Recovery of power output and muscle metabolites following 30 s of maximal sprint cycling in man
Foundational PCr-resynthesis / repeated-sprint study
Protocol
n=14 male subjects performed two 30-s cycle-ergometer sprints separated by 1.5, 3 and 6 min of recovery, on three separate occasions
On a fourth occasion 8 of the subjects performed a single 30-s sprint and muscle biopsies were taken during recovery
Key Findings
At the end of the 30-s sprint, phosphocreatine (PCr) was 19.7 ± 1.2% and ATP 70.5 ± 6.5% of resting values; muscle lactate 119.0 ± 4.6 mmol/kg dry wt; muscle pH 6.72 ± 0.06
During recovery PCr rose rapidly to 65.0 ± 2.8% of rest after 1.5 min but reached only 85.5 ± 3.5% after 6 min; ATP and muscle pH stayed low (19.5 ± 0.9 mmol/kg dry wt and 6.79 ± 0.02)
Average half-time of PCr resynthesis (power-function model): 56.6 ± 7.3 s
Recovery of peak power output, peak pedal speed and mean power over the first 6 s of sprint 2 did not reach control values after 6 min and occurred in parallel with PCr resynthesis, despite the low muscle pH
High correlations (r = 0.71-0.86, P < 0.05) between the percentage PCr resynthesis and the percentage restoration of peak power, peak pedal speed and 6-s mean power after 1.5 and 3 min; no relationship between muscle pH recovery and power restoration (P > 0.05)
Authors' conclusion: PCr resynthesis after a 30-s maximal sprint is slower than previously seen after longer dynamic exercise, and PCr resynthesis is important for power recovery in repeated sprints
Practical Application
After a single 30-s all-out sprint in 14 men, muscle PCr was down to 19.7% of rest and had recovered only to 65.0% after 1.5 min and 85.5% after 6 min (half-time 56.6 s); sprint-2 peak power, pedal speed and 6-s mean power were still below control at 6 min and tracked PCr resynthesis (r = 0.71-0.86), not muscle pH — a 30-s maximal effort needs more than 6 min before the next one can be full, and the limiter is PCr, not acidosis.
The finding transfers as a timescale, not a formula: 1.5-3 min between all-out 30-s sprints leaves a large PCr deficit; even 6 min does not fully restore it.
Not from this paper; the base's own practice: the reasoning "higher aerobic capacity → faster PCr resynthesis → better repeatability" is why an aerobic base is trained even in sprinters; this study measured PCr kinetics but did not test aerobic capacity as a predictor — the repeatability construct is discussed in REF-477.
Limitations
n=14 (8 with biopsies); male subjects, training status not stated in the abstract
Single sprint duration (30 s) and three fixed recovery intervals (1.5, 3, 6 min); longer recovery untested
Aerobic capacity was not measured as a predictor of PCr resynthesis
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: within-subject lab study, n=14 (biopsies in 8)
Content correction 2026-09-27
"PCr recovers to ~85% within 90 s and ~95% within 3-5 min" -> 65.0% of rest after 1.5 min and only 85.5% after 6 min; half-time 56.6 s.
"Aerobic capacity ↑ → PCr resynthesis ↑ → repeatability ↑" -> not tested in this paper; relabelled as the base's own reasoning.
Added n=14 (8 biopsied), end-sprint PCr 19.7% / ATP 70.5% of rest, lactate 119.0 mmol/kg dw, pH 6.72, r = 0.71-0.86 with power restoration, no relation with pH. "Healthy untrained subjects mostly" -> deleted (training status not in the abstract). Level A -> B; Tier and Sport lines added.
2026-10-01: cross-reference repointed from a merged framework to the one that replaced it (SYNTH-01→31, 05→34, 09→70, 12/15→32, 19→26).