Heavy lifting makes cyclists faster without touching VO2max

Endurance cycling performance rests on a handful of physiological pillars: maximal oxygen uptake (VO2max), the highest metabolic steady state the body can sustain, anaerobic capacity and power, and how efficiently a rider turns energy into forward motion. Strength training is widely used by cyclists, but the specific effect of genuinely heavy lifting, at or above 80% of one-repetition maximum, has never been cleanly separated from lighter gym work. Coaches and riders therefore disagree about whether heavy lifting helps endurance performance at all, and if it does, through which of these pillars the benefit arrives.

The authors systematically searched three major databases for studies indexed up to February 2025, looking for controlled trials in adult endurance cyclists where one group added heavy strength training for at least 3 weeks and a comparison group did endurance cycling training only. Seventeen studies qualified, covering 262 participants, 60 of them women, with an average starting VO2max of 61.25 ml/kg/min. The interventions ran from 5 to 25 weeks with 1 to 3 sessions per week. The team pooled outcomes for VO2max, power at VO2max, metabolic steady state, cycling efficiency, anaerobic capacity and power, and performance tests, then checked whether rider or programme characteristics changed the results.

Heavy strength training produced significant improvements in cycling performance, measured as time trials and time to exhaustion, alongside gains in cycling efficiency and anaerobic power. Strikingly, the classic endurance markers did not move: VO2max, power at VO2max, maximal metabolic steady state and anaerobic capacity all showed no significant change. No characteristic of the riders or the programmes, including sex, performance level, strength training experience, duration or session frequency, significantly altered the outcome. The authors rated the overall certainty of the evidence as low, which tempers how firmly any of this can be stated.

This supports a growing view that strength training helps endurance athletes not by enlarging the aerobic engine but by improving how economically and forcefully they use it. It clarifies earlier mixed findings by isolating genuinely heavy loading, and it confirms that performance gains can arrive with the oxygen-transport system essentially unchanged. Open questions remain about the best way to programme the lifting, since no dose pattern stood out in the analysis, and about whether the picture holds as larger and better-controlled trials are added to the evidence base.

For anyone who rides, this is a reason to think heavy gym work and endurance gains are not in conflict: the pooled trials suggest lifting made cyclists perform better without any cost to their aerobic numbers. It also reframes what to expect from a strength block, since the benefit showed up in efficiency and short, hard efforts rather than in VO2max. Because the evidence was rated low certainty, the size of the benefit for any individual rider remains uncertain, and the studies cannot yet say what the ideal mix of lifting and riding looks like.