For years, the gym-vs-bike argument for cyclists has run on anecdotes. Some coaches swear by heavy squats. Others say every hour in the weight room is an hour stolen from the bike. Both sides pointed at small, contradictory studies and called it evidence.

That changed with a systematic review and meta-analysis published in the European Journal of Applied Physiology, the first of its kind to pool the existing research on heavy strength training in endurance cyclists into one analysis. Seventeen studies. 262 cyclists, 60 of them women. Mean VO2max of 61.25 ml/kg/min across participants—these are trained athletes, not gym newcomers. The researchers pooled everything and asked a simple question: does heavy strength training actually move the needle for endurance cyclists, and if so, where?

The answer isn’t “yes, obviously” or “no, it’s a waste of time.” It’s more specific than either, and more useful.

Quick Answer

Heavy strength training (1-3 sessions a week, 5-25 weeks) produced measurable improvements in cycling efficiency, anaerobic power, and time trial/time-to-exhaustion performance. It did not improve VO2max, peak VO2max, maximal minute steady state, or anaerobic capacity. Translation: it won’t grow your aerobic engine, but it makes the engine you have run more efficiently and gives you a bigger kick when the effort gets hard and short.

What the Study Actually Did

This wasn’t a new experiment. It was a pooling of 17 existing studies on strength training in endurance cyclists, combined using standard meta-analytic methods to get an effect size and significance level for each outcome. That matters. Individual studies on 12-20 cyclists rarely have the statistical power to detect a real effect. Pool 262 cyclists across 17 trials, and patterns that were invisible before start to show up.

The interventions varied—1 to 3 gym sessions a week, running anywhere from 5 to 25 weeks. Here’s the detail that stood out to me: the researchers checked whether sex, body mass, training experience, or how often riders lifted (once a week versus three) changed the outcome. None of it did. The effect showed up regardless. That’s a rare thing to find in exercise science, where “it depends on the individual” is usually the honest answer to everything.

What Does Heavy Strength Training Improve for Cyclists?

Three things moved with statistical significance:

1. Cycling efficiency (effect size 0.353, p=0.012) — how much power you produce per unit of oxygen consumed. A more efficient rider goes faster at the same metabolic cost.
2. Anaerobic power (effect size 0.560, p=0.024) — your capacity for short, hard efforts. Attacks, sprints, punchy climbs.
3. Cycling performance (effect size 0.463, p=0.016) — measured as time trial performance and time-to-exhaustion. This is the outcome that actually matters on race day, and it moved.

Anaerobic power showed the largest effect of the three. If you’ve ever gotten dropped on a short, steep ramp not because your legs were empty but because you had nothing left for the surge, that’s the exact gap this training targets.

What It Didn’t Touch

Equally important: heavy strength training showed no significant effect on VO2max, peak VO2max, maximal minute steady state, or anaerobic capacity.

This is the part that separates a careful reading of this study from a marketing pitch. Your aerobic ceiling—the size of your engine—doesn’t move because you started squatting. That’s still built by hours in the saddle, at the intensities that stress your cardiovascular system directly. Sweet spot, threshold, VO2max intervals. Nothing about that changes.

What strength training seems to do instead is make the engine you already have work better and hit harder at the margins. Efficiency and anaerobic power aren’t your aerobic ceiling. They’re what determines whether you’re riding at 85% of your potential or 95% of it, and whether you have anything left when the race stops being steady-state.

Why This Matters for Time-Crunched Riders

Most of us aren’t training 20 hours a week. If you’re fitting cycling around a job and a life, the question isn’t “should I do more of everything.” It’s “where does the next hour of training time produce the most return.”

This study gives a real answer for one specific trade: is an hour in the gym worth more than an hour on the bike, for a rider who already has a base?

For raw aerobic capacity, no. Ride the bike. But for efficiency, anaerobic power, and race-day performance, the data says a short weekly gym commitment pays off in ways that pedaling harder on the same rides won’t replicate. That’s not a small finding for someone squeezing training into 8 hours a week around everything else in life.

And the frequency finding is the practical gift here. The analysis found no moderating effect from session frequency—meaning 1 session a week performed comparably to 3 in the pooled data. You don’t need to restructure your week around four gym days to get the benefit measured in this analysis.

A Realistic Weekly Structure

Nothing here replaces the FTP-building work you’re already doing. This slots in alongside it.

Day	Ride	Strength
Monday	Rest	Gym session (heavy compound lifts)
Tuesday	Intervals	—
Wednesday	Zone 2	Optional short gym session
Thursday	Intervals	—
Friday	Rest or easy	—
Saturday	Long ride	—
Sunday	Recovery ride	—

The lifts that matter here: back squat, deadlift or Romanian deadlift, and a single-leg variant like the Bulgarian split squat. Heavy means heavy—working in the 3-6 rep range at 80-90% of your one-rep max, not high-rep circuit work with light dumbbells. That’s the load the studies in this meta-analysis actually tested. Curls and machine work aren’t what moved these numbers.

A sensible starting dose: 2 sets of 5 reps on your main lift, once or twice a week, in season. Progress load slowly. You’re not trying to compete in a powerlifting meet—you’re trying to add force output without burying your legs before your next ride.

The Timing Problem Nobody Talks About

Here’s the honest caveat, and it’s not one this meta-analysis was built to answer: how do you schedule a heavy leg day without wrecking your next two interval sessions?

Heavy squats create real muscle fatigue, and unlike a hard sweet spot ride, that soreness lingers into the next day for a lot of riders. Put your gym session the day before your hardest bike workout and you’ll show up flat. A safer pattern is heavy lifting on a true rest day or paired with an easy zone 2 spin, with at least 48 hours before your next high-intensity ride.

This is also where the study’s finding on frequency helps time-crunched riders specifically. If one session a week produces a comparable effect to three, you only need to solve this scheduling puzzle once a week, not three times.

Where This Fits With Prehab and General Conditioning

If you’re already doing off-bike work—say, the 15-minute prehab routine that keeps hip flexors and rhomboids in check—heavy strength training is a different tool with a different job. Prehab maintains mobility and prevents the overuse injuries that come from months in one position. Heavy strength training is progressive overload aimed at force production. You can run both. They don’t compete for the same recovery budget the way two hard interval sessions would.

What Should You Actually Do With This

• If you’re time-crunched and racing: Add one heavy session a week, on a rest day or paired with an easy ride. Expect gains in efficiency and top-end power, not a bigger aerobic engine.
• If your limiter is aerobic capacity: This isn’t your answer. More structured riding at the intensities that build VO2max still wins. Save the gym time for once you’ve got that dialed in.
• If you get dropped on punchy efforts and short climbs: This is the study to pay attention to. Anaerobic power showed the biggest effect size of the three significant outcomes, and that’s exactly the deficit that shows up as “I had the legs everywhere except the last 30 seconds.”
• If you’re already lifting light and doing high reps: The meta-analysis pooled studies using heavy loads. Circuit-style gym work with light weight isn’t the same intervention, and there’s no reason to assume it produces the same result.

A Word on the Evidence Quality

The researchers behind this meta-analysis were upfront about a limitation worth repeating here: the certainty of evidence across the pooled studies was rated low. That doesn’t mean the findings are wrong—it means the underlying studies varied enough in design and quality that the exact size of the effect should be read as a reasonable estimate, not a precise number. The direction of the findings (efficiency up, anaerobic power up, TT performance up, VO2max unchanged) is the part worth trusting. The exact magnitude is worth holding loosely.

You can read the full study text if you want to see the study-by-study breakdown yourself.

The Bottom Line

This is the first pooled analysis of its kind in endurance cyclists, and it answers a question that’s been argued on forums for a decade with actual numbers instead of gym-bro certainty or trainer-purist dismissal. Heavy strength training, done once to three times a week for as little as five weeks, improves cycling efficiency, anaerobic power, and time trial performance. It does nothing for your VO2max.

If you have an hour a week to spare and you’re already doing the aerobic work, that hour is well spent under a bar—not on the trainer doing more of what you’re already doing.

---

Analysis based on Llanos-Lagos et al., “Heavy strength training effects on physiological determinants of endurance cyclist performance: a systematic review with meta-analysis,” European Journal of Applied Physiology, 2025. Individual results vary based on training history and how the strength work is integrated with your riding schedule.