Strength Endurance Test: Plank

The Plank Test, also known as the prone bridge test, assesses how long a client can maintain a standard plank position. It is best described as a trunk endurance and positional control test rather than a maximal core strength test.

Introduction

Trunk endurance can influence how well a client maintains body position during sport, exercise and daily tasks. The Plank Test is simple, low cost and easy to repeat.

Although often called a “core strength” test, the plank is more accurately described as a trunk endurance test because the primary score is hold duration.

Quick Summary

Test name: Plank Test
Alternative name: Prone bridge test
Category: Trunk endurance / core endurance
Primary score: Time held in seconds
Equipment: Stopwatch or Measurz stopwatch
Best suited to: General fitness, sport and progress monitoring
Key limitation: Norms vary because protocols and stopping criteria differ.

What Is This Assessment?

The Plank Test requires the client to hold a prone bridge position while maintaining alignment. The score is the total hold time.

A sport-specific endurance plank study examined the validity and reliability of a plank-based endurance protocol for evaluating global core muscle function in athletes.  

Why It Is Used

The Plank Test may be used to assess:

• Trunk endurance
• Positional control
• Anti-extension endurance
• Whole-body bracing capacity
• Baseline and retest change
• Progress after trunk endurance training

What It Measures

The primary score is:

Time held in seconds

The result may reflect:

• Trunk endurance
• Shoulder endurance
• Hip and gluteal contribution
• Body mass influence
• Pain or symptom response
• Motivation and familiarisation

It does not isolate the abdominal muscles or directly measure maximal trunk strength.

Who It Is Useful For

The Plank Test may be useful for:

• General fitness clients
• Field and court sport clients
• Runners
• Gym and strength-training clients
• Exercise professionals monitoring trunk endurance

It may not be appropriate for clients who cannot tolerate the prone position or who develop symptoms during testing.

Equipment Required

• Stopwatch or Measurz stopwatch
• Flat surface
• Optional mat
• Optional inclinometer to monitor trunk or pelvic position
• Optional Measurz AR measurement for setup documentation
• Optional Measurz metronome and rep counter for related dynamic trunk endurance tests
• Measurz platform for time, version, symptoms, compensations and retest comparison

Step-by-Step Protocol

Setup

1. The client lies face down.
2. Elbows are positioned under the shoulders.
3. Forearms are on the floor.
4. Feet position is standardised.
5. The client lifts into a straight-line plank.

Test Procedure

1. Start timing once the correct position is achieved.
2. The client holds as long as possible.
3. Stop timing when the client loses alignment, raises or drops the hips, shifts excessively, reports intolerable symptoms or chooses to stop.
4. Record time in seconds and reason for stopping.

Scoring and Interpretation

The primary score is:

Plank hold time in seconds

Interpretation should consider:

• Elbow position
• Foot position
• Hip height
• Spinal alignment
• Shoulder fatigue
• Body mass
• Pain or symptoms
• Stopping criteria

Normative Data, Benchmarks or Reference Values

Practical Adult Comparison Guide

Use these as broad practical benchmarks:

• Excellent: 180 seconds or more
• Good: 120–179 seconds
• Moderate: 60–119 seconds
• Developing: 30–59 seconds
• Low current endurance profile: under 30 seconds

These are not universal norms. Athletic groups may require higher expectations, while general clients may show meaningful progress at lower durations.

Reliability and Validity

A sport-specific plank endurance test has been studied for validity and reliability in young athletes. More recent research has examined criterion-related validity and reliability of the front plank test in adults, supporting the need for standardised protocols and population-specific interpretation.  

To improve reliability:

• Use the same plank version.
• Standardise elbow and foot position.
• Define hip-height failure clearly.
• Use the same encouragement style.
• Record symptoms.
• Avoid testing after fatiguing trunk or upper-body training.

Common Errors and Limitations

Common errors include:

• Hips rising too high
• Hips dropping into lumbar extension
• Shoulders drifting behind elbows
• Excessive shifting
• Holding breath
• Inconsistent stopping criteria
• Comparing different plank versions

Practical Applications

The Plank Test can help monitor trunk endurance, track progress, compare baseline and retest scores, and combine findings with side plank, push-up, shoulder endurance and lower-limb assessments.

How to Record This in Measurz / MAT

Record:

• Test name
• Version: forearm plank, high plank or modified plank
• Time held
• Foot position
• Elbow position
• Pain score
• Symptoms
• Reason for stopping
• Compensations
• Retest date
• Related trunk, shoulder or push-up tests

The Measurz stopwatch supports timing. The inclinometer can help standardise trunk or pelvic position, and the rep counter/metronome can support related dynamic core endurance tests.

Related Tests or Internal Links

• Push-Up Test
• Side Plank Test
• Biering-Sørensen Test
• Trunk Flexor Endurance Test
• Wall Sit Test
• Shoulder Isometric Endurance Tests

FAQs

What does the Plank Test measure?

It measures how long a client can maintain a plank position and provides information about trunk endurance and positional control.

Is it a core strength test?

It is better described as a trunk endurance test rather than a maximal strength test.

What is a good plank time?

Holding 120 seconds or more may suggest good trunk endurance for many adults, while 180 seconds or more may suggest excellent endurance. These are practical benchmarks.

Can shoulder fatigue affect the result?

Yes. Shoulder fatigue can limit plank performance before trunk endurance does.

Key Takeaways

• The Plank Test is a simple trunk endurance assessment.
• The score is time held in seconds.
• Protocol and stopping criteria must be standardised.
• Practical benchmarks can help, but baseline comparison is often stronger.
• Measurz can track time, version, symptoms and progress.

References

Tong, T. K., Wu, S., & Nie, J. (2014). Sport-specific endurance plank test for evaluation of global core muscle function. Physical Therapy in Sport, 15(1), 58–63. https://doi.org/10.1016/j.ptsp.2013.03.003   

Rodríguez-Perea, Á., Aragón-Aragón, P., Cuenca-García, M., Cruz-León, C., Torres-Banduc, M. A., Sánchez-Parente, S., & Castro-Piñero, J. (2025). Criterion-related validity and reliability of the front plank test in adults: The ADULT-FIT project. Applied Sciences, 15(5), 2722. https://doi.org/10.3390/app15052722