The Strength You Cannot See: Isometric Training in Sprint Cycling

For a sport measured almost entirely in movement, it is an odd-looking way to train.

Yet the closer you get to the mechanical problem of sprint cycling, the less strange it becomes.

The opening pedal strokes of a standing start are built around enormous torque. The rider has time to force the gear around because the cadence is still low, and the first few revolutions are less about speed than overcoming inertia. A few seconds later the situation is completely different. The crank is travelling quickly, the time available to produce useful force has shortened dramatically, and the rider is trying to express as much of their physical capacity as possible before the pedal has already moved beyond the point where that force can be used.

That change in time is one of the defining problems of sprint cycling.

It is also why simply describing a sprinter as strong never tells the whole story.

A rider can possess an extraordinary amount of force-producing capacity and still be limited by how quickly that force appears, where in the pedal stroke it appears and how much of it ultimately reaches the crank. For younger or less developed riders, improving general strength can bring large gains. Once riders reach elite level, where enormous gym numbers are already normal, the problem becomes less straightforward.

At some point, getting stronger and getting faster stop being the same question.

When strength has to become cycling strength

That is where the work led by Mehdi Kordi becomes particularly interesting.

Kordi's research has repeatedly looked at what sits between gym strength and actual sprint performance. Rather than assuming that more general strength must automatically mean more cycling power, the work asks how that strength is expressed on the bike and whether the training stimulus can be made more specific to the task.

One of the most useful studies involved 24 elite track sprint cyclists over six weeks. Thirteen riders incorporated cycling-specific isometric strength work while the others continued with conventional resistance training.

The distinction matters because the intervention was not an attempt to remove normal strength training. The riders performing the isometric work still squatted afterwards, just at a more moderate load. What changed was the main maximum-strength stimulus.

Instead of relying entirely on a heavy compound exercise, the riders produced maximal three-second efforts against a fixed crank at several positions through the pedal stroke.

This was not a wall sit dressed up as cycling training. The riders were set up around their normal cycling position, the crank angles were selected from mechanically important parts of the stroke and torque could be monitored as they pushed.

The important point was not that the crank was stationary. It was what the stationary crank allowed.

On a moving bicycle the rider has only as long as the pedal gives them. Even during a maximal sprint, the crank continues to rotate and the opportunity to build force disappears with it. Fix the crank and that limit is temporarily removed. The rider can attack an effectively immovable resistance while remaining in a cycling position and producing levels of force which normal pedalling does not allow them to sustain.

For riders who were already producing around 1,540 watts at baseline, the result was notable.

After six weeks the experimental group had gained an average of 46 watts in absolute peak power. Relative peak power increased by 0.8 W/kg and cycling-specific maximum isometric torque rose by 12.5 per cent. Ten of the 13 riders improved relative peak power by more than two per cent.

It would be easy to stop there and turn the study into a simple argument for isometrics.

The more interesting part is that the riders who improved their maximum isometric cycling torque the most were not necessarily the riders who improved peak cycling power the most.

That is where the study starts to tell us something more useful about sprinting.

The force has to arrive in time

Separate testing looked at how quickly the riders could develop torque rather than simply how much they could eventually produce.

The relationships with peak cycling power appeared around 150 and 200 milliseconds.

They were not strong enough to explain the entire improvement and should not be presented as if they were. Nor did the intervention produce clear improvements at every force-time point. But the pattern is interesting because it reflects the problem riders actually face once the crank begins to accelerate.

Maximum strength gives the rider a ceiling. Sprint cycling then asks how much of that ceiling can be accessed while there is still time to use it.

At very low cadence, the rider can take longer to build torque. That is one of the reasons the first pedal strokes of a standing start can involve such enormous forces. The faster the rider goes, the less generous the crank becomes. Force has to appear sooner.

This is not an argument that maximum strength stops mattering. Without a large force reserve there is less available to express in the first place. It is about what happens once that reserve is already very large.

Elite sprinters can reach the point where another improvement in a general strength measure does not necessarily answer the problem they have on the bicycle. Their training has to find ways of taking existing physical capacity and making more of it useful.

Cycling-specific isometrics offer one way of doing that because they change the conditions under which force is produced.

The rider can work at positions which resemble the pedal stroke while removing the speed of the pedal itself. That creates a strange halfway point between the gym and the track. The movement is more specific than a conventional lift, yet the force demands can be greater than normal pedalling allows.

The choice of several crank positions in Kordi's study is important here. Isometric adaptations can be specific to the joint angles at which the athlete trains, so there would be little sense in treating one crank position as universally decisive. Using several positions broadens the stimulus and reflects the fact that the rider has to produce torque through a moving system rather than at a single point.

None of this makes conventional lifting less important.

A squat does not look like a pedal stroke, but it does not need to. Its value lies in developing physical qualities which can later be expressed elsewhere. The problem only arises if the gym number itself becomes the definition of progress.

The bicycle still has to see the benefit.

Somewhere between the gym and the track

Kordi's later work with Martin Evans and Glyn Howatson pushed the same idea in another direction.

Instead of preventing the crank from moving, quasi-isometric cycling allowed it to move very slowly against extremely high resistance.

The case study involved one highly trained sprint cyclist, so the results have to be treated accordingly, but the numbers were striking. Out-of-saddle peak power increased from 1,751 to 1,851 watts, while seated peak power rose from 1,671 to 1,728 watts.

The interest in that work is not really the temptation to copy the programme and expect another 100 watts.

It is the way the training begins to blur the traditional line between strength work and cycling.

A heavy gym exercise can produce huge forces but does so through a movement that is only indirectly related to pedalling. A maximal sprint is completely specific but is constrained by the speed of the crank. Isometric cycling fixes the crank and removes that speed. Quasi-isometric cycling lets it move again, but slowly enough that very high forces can still be produced.

They are different ways of manipulating the same underlying problem.

How much force can the rider create, how quickly can it be created, and how closely can the training stimulus resemble the task without losing the overload that made it useful in the first place?

That is a more interesting way of viewing sprint strength than simply separating training into "gym" and "bike".

It also explains why specificity should not be confused with automatic transfer.

A 2024 study examining isometric mid-thigh-pull strength and sprint-cycling torque found that stronger athletes generally produced greater cycling torque when riders were compared with each other. After training, however, the riders who improved their isometric strength the most were not necessarily those who improved their cycling torque the most.

That difference is easy to overlook.

A quality can be associated with good performance without every improvement in that quality causing an equivalent improvement in performance. Strong sprinters tend to be strong athletes, but making an already strong athlete stronger does not guarantee that the additional strength appears at the crank.

The same warning applies to cycling-specific tests. If a rider becomes very good at producing torque against a fixed crank, that is only useful if something eventually changes when the crank is allowed to move.

From research to the training week

For riders interested in using isometrics themselves, the Kordi study offers a useful framework, although copying an elite research protocol exactly would miss the wider point.

These were not long holds designed to create fatigue. The efforts lasted three seconds and were genuinely maximal, with substantial recovery between repetitions. Several crank positions were used and the volume was increased gradually across the six-week block.

The structure tells us more than the final session numbers.

This was maximum-strength work, not conditioning disguised as strength training. The quality of each effort mattered more than accumulating time under tension, and the riders were given enough recovery to keep producing very high torque.

The equipment and position matter as well. A maximal effort requires a properly secured setup capable of resisting it safely, while replicating the rider's normal cycling position as closely as practical helps preserve the reason for using a cycling-specific exercise in the first place.

More importantly, the intervention occupied space within an existing programme.

The experimental riders did not simply add a large volume of isometric work on top of everything they were already doing. Their main heavy strength stimulus changed, while moderate-load squatting, track work and other training remained.

That is probably the most useful lesson for anyone considering it.

Sprint cyclists rarely need more exercises simply because another exercise appears effective. The question is what the isometric work is intended to replace or modify, what physical quality it is trying to develop, and whether the benefit later appears in actual sprint performance.

Despite the lack of movement, maximal isometrics should not be regarded as cheap training. The external appearance may be static, but the force demands are not. They still need to sit sensibly alongside the track sessions where the rider actually needs to be fast.

What about before a race?

Isometric work can also appear much closer to competition, although for a very different reason.

Over six weeks, the aim is to change the athlete. During a warm-up, the aim is to influence what the athlete can express over the next few minutes.

Research by Lynne Munro and colleagues looked at this in six international-level sprint cyclists. After their normal warm-up, riders performed either a dynamic high-inertia conditioning protocol, four maximal five-second isometric contractions, or a control condition before subsequent sprint testing.

The results are useful precisely because they were not straightforward.

The clearest early standing-start improvement came from the dynamic condition after four minutes. The isometric condition became more interesting later, with changes at 16 minutes including improvements around the high-cadence side of the torque-cadence relationship.

That does not give us a universal pre-race formula, but it does illustrate the balance at work.

A maximal contraction can create fatigue at the same time as whatever potentiating effect is being sought. Test too soon and fatigue may dominate. Allow more recovery and the balance can change.

That makes the recovery interval part of the intervention rather than dead time between the warm-up and the race.

It also makes individual response important. One sprinter may respond well to a particular conditioning activity and recovery period while another simply feels heavy. This is why any use of maximal isometrics before competition needs to be established in training rather than discovered on the morning of an important event.

The purpose here is not to develop new strength. It is to create the conditions in which the rider might be able to express more of the strength they already possess.

The same type of muscular action can therefore serve two quite different purposes depending on where it appears in the programme.

The point is still to make the bike go faster

This is why isometric training is particularly interesting at the elite end of sprint cycling.

It is not because it has somehow superseded squats or because static contractions are inherently more sophisticated than conventional strength training. The riders in Kordi's own intervention continued to lift dynamically, and any serious sprint programme still has to combine general strength, specific power and actual sprinting.

Its value appears when the easy gains from simply becoming stronger have largely gone.

An elite sprinter can already possess extraordinary physical capacity. From there, progress increasingly depends on how that capacity is expressed: whether more force reaches the crank, whether it arrives quickly enough and whether it appears through positions which actually contribute to propulsion.

That is a much harder problem than adding weight to a bar.

Seen in that context, the apparently motionless rider pushing against a fixed crank no longer looks like they are training the opposite of sprinting.

They are isolating one part of it.

The bike has been prevented from accelerating so that the rider can spend a few seconds producing force without being chased by the pedal stroke. Over a training block, that can become a way of developing the rider's physical capacity. Used much more sparingly before competition, a similar contraction may instead help expose the capacity which is already there.

In either case, the final judgement belongs to the bicycle.

Not the size of the isometric number, not the angle at which it was produced and not how impressive the rider looked in the gym.

The crank has to turn, the bicycle has to accelerate and the rider has to go faster.

For sprint cyclists who are already exceptionally strong, learning how to make more of that strength arrive in the right place and at the right time may be where some of the remaining gains are hidden.

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