REF-1050 · Rønnestad et al., 2015 · Scandinavian Journal of Medicine & Science in Sports, · Paper · PubMed
Over 10 weeks, effort-matched short intervals raised VO2max by 8.7% against 2.6% for long intervals in cyclists
Key Findings
The short-interval group improved VO2max more than the long-interval group: 8.7 ± 5.0% vs 2.6 ± 5.2% (P ≤ 0.05).
Cyclists did two interval sessions a week for 10 weeks as effort-matched short intervals (n = 9) or long intervals (n = 7), with no difference in the total volume of interval or low-intensity training.
Effect sizes for the relative improvement in 30-second, 5-minute and 40-minute all-out power favoured short intervals (0.86–1.54).
Practical Application
When the short-interval session is the demanding kind — short work, shorter active recovery, power above that of a long rep — it is at least as good a VO2max stimulus as classic long reps, and in two small trials better.
"Effort-matched" means the short group rode at a higher power: the result is about that session, not about short reps at the power of long ones.
Limitations
N = 16; performance outcomes are given as effect sizes, not as significant group differences; the exact session formats are not in the abstract (abstract only was read) — for the tested format see REF-045.