REF-998 · Hov et al., 2022 · Scandinavian Journal of Medicine & Science in Sports, Vol. · Paper · PubMed

Aerobic high-intensity intervals are superior to improve VO2max compared with sprint intervals in well-trained men

B+moderate evidenceMeasured on trained to highly trained athletesWritten before October 2026, being re-checked

Forty-eight aerobically well-trained men were randomised to one of three interval protocols performed 3× week for 8 weeks: 4 × 4 min at ~95% maximal aerobic speed (HIIT), 8 × 20 s at ~150% MAS, or 10 × 30 s at ~175% MAS (both sprint interval training, SIT).

VO2max rose more after the 4 × 4 min protocol than after either sprint protocol, with a larger rise in stroke volume (O2-pulse). Anaerobic capacity rose only after 8 × 20 s. 3000-m performance improved in all three groups, with HIIT improving more than 10 × 30 s. The authors conclude that HIIT improves VO2max more than SIT and should typically be the chosen interval format.

Participants

n=48 aerobically well-trained men (23 ± 3 years), randomised to three groups. Baseline VO2max and group sizes are not given in the abstract.

Protocol

3× week for 8 weeks, running.
HIIT: 4 × 4 min, each bout at ~95% of maximal aerobic speed (MAS), with 3 min of active recovery between.
SIT 8 × 20 s: each sprint at ~150% MAS, 10 s of passive rest between.
SIT 10 × 30 s: each sprint at ~175% MAS, 3.5 min of active recovery between.
Outcomes: VO2max, stroke volume (O2-pulse), anaerobic capacity (maximal accumulated oxygen deficit), 3000-m and 300-m performance.

Key Results

VO2max: rose 6.5 ± 2.4% with HIIT 4 × 4 min (p < 0.001) versus 3.3 ± 2.4% with SIT 8 × 20 s (p < 0.001) and no significant change with SIT 10 × 30 s (n.s.); the HIIT gain was larger (p < 0.001).
Stroke volume (O2-pulse): up 8.1 ± 4.1% with HIIT (p < 0.001), against 3.8 ± 4.2% with SIT 8 × 20 s (p < 0.01) and a non-significant change with SIT 10 × 30 s (n.s.); the HIIT increase was larger (p < 0.05).
Anaerobic capacity: increased after SIT 8 × 20 s (p < 0.05), not after HIIT or SIT 10 × 30 s.
3000-m performance: every group got faster — by 5.9 ± 3.2% with HIIT, 4.1 ± 3.7% with SIT 8 × 20 s and 2.2 ± 2.2% with SIT 10 × 30 s — and the HIIT gain exceeded that of SIT 10 × 30 s (p < 0.05). The abstract reports no difference between HIIT and SIT 8 × 20 s for 3000 m.
300-m performance: improved within the SIT 8 × 20 s group (4.4 ± 2.0%) and within the SIT 10 × 30 s group (3.3 ± 2.8%).

Practical Application

"Long intervals or sprints to raise VO2max when I am already fit?" In 48 aerobically well-trained men randomised to three interval formats, 3× week for 8 weeks (between-group comparison, no control group), 4 × 4 min at ~95% of maximal aerobic speed raised VO2max by 6.5 ± 2.4%, 8 × 20 s at ~150% by 3.3 ± 2.4%, and 10 × 30 s at ~175% not significantly. VO2max still moved in a well-trained group, and the aerobic format moved it most.
Performance followed less cleanly: 3000-m time improved in all three groups, and the 4 × 4 group was significantly ahead only of the 10 × 30 s group. A larger VO2max gain did not translate into a clearly larger 3000-m gain over the 8 × 20 s format.
The sprint formats bought what the long format did not: anaerobic capacity (8 × 20 s) and 300-m speed (both sprint groups).
What was not measured or not reported in the abstract: thresholds, running economy, the other training done, individual responses.
Not from this paper; the base's own practice: how to shape a VO2max interval is SYNTH-33; where sprint formats belong is SYNTH-46.

Limitations

No non-interval control group; the comparison is between formats only.
Men, 23 ± 3 years, running; baseline VO2max, group sizes and background training are not in the abstract.
The formats are not matched for work or time, so "format" bundles intensity, duration and recovery.
3000-m performance did not differ significantly between the 4 × 4 min and 8 × 20 s groups in the abstract.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level

randomised, n=48 across three arms; no control group