint training over 2 weeks improved ventilatory threshold with both cycling and uphill running. Uphill sprint training also improved time to exhaustion more than cycling, while VO2peak did not significantly change in either training group.

## Population

- Healthy recreationally active men in training and acute-response groups.
- Sample size: 23
- Age: Training study 28 +/- 5 years; acute group 33 +/- 6 years
- Sex: Men
- Fitness level: Recreationally active, at least 3 sessions/week of moderate exercise
- Health status: Healthy

## Methodology

- Randomized controlled training study with a separate acute crossover response group
- 2 weeks
- Human performance laboratory and outdoor 10% hill
- Randomized and controlled study design.

## Protocol

- Cycle SIT or uphill sprint training.
- Modality: Cycling or uphill running.
- Work intervals: 30 s all-out.
- Recovery: 4 min active recovery.
- Sets or repetitions: 4.
- Intensity: All-out; cycling against 7.5% body mass or uphill on 10% slope.
- Session duration: 18 min excluding warm-up/cool-down.
- Frequency: 3 sessions/week.
- Program length: 2 weeks.
- Progression: None reported.
- Control or alternate SIT modality.
- Modality: Usual activity control; cycling or uphill running comparator.
- Work intervals: For active comparators, same 30 s all-out intervals.
- Recovery: For active comparators, same 4 min active recovery.
- Sets or repetitions: 4 for active comparators.
- Intensity: Control maintained usual activity; active comparators all-out.
- Session duration: Control not applicable.
- Frequency: Control usual activity.
- Program length: 2 weeks.
- Progression: None.

## Outcomes

### VO2peak
Status: no clear change
VO2peak did not significantly change after either SIT or UST.

SIT 49 +/- 7 to 49 +/- 7; UST 48 +/- 4 to 50 +/- 6 mL/kg/min; p>0.05.

### TTE
Status: mixed
TTE improved significantly after UST but not after SIT, and the change favored UST.

UST 495 +/- 40 to 551 +/- 15 s p=0.014; SIT 613 +/- 135 to 634 +/- 118 s p=0.07; change difference p=0.04.

### Ventilatory threshold
Status: improved
Both SIT and UST improved ventilatory threshold similarly.

SIT 1.94 +/- 0.45 to 2.23 +/- 0.42 L/min; UST 2.04 +/- 0.40 to 2.33 +/- 0.34 L/min; p<0.005 for both.

## Practical Insights

- Uphill running SIT may be a lower-equipment alternative to cycling SIT for prepared users.
- Ventilatory threshold may respond before VO2peak in very short SIT blocks.
- Matching work/rest timing does not guarantee total-work matching across modalities.

## Limitations

- Small sample size.
- Men only.
- Training background not controlled.
- Only two weeks of training.
- Protocols not matched for total work.

## Safety And Adherence

- Adverse events and injuries were not reported.
- Participants were healthy and recreationally active.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/30060478/) (pubmed)
- [DOI](https://doi.org/10.3390/sports6030072) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162401/) (full text)

## Agent Guidance

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