The physics of power: why the first 0.3 seconds matter most

Most sporting actions are over in under 0.3 s, yet maximal force takes 0.6–0.8 s to develop in a leg press and around 2.5 s in an isometric mid-thigh pull (Turner et al., 2020). So the athlete who wins is rarely the one with the biggest 1RM — it is the one who produces the most force in the time available.

Inside the shaded window, Athlete B produces more force despite a lower peak — which is why rate of force development matters so much in sport.

Four terms every coach should get right

Turner and colleagues (2020) make a useful distinction: “explode” is an excellent coaching cue, but in testing and reporting you should use the mechanical terms. They also recommend a simple, low-error metric for monitoring: force at fixed time points (e.g., 100–300 ms). If force at 200 ms goes up, impulse and RFD over that window must have gone up too.

The force–velocity trade-off

Force and velocity are inversely related: heavy loads move slowly, light loads move fast. Because sports span the whole curve — a rugby scrum sits at the high-force end, a baseball pitch at the high-velocity end — training should cover the full curve rather than one “optimal” load (Turner, 2009). Training effects are load-specific:

That is why a mixed-methods approach — strength and power trained together, with one emphasised per block — consistently outperforms either alone (Turner et al., 2021; Haff & Nimphius, 2012).

What actually makes a muscle strong

Strength is built from two toolkits — the muscle itself and the nervous system that drives it (Suchomel et al., 2018). Knowing which lever a method pulls tells you why it works.

The methods scorecard: what each tool is good for

No single method covers every adaptation — but bilateral lifting, eccentric work and variable resistance give the biggest strength return, while weightlifting derivatives and ballistic work lead for power (Suchomel et al., 2018). Ratings are the authors’ theoretical potential on a 1–5 scale.

Two findings stand out. Free-weight, multi-joint lifts transfer better than isolation machines: in one softball study, closed-chain training raised throwing velocity 3.4% versus 0.5% for open-chain work. And unilateral and bilateral programs produced similar strength and sprint gains in rugby players — but bilateral lifts allow heavier, safer loading, so unilaterals work best as assistance exercises.

Weightlifting derivatives and ballistic training: where power is made

Weightlifting derivatives produce some of the highest power outputs in the gym: about 52 W/kg in the second pull versus about 12 W/kg for the squat, bench and deadlift (Turner, 2009), with some derivatives reaching 80 W/kg (Turner et al., 2021). They have outperformed traditional lifting, jump training and kettlebell training for strength–power adaptations (Suchomel et al., 2018).

You don’t have to catch the bar

Pulling derivatives — mid-thigh pulls, pulls from the knee, jump shrugs, hang high pulls — drop the catch phase. Suchomel, Comfort and Lake (2017) list why that is useful:

• Equal or greater force, velocity and power in the second pull than catching variations.
• Similar or greater load-absorption stimulus on landing.
• Loads above the athlete’s 1RM clean (mid-thigh pulls have been studied up to 140% 1RM) for the high-force end of the curve.
• Lighter loads (≈30–45% 1RM hang power clean) for jump shrugs and high pulls at the high-velocity end.
• Lower technical demand, fewer mobility barriers and a neutral shoulder, elbow and wrist position.

The jump shrug sits at the high-velocity end and the mid-thigh pull at the high-force end; pairing them covers both extremes in one program.

Why “ballistic” beats “fast”

In a traditional bench press or squat, the bar must slow to zero at the top. Deceleration takes up about 24% of the movement with a heavy load and 52% with a light one (Turner, 2009). Kubo et al. found a braking phase at every load from 0 to 85% 1RM in the squat (cited in Turner et al., 2021). A ballistic exercise — jump squat, bench throw, med-ball throw, jump shrug — lets the athlete accelerate all the way, producing more force, velocity, power and muscle activation. Whatever the load, coach the intent to move explosively.

Eccentric training: the underused lever

Muscle produces roughly 20–60% more force when lengthening than when shortening, at a lower metabolic cost — so programs capped by concentric strength leave adaptation on the table (Suchomel et al., 2019). Heavy, fast eccentrics are linked to fast-twitch hypertrophy, longer fascicles, a possible shift towards type IIx fibres and a stiffer tendon.

The surprise for many coaches is tempo work. Most studies favour faster eccentrics for strength, power and RFD; slow lowering reduces the load you can use, the volume you complete and the eccentric peak force. Save it for specific hypertrophy or technique goals.

Plan for soreness. Eccentric work causes muscle damage and DOMS, which the repeated-bout effect blunts after early exposure. Allow 6–8 weeks between the end of an eccentric block and your target competition peak.

Move right only once landings are controlled; younger and weaker athletes stay longer in the early stages.

Dialling in the variables: load, sets, rest and velocity

The short version: train heavy (around 80–85% 1RM) for strength, stop well short of failure, rest 2–5 minutes, and let bar speed tell you when a set is done.

Why not grind to failure?

Fatigue sits in different places depending on how you train. When 13 men did 5 × 10RM versus 15 × 1RM, the hypertrophy protocol cut isometric force by about 48% versus about 30% for the maximal-strength protocol, with more lactate and a bigger drop in neuromuscular efficiency (Haff, 2012). More fatigue does not mean more strength.

Cluster sets protect quality

Breaking a set into mini-sets keeps bar speed high. In rugby players doing 4 × 6 jump squats at 40 kg, power and velocity fell in the later reps of traditional sets, while cluster sets attenuated the drop (Haff, 2012). Clusters suit hypertrophy and power work; evidence for pure strength gains is mixed.

Velocity-based training (VBT)

A linear position transducer turns every rep into feedback. A systematic review of elite athletes (Włodarczyk et al., 2021) found three useful ways to use it:

• Velocity-loss cut-offs: soccer players stopping sets at 15% loss improved CMJ more than a 30% group, despite doing less work.
• Velocity zones: working at a target speed (e.g., ≈1.0 m/s in the full squat) keeps intensity right on days when 1RM fluctuates. Periodised and fixed-zone plans worked equally well over 6–8 weeks.
• Instant feedback: rugby players who saw their peak velocity on every jump squat improved sprint and jump tests more than those who did not.

As the season nears competition, more of the work shifts up the line towards higher bar speeds.

Velocity bands vary between athletes, exercises and devices, so build an individual load–velocity profile. Use mean concentric velocity for squats and presses and peak velocity for weightlifting movements (Turner et al., 2021).

Putting it together: block periodization and phase potentiation

Periodized training beats non-periodized training for maximal strength, and sequenced blocks — where each phase sets up the next — appear to give the best strength–power results (Suchomel et al., 2018). Gains in muscle size and work capacity raise the ceiling for strength; strength then raises the ceiling for RFD and power.

A transition period of active recovery follows the competitive phase before the cycle restarts.

Individual-sport athletes (track and field, for example) suit single-targeted blocks: one quality emphasised, others retained with minimal “retaining loads.” Team-sport athletes often need multi-targeted blocks that develop compatible qualities together — strength–power, speed and change of direction — while keeping incompatible ones (like speed and high-volume aerobic work) apart.

An 18-week weightlifting-derivative progression

Suchomel, Comfort and Lake (2017) show how lift choice should move along the force–velocity curve as the season approaches. Loads are relative to the best weight achievable for that set-and-rep scheme, with day 3 lighter for recovery.

Kirby et al. (2010) make the same point with load: across three 4-week blocks, strength-training intensity climbs (70–80% → 80–90% → 85–95% 1RM) while volume falls, each block ends with a deload week, and the share of training given to speed grows until block 3 is dominated by near-bodyweight jump squats and on-field speed work. Strength is never dropped — Turner (2009) notes strength may be maintained for only about 2 weeks without it.

Weak or strong? Matching the emphasis to the athlete

Athletes squatting under about 1.6 × body mass should keep a strength emphasis; once they pass it, read their force–time profile to decide whether to push strength or ballistic work next (Turner et al., 2021).

As each athlete trains their weaker quality, the force–time curves reverse — so the emphasis swaps at the next block.

Weaker athletes. Almost any method makes an untrained athlete stronger, and a common error is rushing into high-velocity work (Suchomel et al., 2018). In relatively weak men (squat under 1.6 × BM), Cormie and colleagues found 10 weeks of strength training and 10 weeks of ballistic training improved jump and sprint performance about equally — the strength group through more neural drive and muscle thickness. A youth meta-analysis also favoured strength training before power training. Jumps and bounds stay in the program for coordination; they just are not the focus.

Stronger athletes. Strength still matters, but its returns diminish. Athletes squatting 2 × BM or more jump with more power, sprint faster and potentiate earlier and more than weaker peers, which makes plyometrics and complex training more productive (Suchomel et al., 2018). The long-term process becomes one of emphasis and de-emphasis: alternate strength-led and ballistic-led blocks, maintaining whichever quality is not the focus.

A field test for the profile: the explosive strength deficit

The explosive strength deficit (ESD) compares maximal force with the force reached in a fast movement (Turner, 2009). A large gap — around 50% or more — suggests ballistic training; a small gap suggests more strength (and size, if appropriate). Without force plates, compare squat-jump with countermovement-jump height, or 1RM power clean with vertical jump. Turner advises reading ESD with caution, as it rests largely on practical experience rather than primary research.

The coach’s checklist

• Test relative strength first — under ~1.6 × BM squat, prioritise strength.
• Build the base with bilateral, multi-joint free-weight lifts at ~80–85% 1RM.
• Stop sets short of failure; cap velocity loss at 10–20%.
• Rest 2–5 min between strength–power sets.
• Add ballistic lifts and pulling derivatives that accelerate all the way.
• Train across the whole force–velocity curve, not just at Pmax.
• Use heavy eccentrics and AEL; avoid slow tempo for strength–power goals.
• Sequence blocks: strength-endurance → max strength → strength–power → peak power.
• Keep a strength stimulus in every block, even near competition.
• Coach intent: every rep, every load, as fast as possible.