REF-695 · Iaia & Bangsbo, 2010 · Scandinavian Journal of Medicine & Science in Sports, · Paper · PubMed
Speed-endurance training keeps oxidative capacity and improves 30 s–4 min performance in trained athletes, even when total training volume is reduced
Key Findings
In already trained subjects, speed-endurance training (bouts at near-maximal intensity) maintained oxidative capacity and improved intense short-duration / repeated high-intensity performance lasting 30 s to 4 min — despite a reduction in training volume.
Combined with a basic training volume that includes some aerobic high-intensity sessions, it also helped performance in longer events (e.g. 40 km cycling, 10 km running). Team-sport athletes can benefit too.
The gains did not appear to depend on changes in VO2max, muscle substrate levels, glycolytic/oxidative enzyme activity or pH-regulating transport proteins.
They appear related to lower energy expenditure during submaximal exercise and higher expression of muscle Na+,K+ pump α-subunits, which may delay fatigue during intense exercise.
Practical Application
Iaia & Bangsbo's review: in trained athletes, near-maximal speed-endurance bouts kept oxidative capacity and improved 30 s–4 min performance even with less total volume; with a normal aerobic base they also helped 40 km cycling and 10 km running — worth including for any discipline with periods of intense effort.
Inference, not tested here: this makes speed-endurance sessions a candidate for holding fitness in lower-volume phases (taper, busy weeks); keep the doses small and high-quality.
Limitations
Narrative synthesis; "maintenance on reduced volume" refers to the reviewed intervention periods, not indefinitely.
How this entry was checked and changed
Content correction 2026-09-27
Title "a few weeks … maintain performance when volume is cut sharply" -> the abstract's claim: oxidative capacity maintained and 30 s–4 min performance improved despite reduced volume.
Added the abstract's longer-event effect (with an aerobic base), the null VO2max/enzyme findings and the proposed mechanisms (submaximal economy, Na+,K+ pump).
Taper/busy-week use and "small, high-quality doses" relabelled as inference; Sport "conditioning" -> "running, cycling, general".