REF-238 · Brennan et al., 2019 · Medicine & Science in Sports & Exercise, Vol. · Paper · PubMed

The Effect of Cadence on the Mechanics and Energetics of Constant Power Cycling

Blimited evidenceMeasured on a mixed groupWritten before October 2026, being re-checked

Participants

Cyclists; sample size and training status are not given in the abstract (full text; not checked against the abstract).

Protocol

Constant submaximal power of 2.5 W/kg at 40, 60, 80 and 100 rpm, plus a preferred condition with cadence feedback hidden
Measured: metabolic cost, lower-limb kinematics, joint-level work, vastus lateralis (VL) fascicle mechanics (ultrasound), EMG of VL, rectus femoris, biceps femoris, gastrocnemius medialis and soleus

Key Results

Metabolic cost lowest at 60 rpm — but the mean preferred cadence was 81 rpm
Distribution of joint work did NOT change with cadence: constant across cadences, with most positive work done at the knee
Preferred cadence coincided with the highest VL power capacity (based on fascicle shortening velocity), without a significant penalty to efficiency
Conclusion: cyclists prefer a higher-than-economical cadence so that the muscle's ability to produce positive power stays high; the feedback mechanism behind this is still unknown

Mechanism

At constant power, a lower cadence means more force per pedal stroke and slower fascicle shortening; a higher cadence means less force but faster shortening. The preferred 81 rpm placed the VL where its power capacity was highest, and the joint-work split (knee-dominant) stayed the same at every cadence — cadence changed muscle operating conditions, not which joint did the work.

Practical Application

At a constant 2.5 W/kg, the metabolic optimum was 60 rpm but cyclists chose 81 rpm; the preferred cadence gave the highest vastus lateralis power capacity without a significant efficiency penalty, and the split of work between hip, knee and ankle did not change with cadence (knee did most). Self-selected cadence is not the most economical one — it buys power reserve at little metabolic cost.
ERG mode: fixing power does not fix the physiological stimulus — cadence sets pedal force, fascicle shortening velocity and metabolic cost even when the trainer reports identical watts. Inference, not tested: a "threshold" interval at 70 vs 95 rpm is a different muscular task at the same power.
Preferred-cadence rationale: a self-selected cadence around 80 rpm (81 in this study) keeps the muscle's power capacity high — relevant where surges are needed on variable terrain; grinding at the 60 rpm economy optimum trades that reserve for a small efficiency gain.
EMG optimum shifts with power: MacIntosh 2000 REF-237 (57 → 99 rpm from 100 to 400 W).

Limitations

Single submaximal intensity (2.5 W/kg); no high-intensity conditions; laboratory setting; sample size not reported in the abstract; fascicle mechanics measured in one muscle (VL).

How this entry was checked and changed
Why this level

regraded 2026-09-27 from B+: small within-subject measurement study, sample size and training status not stated in the abstract

Content correction 2026-09-27
"Joint mechanics change significantly with cadence: hip/knee/ankle work redistribution" and the Mechanism built on it -> the abstract says the distribution of joint work remained constant across cadences, with most positive work at the knee. Corrected in Key Results, Mechanism and lead.
"Higher cadence → higher metabolic cost but better power reserve" -> the abstract: preferred cadence had the highest VL power capacity WITHOUT a significant penalty to efficiency. "Trained cyclists", Tier 2-3 -> not stated in the abstract; Level B+ -> B.
"~80-90 rpm" -> the study's preferred cadence was 81 rpm. Cross-references REF-014 (duplicate of REF-084) -> REF-084; REF-083 (Ganio 2009, a caffeine meta-analysis) removed as unrelated.