REF-1051 · Rønnestad & Hansen, 2016 · Journal of Strength and Conditioning Research, · Paper · PubMed
At a fixed power equal to that at VO2max, 30-second work periods with 15-second recoveries gave more work and more time at or above 90% of VO2peak before exhaustion than long work periods at the same power
Key Findings
The 30-second protocol induced a longer time at or above 90% of VO2peak and a longer work duration than work periods of 50% or 80% of the time to exhaustion at that power (p ≤ 0.05).
Thirteen well-trained male cyclists (VO2peak 67 ± 6) rode each format to exhaustion at the minimal power that elicits VO2peak, with recovery lasting half the work period at 50% of that power.
The two long formats did not differ from each other.
Practical Application
If the goal of the session is minutes near VO2max at a given power, short-short (30 s on, 15 s easy) delivers more of them than long reps at that same power.
This holds for a 2:1 work-to-recovery ratio with active recovery; change the recovery to equal or longer and the advantage disappears REF-1049.
Limitations
To exhaustion, which is not how sessions are run; the minutes are not in the abstract (abstract only was read).
At equal MEAN power the picture differs: 20-second reps produced about half the lactate of 4-minute reps (5.2 vs 9.8 mmol/L) and looked like continuous riding (Tschakert 2015, PMID 25729286, six subjects).