I am cautious about plyometrics in a way that annoys some people, because the evidence for them is genuinely strong and I still make athletes wait.
The reason is that I have seen more Achilles problems come out of enthusiastic jump training than out of any other single thing I programme. Not because plyometrics are dangerous. Because they are the one stimulus where doing twice as much as prescribed does not give you twice the result, it gives you six weeks off.
This is the only part of a programme where doing more is not slightly worse. It is categorically worse.
Why They Are Worth the Care
Because they train the thing nothing else trains.
Running is a series of bounces. Each landing stretches the Achilles and the whole posterior chain, storing elastic energy, and a stiffer, more responsive tendon returns more of that energy for free. Free meaning it costs no oxygen. That is the definition of running economy.
Heavy strength work builds the muscle that produces force. Plyometrics build the spring that recycles it. They are different adaptations and you want both, and plyometric work is what alters the muscle-tendon behaviour that makes an athlete efficient.
The Rules I Do Not Bend
Fresh, never fatigued. This is the one that gets broken most. Plyometrics tacked onto the end of a session, on legs that have already done ninety minutes, is how tendons get hurt. Your landing mechanics degrade with fatigue, and bad landings under high load is the whole injury mechanism. If it goes in a session at all, it goes at the beginning.
Quality over quantity, always. Twenty good contacts beat sixty tired ones. The moment the landings get noisy or the ground contact time visibly lengthens, the set is over regardless of what the plan said.
Low volume, and lower than you think. Forty to sixty foot contacts in a session is plenty for an endurance athlete. Twice a week. That is not a warm up for a proper session, that is the session.
And on a day the readiness supports it. This is one of the clearest practical uses of a morning readiness score. Not to cancel training, but to decide whether today is a plyometric day or a steady day, because fast elastic work on a depleted nervous system is a bad trade every time.
The Progression
Four stages, and I do not let anybody skip.
First, pogo hops. Both feet, minimal knee bend, low, fast, off the ground as quickly as possible. The instruction is to be quiet. Noise means you are absorbing rather than bouncing. Two or three sets of ten to fifteen. Weeks one to three, and for some athletes weeks one to eight.
Second, skipping. Actual skipping, the thing children do. It is the most underrated conditioning tool in endurance sport, it loads the calf and Achilles in a running-specific pattern, and almost nobody does it because it looks silly. Two or three minutes.
Third, single leg hops. Now the load doubles, which is why it comes third and not first. Small, controlled, in place before travelling forward. Three sets of eight per side.
Fourth, and only for athletes with a solid base, bounding and short hill sprints of eight to ten seconds. The hill is deliberate: it loads the tendon hard while the incline keeps the impact forces lower than flat sprinting.
Depth jumps, box jumps from height, anything with a big drop, I simply do not use with endurance athletes. The risk is real and the additional benefit over the above is not.
Where and On What
Grass or a track, not concrete, and not a gym floor over concrete. Running shoes with some cushioning rather than lifting shoes.
And not in the same fortnight you make another change to your running load. If you have just increased cadence, or added hills, or gone up in weekly volume, that is not the fortnight to introduce jumping. Pick one variable.
Who Should Wait
Anyone with current Achilles, patellar or plantar pain. Anyone in the first eight weeks of a return from a bone stress injury. Anyone who cannot do fifteen good single leg calf raises through full range, because if the calf cannot control the load slowly it will not control it quickly.
That last one is my gate and it excludes more athletes than people expect.
The Bottom Line
Start with quiet pogo hops and skipping, twice a week, fresh, on grass, forty to sixty contacts, and stay there for longer than you want to.
Earn single leg work. Earn hill sprints. Skip depth jumps entirely. And put it on a day your body has something to give, because this is the one session where the difference between a good day and a bad one is the difference between an adaptation and an injury.
