Superior performance improvements in elite cyclists following short-interval vs effort-matched long-interval training.
Level 3 - non-randomized controlled study
Controlled comparative trial without explicit mention of randomization in abstract
PubMed 31977120 · doi:10.1111/sms.13627
What was done
Eighteen elite cyclists (mean VO2max 73 ± 4 mL·min⁻¹·kg⁻¹) completed 3 weeks of training (9 sessions total) consisting of either short intervals (SI; n = 9; 3 series of 13 × 30-second work intervals with 15-second recovery, 3 minutes between series) or effort-matched long intervals (LI; n = 9; 4 × 5-minute work intervals with 2.5-minute recovery). Total training volume and intensity distribution were matched between groups. Measured outcomes were peak aerobic power output, VO2max, fractional utilization of VO2max and power output at 4 mmol·L⁻¹ blood lactate, and mean power output during a 20-minute cycling test.
What was found
SI produced greater relative improvements than LI in peak aerobic power output (3.7 ± 4.3% vs -0.3 ± 2.8%, P < .05), fractional utilization of VO2max at 4 mmol·L⁻¹ lactate (3.0 ± 5.8 vs -3.5 ± 2.7 percentage points, P < .05), power output at 4 mmol·L⁻¹ lactate (2.0 ± 6.7% vs -2.8 ± 3.4%, P < .05), and 20-minute cycling test power output (4.7 ± 4.4% vs -1.4 ± 2.2%, P < .01). Neither group showed a significant difference in VO2max change.
Why it matters
In highly trained endurance athletes where physiological adaptations often plateau, short work-relief intervals appear superior to traditional multi-minute intervals for boosting threshold and sustained power output.
Limits
The sample size was very small (n = 18 total) and the intervention duration was brief (3 weeks). The abstract does not specify whether group allocation was randomized or describe participant sex/gender. Results from elite athletes cannot be directly generalized to recreational cohorts.
Cited by
- partial Studies by Rønnestad and Lundby found that elite cyclists with baseline VO2 max values of 72–73 mL/kg/min who incorporated 30-second repeated sprints experienced greater improvements in 20-minute time-trial performance and VO2 max compared to effort-matched continuous 5-minute HIIT repeats.