Load the bar to 80% of your max. Grind out five reps. Hope your legs still fire for tomorrow’s ride.
That’s how most triathletes lift. A 2021 randomized trial on competitive female cyclists says it’s the slower way to get strong.
Why Triathletes Can’t Just Lift Like a Powerlifter
Percentage-of-max programming was built for people whose only job is to get strong. Load the bar to 85% of your one-rep max, your 1RM (the heaviest weight you can lift once), do your sets, go home and recover.
Triathletes don’t get that deal. You lift Tuesday, swim Wednesday morning, and hit a threshold ride Thursday. A fixed percentage doesn’t know any of that. It asks for the same effort whether you slept eight hours or four, whether yesterday’s brick left your legs fresh or fried.
Velocity-based training (VBT) solves a different problem. Instead of loading to a fixed percentage, you load to a target bar speed, measured in meters per second with a small sensor or a phone camera. If the bar moves slower than planned, you’re carrying more fatigue than the plan assumed, and the load adjusts.
In short: the bar speed tells you the truth about today, no matter what the spreadsheet says.
The 2021 RCT: Velocity-Based Training Beat Traditional Loading in Competitive Female Cyclists
The clearest sport-specific evidence comes from Montalvo-Perez and colleagues, published in Frontiers in Physiology in 2021. Seventeen competitive female cyclists split into two groups for six weeks of hip thrust, squat, and split squat training.
One group trained the traditional way: 80 to 90% of 1RM, four to eight reps a set. The other loaded by bar speed instead, working at roughly 65% of 1RM and stopping each set once the bar slowed down, about eight reps, give or take three.
The velocity group won on every strength and power measure that mattered.
Max power output climbed from 283 to 459 watts in the velocity group, compared with 278 to 363 watts for traditional loading. Both differences were statistically real (p=0.015).
Here’s the part that should change how you think about gym work: the velocity group got these numbers while lifting lighter. Sixty-five percent of max, not 80 to 90%. Less grinding, more strength.
Squat gains came out roughly equal between groups, around 30 to 35%, and both groups improved cycling time-trial power by 3 to 5%. Strength transferred to the bike either way.
Translation: you don’t have to grind near failure to get strong. You have to move the bar with intent, and stop the set before speed collapses.
The 2025 Meta-Analysis: 17 Studies, Same Verdict
One trial on 17 cyclists is a start, not proof. A 2025 systematic review and meta-analysis in BMC Sports Science, Medicine and Rehabilitation pooled 17 studies and 348 trained participants comparing velocity-based against percentage-based loading.
The pattern held. VBT produced small but real advantages in jump performance and change-of-direction ability, exactly the qualities that carry over into running and cycling force production. Maximal strength gains came out roughly even between methods. VBT athletes got there with less total training stress.
Think of it like two ways to fill a gas tank. One driver fills to a fixed number every time, whether the tank was half-empty or nearly full. The other checks the gauge and fills exactly what’s needed. Both cars run fine. Only one driver risks overflowing on a day they didn’t need it.
Why Lifting Heavy Helps You Swim, Bike, and Run At All
Before going further into loading method, it’s worth answering the obvious question: does strength training even help triathletes?
A 26-week study of 25 long-distance triathletes tracked what strength training actually changes. Moderate loads (8-12 reps, up to 75% of 1RM) improved cycling economy in the first 14 weeks. Heavier loads (1-6 reps, 85%+ of 1RM) then improved running economy over the next 12 weeks. Both changes were statistically significant. Body mass didn’t budge. The endurance-only comparison group showed no economy improvement at all.
Better economy means your body burns less oxygen and less glycogen to hold the same pace.
That’s the whole ballgame in a long triathlon.
How Hard to Push Each Set: Velocity Loss Thresholds
VBT adds a second dial beyond load: how much the bar is allowed to slow down within a set before you rack it, called velocity loss.
A 2022 dose-response meta-analysis of nine trials and 336 lifters found the sweet spot sits at 20 to 30% velocity loss, producing an average 1RM gain of 13.59 kilograms over the study period (95% CI 10.28-16.89). Push much further and returns stop scaling with the extra fatigue.
Training efficiency, how much strength you gain per rep performed, tells the same story from another angle. At 0% velocity loss, lifters gained 0.11 kilograms of strength per rep. Push to 50% velocity loss, grinding much closer to failure, and efficiency fell to 0.02 kilograms per rep, more than five times worse.
A separate 8-week squat study compared 0%, 10%, 20%, and 40% velocity-loss groups in 64 men. The 10% and 20% groups produced the biggest 1RM gains, not the group that pushed hardest.
Stopping short pays off.
For a triathlete, that’s the whole point. You can do real strength work, one to three reps short of failure by feel, and still have legs for a bike session later that day.
Load-Velocity Targets for the Squat and Hip Thrust
Research on the free-weight back squat and hexagonal bar deadlift pinpointed peak power output well below traditional strength-block loading. Peak power sits at 64.6% of 1RM for the squat and 59.6% for the deadlift. Bar speed at 1RM measured 0.30 meters per second in the squat. The relationship between load and speed was almost perfectly linear (R²=0.963).
| Training Goal | Approx. %1RM | Typical Reps | Best-Fit Phase |
|---|---|---|---|
| Max Strength | 85-100% | 1-4 | Base |
| Power (peak output) | ~60-65% | 5-8 | Build |
| Speed-Strength | 40-55%, explosive intent | 4-6 | Peak |
Percentages anchor to the peak-power research above; exact bar speed at each zone still varies by lifter.
That last point matters more than it looks. A 2020 study of trained female athletes found bar speed at a given percentage of 1RM varied 11 to 25% between individuals in the squat and bench press. A shared chart like the one above is a starting point, not a personal prescription.
Your own bar speed, tracked over weeks, is the number that actually applies to you.
When Strength Work Fights Your Engine (and When It Doesn’t)
Concurrent training, doing strength and endurance work in the same window, carries a real interference risk. A 2023 systematic review found small negative effects on lower-body strength gains in men, but not women. Untrained endurance athletes also lost VO2max ground under concurrent training, while trained athletes didn’t.
That’s good news if you’ve been training a while. It’s also why rigid, percentage-based strength blocks fit triathletes worse than they fit powerlifters. A percentage-based set doesn’t know you swam 4,000 meters this morning. A velocity-based set does, because the bar tells on you the moment it moves slower than it should.
Turning Bar Speed Into a Daily Readiness Signal
Coaches using VBT for autoregulation track bar speed against a rolling 30-day average for the same load. The system works like a traffic light. Above 95% of normal speed, train as planned. At 90-95%, cut volume or load. Below 90%, back off hard for the day.
That’s the same logic AthleteOS applies to strength scheduling. Instead of pinning your lift day to a fixed slot on the calendar, it looks at your fitness score (CTL) and HRV trend. Then it places the session where your body can actually absorb it. Log your sets with load, reps, and bar speed. It tracks your bar-speed-to-load ratio over time and flags a session where today’s speed falls outside your normal band, and over weeks it confirms whether the trend at a fixed load is genuinely rising.
Take a 70.3 athlete I’ll call Dana, 34, six years of consistent training, 9 hours a week across three sports. For two years she followed a generic strength plan: three sets of five back squats at 85% of a 1RM she tested twice a year. Some weeks it felt easy. After a hard bike weekend, the same weight felt like a max-effort lift, and her next two training days suffered for it.
She switched to loading by bar speed, targeting 0.5 m/s and stopping sets at 20% velocity loss. On fresh weeks, that meant lifting close to her old 85% number. On fatigued weeks, the same speed target only let her load to 68-70% of 1RM, and the set still counted as real training. Eight weeks later, her hip thrust had moved up 12 kilograms. Her training log showed none of the fatigue-driven overreach her old fixed-percentage plan had triggered three separate times that same block.
Keep building the aerobic side of that equation with the mitochondrial case for Zone 2 training. If bricks are part of your week, see how often 70.3 athletes should actually schedule them. If your bike and run thresholds don’t seem to agree with each other, this piece on critical speed versus FTP is the companion read. You can see how AthleteOS schedules strength sessions around your concurrent training load directly in the app.