Heavy Lifting for Bike Power: What Gym Strength Does (and Doesn't Do) for Your FTP

Most triathletes who lift do it for durability or injury resilience. TriForward's "Two Sessions a Week" covers the durability case, and "The Minimum Effective Dose" covers how little time it takes. This article asks a narrower question: does heavy gym work raise the power you can hold on the bike, the number most age-groupers track as FTP?

It's a fair question, because the idea sounds odd. A 40 km time trial or a 180 km Ironman bike leg uses a small fraction of your maximal leg strength on every pedal stroke. Why would getting better at lifting a heavy bar a few times help you push moderate force thousands of times?

The research gives a reasonably consistent answer: heavy lifting does improve cycling performance in trained cyclists, by a moderate amount, but not by making your aerobic engine bigger. It works through efficiency, muscle size and fibre changes, and short-burst power. The evidence comes almost entirely from cyclists, not triathletes, and its certainty is rated low.

What "heavy strength training" means here

The research covered here uses a specific definition. The 2025 meta-analysis discussed below defined heavy strength training as lower-body lifting at 80% or more of your one-repetition maximum, or sets of seven repetitions or fewer to failure. In practice that usually means squats, leg presses, deadlifts or lunges, in sets of around 4 to 10 repetitions with a weight that is genuinely hard to complete.

That's different from three common alternatives:

• Circuit-style or light, high-repetition work, such as 20 or more reps with light weights or bands. This feels like endurance training, and it's not what these trials tested.
• Explosive or plyometric training, such as jumps and bounds. TriForward's "Jumps or Iron?" covers this for running.
• On-bike "strength" work, such as big-gear, low-cadence intervals. That's the subject of TriForward's guide "Big Gear, Low Cadence".

FTP, threshold and what the studies actually measured

None of the studies below measured functional threshold power as most training platforms define it. They used laboratory and field measures that overlap with it:

• Mean power in a 40-minute all-out trial, used in several of the Norwegian trials.
• Power at a fixed blood lactate concentration, such as 2 or 4 mmol/L, a laboratory marker of threshold-type power.
• Time-trial or time-to-exhaustion performance, pooled together in the meta-analysis.
• Maximal metabolic steady state, the highest intensity where lactate and oxygen uptake stabilise.

Inference: a 40-minute all-out effort is close to how many riders estimate FTP, so improvements in that test are the nearest thing the research offers to an FTP change. That is a reasonable bridge, not a direct measurement. TriForward's "Is FTP 'Dead'?" covers why threshold measures differ.

The 2025 meta-analysis

The largest synthesis is a 2025 systematic review and meta-analysis by Llanos-Lagos, Ramírez-Campillo and Sáez de Villarreal in the European Journal of Applied Physiology. They searched for randomised and non-randomised controlled studies comparing endurance training plus heavy strength training with endurance training alone in endurance cyclists.

• Studies: 17, with 262 participants, of whom 60 were women.
• Interventions: between 5 and 25 weeks, with 1 to 3 sessions per week.
• Certainty of evidence: rated low using the GRADE system.

Compared with endurance training alone, heavy strength training led to:

• Better cycling performance (time trial or time to exhaustion): effect size 0.463.
• Better cycling efficiency: effect size 0.353.
• Higher anaerobic power, meaning short maximal efforts such as the Wingate sprint test: effect size 0.560.

It did not significantly change:

• VO2max or the power at VO2max.
• Maximal metabolic steady state.
• Anaerobic capacity.

The authors found no significant moderating effect of sex, body size, performance level or previous strength-training experience, or of programme length, frequency or total number of sessions. They concluded heavy strength training may improve endurance cycling performance, mainly through better efficiency and anaerobic power, but that the low certainty of the evidence prevents firm recommendations on how best to do it.

An effect size around 0.46 is usually described as small to moderate. Inference: it is a real but modest benefit, the kind of change that matters over a season rather than one you'd notice after a few weeks.

The 12-week trial in well-trained cyclists

Much of the evidence comes from one research group in Norway, led by Bent Rønnestad. A 2010 trial in the European Journal of Applied Physiology is typical:

• Participants: 20 well-trained cyclists. The strength group had 11 men; the endurance-only group had 9 cyclists, 7 men and 2 women.
• Programme: four lower-body exercises, 3 sets of 4 to 10 repetition maximum, twice a week for 12 weeks, alongside normal endurance training.

The results:

• The strength group increased thigh muscle size, maximal isometric force and Wingate peak power more than the endurance-only group.
• Power at 2 mmol/L blood lactate and mean power in the 40-minute all-out trial improved in the strength group.
• In the endurance-only group, 40-minute performance only tended to improve (p = 0.057).
• VO2max rose by a similar amount in both groups.

The authors noted the gain in thigh muscle size came without an increase in body mass, which speaks to a common worry that lifting will make a cyclist heavier.

Female cyclists

Women are underrepresented in this research, but not absent. A 2016 trial by Vikmoen and colleagues in the Scandinavian Journal of Medicine & Science in Sports studied 19 well-trained female cyclists for 11 weeks: 11 added heavy strength training to endurance training, and 8 continued endurance training only.

• The strength group improved one-legged leg press maximum and quadriceps size more than the endurance group.
• The strength group improved 40-minute all-out mean power, the fraction of VO2max they could sustain, and cycling economy. The endurance-only group didn't change on these measures.
• Muscle fibres shifted from the IIAX-IIX type towards the more fatigue-resistant IIA type.
• Individual improvements in the 40-minute trial correlated with gains in quadriceps size (r = 0.73) and with the fibre-type shift (r = −0.63).

A 2021 review by Vikmoen and Rønnestad in the Journal of Functional Morphology and Kinesiology compared the evidence by sex. They concluded that men and women appear to gain similar cycling benefits from adding strength training, that some data hint women may gain more in cycling economy, and that bigger leg muscles seem to be an important part of the benefit for women too. They noted most of the underlying research is in men.

The 2025 meta-analysis, with 60 women among 262 participants, also found no significant difference by sex.

Elite cyclists over 25 weeks

A common objection is that strength work helps only less-trained riders. A 2015 trial by Rønnestad and colleagues, also in the Scandinavian Journal of Medicine & Science in Sports, followed 16 young elite cyclists over 25 weeks: 9 added heavy strength training and 7 did endurance training only.

• The strength group improved half-squat strength, Wingate peak power, power at 4 mmol/L lactate and 40-minute all-out mean power.
• The gains in power at 4 mmol/L and in 40-minute power were larger than in the endurance group.
• Peak pedal force occurred earlier in the pedal stroke in the strength group, and that change correlated with the 40-minute improvement (r = 0.66).
• Neither group changed VO2max or cycling economy.

That last point matters. In this elite group, the benefit didn't come through the economy route seen in the female cyclists, which shows the mechanism isn't settled.

Why it might work

A 2014 review by Rønnestad and Mujika in the Scandinavian Journal of Medicine & Science in Sports concluded that the most convincing evidence for adding strength training to cycling comes from heavy strength training. They proposed several mechanisms:

• Delaying the use of less efficient type II fibres. If each fibre is stronger, each pedal stroke uses a smaller fraction of maximal force, so fewer of the less efficient fibres may need to be recruited, especially late in a long effort.
• Better neuromuscular efficiency, meaning the nervous system activates the muscle more effectively.
• A shift from IIX fibres towards more fatigue-resistant IIA fibres, as seen in the female cyclist trial.
• Stiffer muscle-tendon units, which mainly matters for running.

Inference: if these mechanisms are right, they fit the pattern in the meta-analysis. Heavy lifting changes how efficiently and powerfully you use the engine you have, not the size of the engine.

What it doesn't do

Being clear about what heavy lifting doesn't do is as useful as knowing what it does:

• It doesn't raise VO2max. No significant effect in the 2025 meta-analysis, and no difference between groups in the trials above.
• It doesn't replace threshold or interval training. In every trial, lifting was added to normal endurance training. Nobody tested swapping bike sessions for gym sessions.
• It doesn't work fast. Interventions lasted 5 to 25 weeks, and most of the clear results came from programmes of 11 weeks or more.
• It doesn't have a proven optimal dose. The meta-analysis found no clear effect of programme length or frequency, partly because the studies were small.

How this transfers to triathletes

Every study above was in cyclists. That leaves gaps for a triathlete:

• Nobody ran afterwards. The trials don't tell you whether better bike efficiency carries over into the run.
• Most participants were well-trained or elite cyclists. Many age-group triathletes are less trained on the bike, which might mean larger gains, but that hasn't been tested.
• Training time was mostly cycling. A triathlete splitting time across three sports may have less room to absorb heavy leg sessions.
• Masters athletes were rare. One study in the meta-analysis tested a sprint in masters cyclists, but most participants were younger.

Inference: the direction of the evidence is consistent, so heavy lifting is a reasonable bet for triathletes wanting more bike power. The size of the benefit for a 45-year-old age-grouper training 10 hours a week across three sports is unknown.

Putting it into practice

These suggestions are drawn from the trials above. They're not a tested triathlon programme:

1. Use heavy, multi-joint leg exercises. Squats, leg press, deadlift variations and lunges were common in the trials. Build towards sets of around 4 to 10 repetitions with a weight close to the limit for that number.
2. Lift twice a week in a building phase. The 12-week, 11-week and 25-week trials all used twice-weekly sessions while building. TriForward's guide "The Off-Season Strength Block" covers how to build and then maintain.
3. Give it time. Plan for at least 10 to 12 weeks before judging whether it has helped.
4. Keep your bike training. The gains in the trials were on top of normal endurance training, not instead of it.
5. Progress gradually. Start with lighter loads and fewer sets, especially if you've never lifted. Muscle soreness from the first weeks can disrupt your bike training more than the lifting itself.
6. Separate it from key sessions where you can. TriForward's guide "Lifting and Endurance in the Same Week" covers session order and spacing.

A triathlon scenario

The following example is illustrative, not drawn from a study. A 41-year-old man training for a 70.3 has an FTP of 240 W and trains about nine hours a week. His bike split is his weakest leg. He has never lifted.

Based on the evidence above, he might:

• Add two short gym sessions a week from November to February, focusing on squats or leg press and a hip-hinge exercise, starting light for the first few weeks.
• Keep his two key bike sessions, placing lifting after an easy swim or on an easy day rather than the day before a hard bike workout.
• Retest his FTP after about 12 weeks, knowing that any change also reflects his bike training, and that the trials suggest a modest effect, not a dramatic one.
• Move to a lighter maintenance phase in spring, rather than stopping completely.

Common mistakes

• Lifting light weights for high repetitions and calling it strength training for cycling. The trials used heavy loads.
• Expecting a VO2max boost. That isn't where the benefit appears.
• Starting heavy in week one. Severe soreness from a sudden jump in load can cost a week of bike training.
• Dropping bike intensity to make room for the gym. Lifting was added to endurance training in the trials, not swapped for it.
• Judging it after four weeks. Most of the positive trials ran for 11 weeks or longer.
• Stopping completely once the season starts. Gains fade if you stop, which is why the Norwegian trials used maintenance sessions in season.

What we don't know

• Whether heavy lifting raises FTP as measured in the field, since no trial used that test.
• Whether the bike gains carry into the run in a triathlon.
• How much less-trained, older or female age-groupers gain, given how few such athletes were studied.
• The best dose. The meta-analysis couldn't identify one, and its authors rated the overall certainty low.
• How it compares with simply riding more for the same extra time, which no trial has tested head to head.

References

• Llanos-Lagos C, Ramírez-Campillo R, Sáez de Villarreal E. Heavy strength training effects on physiological determinants of endurance cyclist performance: a systematic review with meta-analysis. European Journal of Applied Physiology, 2026;126(1):193–222 (online 2025). doi:10.1007/s00421-025-05883-2
• Rønnestad BR, Hansen EA, Raastad T. Effect of heavy strength training on thigh muscle cross-sectional area, performance determinants, and performance in well-trained cyclists. European Journal of Applied Physiology, 2010;108(5):965–975. doi:10.1007/s00421-009-1307-z
• Vikmoen O, Ellefsen S, Trøen Ø, Hollan I, Hanestadhaugen M, Raastad T, Rønnestad BR. Strength training improves cycling performance, fractional utilization of VO2max and cycling economy in female cyclists. Scandinavian Journal of Medicine & Science in Sports, 2016;26(4):384–396. doi:10.1111/sms.12468
• Rønnestad BR, Hansen J, Hollan I, Ellefsen S. Strength training improves performance and pedaling characteristics in elite cyclists. Scandinavian Journal of Medicine & Science in Sports, 2015;25(1):e89–e98. doi:10.1111/sms.12257
• Rønnestad BR, Mujika I. Optimizing strength training for running and cycling endurance performance: a review. Scandinavian Journal of Medicine & Science in Sports, 2014;24(4):603–612. doi:10.1111/sms.12104
• Vikmoen O, Rønnestad BR. A comparison of the effect of strength training on cycling performance between men and women. Journal of Functional Morphology and Kinesiology, 2021;6(1):29. doi:10.3390/jfmk6010029