Warm-up science: static stretching versus dynamic prep

October 10, 2026 14 min read

Infographic, Warm-up science, static versus dynamic: dynamic strength and power improving roughly 4 to 6 percent per degree Celsius of muscle temperature, sprint cyclists keeping peak power 9.6 percent higher by preserving thigh warmth, 60-second static holds reducing later performance about 4.6 percent and maximal strength about 5.4 percent, dynamic stretching producing a small improvement, and an illustrative 20-40-60-80 percent approach-set progression

Straight to what to do

How to build the warm-up The one-page recap

TL;DR

As muscle temperature rises, contraction chemistry speeds up and blood flow increases: jumping, sprinting and dynamic strength improved by roughly 4-6 percent for each 1°C of muscle warmth under tested conditions, while static strength was considerably less temperature-sensitive.
In sprint cyclists, preserving muscle temperature after the warm-up increased peak power by 9.6 percent compared with letting the muscles cool.
Static stretching holds of 60 seconds or more reduced subsequent performance by approximately 4.6 percent, a broader meta-analysis found an average 5.4 percent maximal-strength reduction, and holds of 30-45 seconds generally produced little or no reduction.
Dynamic stretching, moving through a joint's range of motion, produced a small average improvement in performance.
A useful warm-up follows the demands of the activity: brief general movement, light rehearsal of the actual exercise, progressive loading toward working intensity, and stretching saved for after training or for genuine mobility restrictions.

Key facts

Roughly 4-6 percent improvement in dynamic strength and power per 1°C increase in muscle temperature.
Preserving thigh warmth after warm-up raised sprint-cycling peak power by 9.6 percent.
Static holds of 60+ seconds reduced subsequent performance by about 4.6 percent; maximal strength fell about 5.4 percent on average.
One 10-week experiment found 12.7 percent muscle growth without pre-workout stretching versus 7.4 percent with it, though an eight-week experiment found no significant difference.

Ever wondered whether your warm-up is actually helping your workout? Whether you're just starting to exercise or have been lifting for years, what you do before training can influence how much strength and power your muscles produce. And some familiar warm-up habits may even work against you.

What actually happens when you warm up?

Your muscles perform differently depending on their temperature.

As muscle temperature rises, the chemical reactions powering contraction become faster. Internal resistance decreases, muscle fibers can shorten more quickly, and blood flow increases.

Human experiments show how much this can influence performance:

Dynamic strength and power: Jumping, sprinting and dynamic strength performance improved by roughly 4-6% for each 1°C increase in muscle temperature under the tested conditions.
Static strength: Maximum force produced without moving was considerably less sensitive to temperature.
Maintaining warmth: In sprint cyclists, preserving muscle temperature after warming up increased peak power by 9.6% compared with allowing the muscles to cool.

Warmer muscles are particularly better prepared for producing force quickly. But warming up does not necessarily mean more repetitions or better fatigue resistance throughout an entire workout.

Muscle temperature also matters after the warm-up. Prolonged inactivity allows muscles to cool again, potentially reducing some of the performance benefits. This is particularly relevant when there is a long delay between warming up and demanding exercise.

There is also a difference between warming your body generally and preparing it for a specific exercise.

A few minutes of cycling can warm your legs, but do relatively little to prepare your chest and shoulders for pressing weights.

Lighter versions of the intended exercise combine local muscle warming with movement rehearsal, gradually preparing the muscles and nervous system for heavier work.

Why can stretching before training backfire?

Static stretching means holding a muscle in an elongated position, such as holding a hamstring stretch.

It can improve flexibility, but prolonged holds temporarily reduce muscle-tendon stiffness and can affect muscle activation and the speed at which force develops.

Several systematic reviews, meta-analyses and controlled human experiments reveal an important trade-off:

Long static holds: Stretching for 60 seconds or more per muscle group reduced subsequent performance by approximately 4.6%.
Maximal strength: A broader meta-analysis found an average reduction of 5.4% following static stretching.
Shorter holds: Approximately 30-45 seconds generally produced little or no meaningful performance reduction.
Dynamic stretching: Moving through a joint's range of motion produced a small average improvement in performance.
Long-term muscle growth: One 10-week experiment found 12.7% growth without pre-workout stretching versus 7.4% with stretching. Another eight-week experiment found no significant difference.

The immediate performance effects are relatively consistent, especially with longer static holds. Whether stretching before lifting meaningfully affects muscle growth over time remains less certain.

Improving flexibility and preparing to produce maximal force serve different purposes. Greater range of motion can be useful, but prolonged stretching immediately before demanding exercise may temporarily interfere with the force you are trying to produce.

What about injury prevention?

Stretching before a jog is a familiar ritual, often assumed to protect muscles and joints from injury. Yet a controlled trial in recreational runners found no reduction in running injuries from a combined warm-up, cool-down and stretching program. Stretching before steady-paced running has also shown no consistent improvement in running economy, while prolonged static holds may interfere with explosive sprint performance.

Structured warm-up programs combining strength, balance and coordinated movements have reduced injuries in football players. That benefit cannot be attributed to stretching alone.

Prolonged static stretching may also temporarily affect muscular joint stability. By reducing muscle-tendon stiffness and altering neuromuscular activation, it could influence how effectively muscles control joints under load. Human studies have reported changes in balance after stretching, although results remain mixed.

For strength training specifically, direct clinical evidence that warming up prevents muscle tears remains limited.

What does a good warm-up look like?

The most useful preparation generally follows the demands of the activity:

Start moving: A little comfortable movement helps transition from rest to exercise.
Prepare the actual exercise: Light, controlled versions of the intended movement warm the relevant muscles and rehearse coordination.
Build toward working intensity: Increase resistance for lifting or speed for sprinting, without accumulating unnecessary fatigue.
Stretch when useful: Brief targeted stretching can help with restricted mobility. Longer static holds generally fit better after training or separately.

A heavy lift may benefit from several progressive sets. For a relaxed jog, the first easy minutes may be the warm-up. Before sprinting, easy running, dynamic movements and gradual accelerations make more sense than prolonged static holds.

The goal is to prepare the muscles and movement you actually need, using only as much effort as necessary.

Warm up enough to perform well, without spending the energy you came to train with.

Practical details follow below, with a quick checklist at the end.

How to build the warm-up: the action plan

How to structure your warm-up sets

For resistance training, progressively heavier approach sets allow the relevant muscles to warm up while you rehearse the intended movement.

The principle is straightforward: start light, increase resistance gradually, and reduce repetitions as you approach your working weight.

For someone planning to squat with 100 kg, an illustrative progression might look like this:

20 kg (20%): 8-10 controlled repetitions
40 kg (40%): 5 repetitions
60 kg (60%): 3 repetitions
80 kg (80%): 1-2 repetitions
100 kg: Begin working sets

These percentages refer to your planned working weight, not your one-repetition maximum.

This is a practical example, not a scientifically established optimal protocol. The appropriate progression depends on the exercise, load and individual needs.

Not every exercise requires the same preparation:

First heavy compound exercise: Several progressively heavier sets may be useful.
Subsequent exercises using the same muscles: Fewer sets may be sufficient because those muscles are already warm.
Smaller isolation exercises: One lighter preparation set may be enough when the movement is familiar.
Beginners or lighter resistance training: Comfortable movement rehearsal followed by a gradual increase to the intended resistance may be sufficient.
Explosive exercises: Preserving muscle temperature and rehearsing rapid force production becomes particularly relevant.

More warm-up volume is not automatically better.

Light sets allow movement rehearsal with minimal fatigue. As resistance increases, lower repetition counts help familiarize you with heavier loads without accumulating unnecessary work.

The final preparation should leave you ready for your working sets, not already tired from approaching them.

Dynamic mobility and when to stretch

Dynamic mobility involves moving joints through a comfortable range of motion rather than holding a prolonged stretch.

The movements can be selected according to the exercise:

Before squats: Bodyweight squats, controlled leg swings or lunges
Before pressing: Arm circles, shoulder movements and light pressing
Before lower-body exercises: Controlled hip movements and leg swings
After prolonged sitting: A few minutes of walking or comfortable full-body movement

There is little reason to perform an elaborate mobility routine for every joint when only certain muscles and movements are needed.

Static stretching remains useful for improving flexibility, but timing and duration deserve attention.

For strength and explosive performance, the evidence suggests:

30-45 seconds per muscle group: Generally small or negligible acute performance reductions.
60 seconds or longer: Greater likelihood of measurable reductions in strength and power.
Longer flexibility sessions: Better placed after training or separately from demanding strength work.

These are approximate research-based distinctions, not absolute thresholds.

Stretching after training has not been established as inherently superior for improving flexibility. Its practical advantage is avoiding potential interference with the upcoming workout.

An important exception is restricted mobility.

If limited ankle mobility prevents someone from comfortably reaching an adequate squat position, a brief targeted stretch beforehand may help.

Following that stretch with controlled squats and progressively loaded practice sets allows the newly available range of motion to be incorporated into the exercise.

The aim is sufficient mobility for comfortable movement, rather than maximizing flexibility immediately before lifting.

Running and sprinting

For a comfortable jog, starting at an easy pace and gradually reaching the intended speed may provide most of the preparation needed. Routine static stretching is not required beforehand.

Sprinting demands faster force production. Easy running, controlled dynamic leg movements and progressively faster accelerations prepare the movement without starting at full speed. Prolonged static holds are a poor priority immediately before maximal sprints. These are practical progressions, not a validated universal distance or repetition protocol.

Maintaining muscle warmth

Muscle temperature can decline during prolonged inactivity after warming up.

This becomes relevant when substantial waiting time separates preparation from demanding exercise, particularly in colder environments.

Human research in sprint cyclists found that maintaining thigh temperature with electrically heated clothing during recovery increased subsequent peak power by 9.6% compared with the control condition.

Ordinary gym clothing has not been shown to reproduce that exact improvement, but the finding illustrates why preserving muscle warmth can matter for explosive performance.

In practice:

Long delays: Unnecessary waiting after completing the warm-up can allow muscles to cool.
Cold environments: Comfortable insulating layers can help reduce cooling during longer breaks.
Extended inactivity: A little light movement can help regain warmth before demanding exercise.
Normal rest periods: Adequate recovery remains useful. Constant movement is unnecessary.
Hot environments: Additional insulation may increase thermal strain and should be avoided.

Injury prevention and individual limitations

Movement preparation can support readiness and coordination, but it should not be treated as guaranteed protection against injury.

The strongest injury-prevention evidence in the supplied research comes from structured sports programs combining strengthening, balance and coordinated movement training.

For resistance training, appropriate loading, movement control and fatigue management remain important alongside warming up.

Existing injuries, painful movements or significant mobility restrictions may require individual modifications rather than simply additional stretching or preparation sets.

The one-page recap

General preparation: Brief comfortable movement after inactivity
Specific preparation: Warm the relevant muscles and rehearse the upcoming exercise
Progressive loading: Begin light and gradually approach working weight
Example progression: 20%, 40%, 60%, 80% of planned working weight
Example repetitions: 8-10, 5, 3, 1-2 respectively
Loading protocol: Illustrative progression, not a validated universal optimum
Heavy compound exercises: Several progressive preparation sets may be useful
Subsequent exercises: Less preparation when relevant muscles are already warm
Beginners and lighter exercises: Simpler preparation may be sufficient
Jogging: Begin easily and gradually reach the intended pace; static stretching is not required
Sprinting: Easy running, dynamic movement and progressive accelerations before maximal speed
Explosive movements: Prioritize muscle warmth and movement-specific preparation
Fatigue management: Reduce repetitions as resistance increases
Dynamic mobility: Controlled movements through the required joint ranges
Static stretching around 30-45 seconds: Generally small or negligible immediate performance impairment
Static stretching 60+ seconds: Greater likelihood of reduced maximal strength and power
Longer flexibility work: After training or in separate sessions
Restricted mobility: Brief targeted stretching followed by movement rehearsal when needed
Cold environments and long delays: Preserve muscle warmth without unnecessary activity
Rest periods: Maintain sufficient recovery for demanding sets
Hot environments: Avoid additional insulation and overheating
Injury prevention: Warm-ups do not guarantee protection against lifting injuries
Pain or existing injury: Individual exercise modifications may be necessary