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Strength training for triathletes and endurance athletes

By the Tuffr team · Last updated · 10 min read

Yes, lift. Do two strength sessions a week in the off-season and keep one short session a week in the racing season. Use squats, hinges, single-leg work and pulls in heavy sets of 3 to 8 reps, with reps in reserve. Studies of endurance athletes link this to better economy.

Do triathletes and endurance athletes need strength training?

Mostly yes. A systematic review of 26 studies in well-trained endurance athletes found that adding strength training improved time-trial performance, economy, power at maximal oxygen uptake and endurance-specific muscle power. The evidence is not identical in every trial, so treat lifting as a well-supported addition, not a guarantee.

Two studies looked at triathletes. In 15 triathletes, two heavy lifting sessions a week for 14 weeks improved running economy beyond the endurance-only group. In 25 long-distance triathletes, 26 weeks of lifting improved cycling economy in the first half and running economy in the second, with no change in the endurance-only group.

Not every study agrees. In 19 well-trained female endurance athletes, heavy leg lifting twice a week for 11 weeks raised leg strength by about 40 percent but changed neither running economy nor a 40-minute all-out run. A survey of 390 long-distance triathletes found that 54.6 percent lifted. The most common barriers were lack of time (53.1 percent) and not knowing how to progress (52.5 percent).

Note

These trials ran for 11 to 26 weeks with small groups. They show what is likely to help, not what will happen to you. Judge lifting by how your training feels and how your key sessions go over a season.

Which lifts help runners, cyclists, swimmers and triathletes?

Squats or leg press, hip hinges, single-leg work and pulls cover most of what endurance athletes need. A review of runners and cyclists found that running economy improves with heavy or explosive lifting, while heavy lifting is the better choice for cycling economy. The table below is our recommendation.

Key lifts by sport (our recommendation)
SportWhat the lifts should doKey lifts
TriathlonCover all three sports with a small number of lifts, and keep the legs fresh for the long sessionsSquat or leg press, Romanian deadlift, split squat, row or pull-up, calf raise
RunningStiffer calves and tendons, strong hips, and single-leg controlSplit squats, step-ups, single-leg calf raises, Romanian deadlifts, light jumps
CyclingForce at low cadence and a strong trunk for long hours in the saddleSquats, leg press, deadlifts, hip thrusts, planks
SwimmingPull strength, shoulder health and a stable trunkPull-ups or lat pulldowns, rows, push-ups, band external rotations, planks

Key lifts by sport (our recommendation)

For swimmers the research is less clear. A systematic review of 27 studies in competitive swimmers found no consensus on which strength method works best, but swimming plus strength training seemed to beat swimming alone. If you also race fitness races, the strength training guide matches lifts to each station, and the fitness race and triathlon guide shows what the two sports share.

How often should an endurance athlete lift?

Lift twice a week in the off-season and base, once or twice in the build, and once in the racing season. These numbers are our recommendation. They sit below the ACSM figure of 2 to 3 days a week for novice lifters, because swimming, riding and running already use your recovery.

Lifting by phase for an endurance athlete (our recommendation)
PhaseSessions a weekSets and repsNotes
Off-season and base (8 to 12 weeks)23 sets of 8 to 12 reps, moving to 3 sets of 4 to 8Learn the lifts, then add load. Leave 2 reps in reserve.
Build1 to 23 sets of 4 to 6 repsHeaviest block. Keep a day between heavy leg work and a key bike or run.
Racing season12 sets of 3 to 5 repsMaintenance. Short, heavy and fresh, 20 to 30 minutes.
Taper and race week0 to 11 to 2 light sets of about 5 reps, or skipNo new lifts and no soreness before the start.

Lifting by phase for an endurance athlete (our recommendation)

  • A 26-week triathlete trial moved from 8 to 12 reps at up to 75 percent of one-rep max (weeks 0 to 12) to 1 to 6 reps at 85 percent or more (weeks 14 to 26). Our table follows the same direction, with fewer heavy sets.
  • In elite cyclists, lifting 1 to 2 days a week for 25 weeks (3 sets of 4 to 10 reps) improved strength and cycling power more than endurance training alone.
  • ACSM suggests raising the load by 2 to 10 percent once you can do one to two reps more than planned.

How do I keep my strength in the racing season?

Keep one short, heavy session a week. In a study of well-trained cyclists, one maintenance session a week for 13 weeks of the racing season preserved the muscle size and leg strength built before it, and their cycling power improved further. The study gives the frequency. The sets and reps below are our recommendation.

Stopping has a cost. In 7 elite cyclists who lifted for 25 weeks and then stopped, squat jump height, maximal aerobic power and 30-second sprint power fell within 8 weeks, compared with riders who had never lifted. Both studies were small, so read them as a pattern, not a rule.

  1. Keep the lifts you already know and drop the new ones.
  2. Do 2 or 3 lifts for 2 sets of 3 to 5 reps. Stop each set with 2 reps in reserve.
  3. Keep the load as heavy as in the build, and cut the number of sets, not the weight.
  4. Place the session on an easy day or after a short swim. Do not lift the day before a long ride or a long run.

What does a strength session for endurance athletes look like?

A good session has four or five lifts and takes 40 to 50 minutes in the off-season, then two or three lifts and 20 to 30 minutes in season. These are our sample sessions: tools for you to adjust, not a prescription. Learn each lift with a light load first.

Sample off-season session, about 45 minutes (our recommendation)
LiftSets and repsNotes
Back squat or leg press3 x 6 to 8Rest 2 to 3 minutes. Stop 2 reps short of failure.
Romanian deadlift3 x 6 to 8Hips back, flat back. Keep the bar close to the legs.
Split squat or step-up3 x 8 per legLower the weight for 2 seconds.
Row or pull-up3 x 6 to 10Swimmers: pull-ups or lat pulldowns first.
Single-leg calf raise3 x 10 to 15 per legStraight and bent knee on alternate weeks.

Sample off-season session, about 45 minutes (our recommendation)

Sample in-season maintenance session, about 25 minutes (our recommendation)
LiftSets and repsNotes
Squat or leg press2 x 3 to 5Same weight as the build phase. Stop 2 reps short.
Romanian deadlift or hip thrust2 x 3 to 5Smooth reps, no grinding.
Pull-up or row2 x 4 to 6Add 5 minutes of trunk work if you have time.

Sample in-season maintenance session, about 25 minutes (our recommendation)

How do I fit lifting around swim, bike and run sessions?

Put lifting on a day that already has a hard session, three hours or more after it, and keep the days before long sessions easy. Avoid heavy leg work the day before a long ride or long run. The week below is our recommendation for an 8 to 10 hour week and is easy to adapt.

Sample week with two lifting sessions (our recommendation)
DayEnduranceLifting
MondayRest, or an easy swimNone
TuesdayBike intervals, then an easy swimSession A, 3 hours or more after the bike
WednesdayEasy runNone
ThursdaySwim intervalsShort session B: pulls, trunk and single-leg work
FridayRest, or an easy spinNone
SaturdayLong ride, short run after itNone
SundayLong easy runNone

Sample week with two lifting sessions (our recommendation)

Order matters somewhat. A meta-analysis of 10 studies found that lifting before endurance work gave about 7 percent larger gains in lower-body dynamic strength than the reverse. A 2022 meta-analysis of 43 studies found that adding aerobic training did not change maximal strength or muscle size, but did reduce explosive strength, mostly in the same session. So when you double up, put the more important session first. See the weekly training structure guide for how the week fits together, and the brick workouts guide for the run after the ride.

Will lifting add bulk or slow me down?

Probably not at these volumes. In the 26-week triathlete trial the lifting group improved economy with no change in body mass. Our aim is force with low volume, not muscle size. The real cost is tiredness, so keep your key swim, bike and run sessions fresh.

  • Keep sets heavy and short, 3 to 6 reps (our recommendation), and leave 2 reps in reserve.
  • Keep most of your endurance training easy so that it does not eat into lifting recovery. The zone 2 running guide covers how easy that is, and the triathlon training hours guide covers how much time you have.
  • Do not add a lifting session in the week you add a long ride or run. Change one thing at a time.
  • Sore legs for more than two days after a session mean the load or the number of sets was too high.

Important

Stop a set if you feel sharp pain, dizziness or unusual breathlessness. If pain lasts, see a doctor or a physiotherapist before you carry on. If you are new to lifting, learn squats and deadlifts with a coach.

Can Tuffr track lifting next to swim, bike and run?

Tuffr is an iPhone app for athletes who train for fitness races and triathlon. It is not public yet: the closed beta is due by 30 November 2026, and a small group goes first. For lifting, we are building two things.

  • A gym log for sets, weights and rest, kept in the same plan as your swim, bike and run.
  • Coach AI, which proposes changes to your plan. You see what would change and why, and only what you approve reaches your calendar.

Note

A notebook works just as well for the tables above. Tuffr is a convenience, not a requirement. The hybrid athlete topic page has more guides: hybrid training guides.

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Frequently asked questions

Sources

Published figures are quoted from these pages. Where datasets disagree we say so. Advice marked as our recommendation is not from a source.

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