Plyometrics for Triathletes: Better Running Economy, Free
You have your bike FTP dialled in. Your run intervals are ticked off too. And your 3:10/km off the bike still will not come down. The problem is not the engine. It is the spring: how your muscles and tendons return energy with every stride.
That is where plyometrics comes in, a piece of training most age-groupers skip, and one that gives one of the best returns on effort in seconds anywhere in triathlon.
What the research says: 2.0 to 3.4% lower energy cost
The last decade of research is convincing. A randomised study by Eihara and colleagues (2024, European Journal of Sport Science) on recreational runners aged 30 to 50 found that plyometric training improved running economy at speeds typical for age-groupers (8 to 12 km/h) by 2.0 to 3.4% after ten weeks of regular training, twice a week.
Translated into triathlon terms: if you run a 1:40 half marathon off the bike at your IRONMAN 70.3, even a 2% improvement in economy is worth roughly two minutes, without adding training volume, without touching the engine, purely from better elasticity.
The mechanism? Plyometric training increases:
- Muscle-tendon stiffness. The Achilles tendon and plantar fascia get better at storing and releasing elastic energy
- Motor unit recruitment. More muscle fibres fire on each stride
- Neural firing rate. Signals to the muscles travel faster
- Ground contact time. The foot lands and pushes off 5 to 10% faster
That last point matters most for a triathlete. On the half marathon off the bike, “dead legs” react slowly. Plyometric training teaches the muscles to land and rebound almost automatically.
What plyometrics actually is
Plyometrics covers any movement that uses the stretch-shortening cycle (SSC). In plain terms: the muscle stretches (the eccentric phase), then immediately contracts (the concentric phase), and you use the elastic energy stored in the tendon for an explosive movement.
Examples, from easiest to hardest.
Level 0 (introduction):
- Pogo hops, small hops on the toes, 3×30 seconds
- A and B skips, familiar from a running warm-up
Level 1 (basic):
- Box jumps onto a 30 to 40 cm box, 3×8 reps
- Bounding, long, driven strides over 20 to 30 m
Level 2 (intermediate):
- Depth jumps off a 30 cm box, land and rebound immediately, 3×6
- Single-leg hops, 3×10 per side
Level 3 (advanced):
- Drop jumps from 60 cm with an immediate reaction
- Plyometric lunges, jumping lunges with a leg switch
The rule that matters most: ground contact needs to stay under 200 ms. If you land and sit in a half-second crouch before the next jump, that is not plyometrics, it is just jumping. The research does not promise any benefit from that.
A weekly plan for the base phase
Plyometric training does not replace run or strength training. It adds to it. Below is a realistic plan for a triathlete training 10 to 12 hours a week during the base phase (January to April).
| Day | Session | Plyometrics |
|---|---|---|
| Monday | Swim technique | None |
| Tuesday | Run tempo/intervals | 15 min after the run: pogo hops, box jumps, bounding, 2 sets each |
| Wednesday | Bike, zone 2 | None |
| Thursday | Gym (squat, deadlift) | After strength work: depth jumps 30 cm, 3×6, plus single-leg hops 3×10 per side |
| Friday | Swim, long set | None |
| Saturday | Long ride | None |
| Sunday | Long run | None |
Two sessions a week, 10 to 15 minutes each, is enough to trigger the adaptation. More does not produce a linear improvement, it produces injuries.
Five mistakes to avoid
Plyometric training looks simple, but it is punishing when done badly. The most common traps:
1. Jumping instead of plyometrics. A long ground contact time means no transfer to running. Focus on the speed of the rebound, not the height of the jump.
2. No progression. A week of pogo hops followed by 60 cm depth jumps is how Achilles tendinitis happens. Move up one level every three to four weeks.
3. Plyometrics the day before a long run. Muscles need 48 to 72 hours to recover from a hard plyometric session. Plan around it.
4. Skipping the warm-up. Ten minutes of easy jogging plus dynamic stretching before every session. No exceptions.
5. Ignoring pain. Pain in the Achilles, the knee or the shin means stop. Plyometric training is aggressive. If something hurts, back off rather than test it.
What about strength training?
The obvious question is plyometrics or squats. A meta-analysis by Eihara and colleagues (Sports Medicine Open, 2022) gives a clear answer: heavy strength training (squats at 85%+ of 1RM) improves running economy more than plyometrics alone. Combining the two works best of all.
The best combination for a triathlete:
- One gym session a week (squat, deadlift, pull-up, 4 to 6 rep ranges)
- Two plyometric sessions a week, 10 to 15 minutes each
The best results come from interventions longer than ten weeks, with 15 or more plyometric sessions total, at least twice a week. Starting in February gives you enough runway to build this into your race season.
This sits alongside IRONMAN 70.3 Bike Pacing: How Much FTP Can You Really Hold?. Racelify lists triathlons worldwide by date and distance.