Greater improvement in aerobic capacity after a polarized training program including cycling interval training at low cadence (50–70 RPM) than freely chosen cadence (above 80 RPM)
Participants
n=24 well-trained female cyclists (well-trained by maximal oxygen uptake and training experience) — the sum of two groups of 12: POLLC (low cadence) and POLFC (freely chosen cadence)
Protocol
8 weeks of polarized training (POL), identical for both groups, differing only in the cadence used during SIT and HIIT:
| Component | Both groups |
|---|---|
| SIT | 8-12 repetitions × 30 s at maximal intensity |
| HIIT | 4-6 repetitions × 4 min at 90-100% maximal aerobic power (MAP) |
| LIT | 150-180 min at the first ventilatory threshold |
| Microcycle | 4 days, repeated: day 1 SIT, day 2 HIIT, day 3 LIT, day 4 active rest |
| Cadence during SIT and HIIT | POLLC | POLFC |
|---|---|---|
| Repetitions | 50-70 rpm | freely chosen, above 80 rpm |
Tests before and after: incremental test for maximal aerobic power (Pmax), power at the second ventilatory threshold (VT2), VO2max, maximal pulmonary ventilation (VEmax) and gross efficiency (GE), plus a VO2max verification test.
Key Results
| Metric | Statistics (abstract) | Reading |
|---|---|---|
| Pmax | time effect F = 21.62, η² = 0.50, p = 0.00; time × group F = 4.99, η² = 0.18, p = 0.03; post-hoc Scheffé: increase significant only in POLLC | low cadence won |
| VO2max | time effect F = 39.39, η² = 0.64, p = 0.00; time × group F = 6.67, η² = 0.23, p = 0.02 | both improved, the groups differed in how much (direction not stated in the abstract; the title attributes the greater gain to low cadence) |
| VT2 power | Friedman: changed over time only in POLLC (χ² = 11, p = 0.001, W = 0.917) | low cadence won |
| VEmax | time effect F = 5.99, η² = 0.21, p = 0.02; no group interaction in the abstract, but the full-text Results report time × group F = 4.58, η² = 0.17, p = 0.04, VEmax rising only in POLLC (120.4 → 128.6 l/min, p = 0.032; POLFC 121.0 → 121.6, p = 0.997) (corrected 2026-10-12, full text) | low cadence won (corrected 2026-10-12, full text) |
| VT1 power | full text: time effect F = 19.23, η² = 0.47; rose in POLLC 129.0 → 157.1 W (p = 0.002), not in POLFC 128.4 → 138.5 W (p = 0.459) (corrected 2026-10-12, full text) | low cadence won |
| Gross efficiency | measured; result not reported in the abstract | — |
Authors' conclusion: the polarized program with SIT and HIIT at low cadence was more effective at improving aerobic capacity in well-trained female cyclists than the same program at freely chosen cadence — cadence, not only intensity and duration, is a variable to prescribe in interval training.
Why It Might Work (interpretation, not measured in this study)
Intensity was high: SIT maximal, HIIT 90-100% MAP. Not from this paper: in the negative low-cadence trial REF-118 the low-cadence intervals were at moderate intensity (73-82% HRmax) — the intensity, not the cadence, is the likely difference.
Cadence 50-70 rpm, not the 40 rpm of [REF-118] (not from this paper): a range in which power can still be held.
Inference, not tested: at 50-70 rpm and 90-100% MAP the torque per pedal stroke is higher, which is the usual argument for extra type II fibre recruitment during aerobic work; no biopsy or EMG was taken here, so the mechanism is presumed.
Practical Application
Limitations
Female cyclists only (male transferability likely but unconfirmed). 8 weeks (long-term effect unknown). No biopsy (type II recruitment mechanism presumed, not directly confirmed). Small groups (12 + 12); the abstract does not state randomisation. Percent changes and the gross-efficiency result are not in the abstract.