Repetition Maximum Testing: Leg Press – Single Leg Test

A field sport athlete may show a clear difference in lower-limb strength between sides. A gym client may need a controlled machine-based option for unilateral strength tracking. A lower-limb training programme may use the single-leg leg press to monitor progress without requiring a squat or deadlift pattern.

The Leg Press – Single Leg Repetition Maximum Test provides a controlled way to assess unilateral lower-limb pushing strength using a standardised leg press machine setup. Rather than requiring a true 1RM attempt, the test can be performed using a submaximal repetition maximum, such as a 3RM, 5RM, 8RM or 10RM. The load and reps are then entered into Measurz to calculate the estimated 1RM.

The result is useful for strength tracking, but it should not be interpreted as a complete measure of squat strength, running performance, jumping ability, lower-limb function, injury risk or return-to-sport readiness.

What Is the Leg Press – Single Leg Repetition Maximum Test?

The Leg Press – Single Leg Repetition Maximum Test measures the heaviest load a client can press for a defined number of repetitions using one leg on a leg press machine.

Depending on the protocol, this may be a 3RM, 5RM, 8RM, 10RM or another repetition maximum. The repetition target should be clearly recorded.

The test may be performed using:

45-degree single-leg leg press
Horizontal single-leg leg press
Selectorised single-leg leg press
Plate-loaded single-leg leg press
Other standardised leg press setup

In Measurz, the professional records the load, completed repetitions and side tested. Measurz then calculates the estimated 1RM from that result. This estimated 1RM can be used to monitor progress over time, compare sides and guide loading decisions.

If the client performs a true single-repetition maximum, the result should be labelled as a directly measured 1RM. If the result is calculated from a submaximal load and repetitions, it should be labelled as an estimated 1RM.

Why It Is Used

This test is used to assess unilateral lower-limb pushing strength, compare sides and track strength changes over time.

It may be useful for athletes, gym clients, lower-limb strength clients and programmes where machine-based single-leg strength is a meaningful monitoring variable.

It is especially useful when the professional wants a strength estimate without requiring a true maximal 1RM attempt. A submaximal RM test can be more practical for many clients while still giving a useful estimated 1RM through Measurz.

What It Measures

The test measures single-leg leg press performance under the selected machine setup.

It may reflect:

Machine-based lower-limb pushing strength
Quadriceps, glute and lower-limb contribution
Side-to-side strength difference
Load tolerance
Control through the selected ROM
Pain or symptom response
Estimated 1RM progress across training blocks
Training load progression

It does not measure squat strength, isolated quadriceps strength, isolated glute strength, balance, sprint performance, jump performance, lower-limb injury risk or sport readiness on its own.

Who It Is Useful For

This test may be useful for field sport athletes, gym clients, runners, jumping athletes, lower-limb strength clients and anyone completing unilateral lower-limb training.

It may not be appropriate when the machine setup causes unacceptable pain, the client cannot control the tested limb safely, the test cannot be performed through a repeatable ROM, symptoms increase during loaded leg pressing, or the client is not ready for maximal or near-maximal repetition testing.

Equipment Required

Leg press machine
Load stack or plates
Safety stops
Measurz for recording load, reps, side and estimated 1RM
Optional metronome
Optional video
Optional seat-setting or foot-position marker

Step-by-Step Protocol

1. Choose the leg press setup

Decide whether the test will use a 45-degree, horizontal, selectorised, plate-loaded or other clearly defined leg press setup.

2. Record the setup

Record machine type, seat angle, backrest position, footplate position, foot placement, side tested, ROM, tempo, safety-stop position and load method.

3. Choose the repetition target

Select the repetition maximum target, such as 3RM, 5RM, 8RM or 10RM. Use the same target for retesting where possible.

4. Define valid ROM

Set a clear start and finish range. A valid repetition should include a consistent lower position, controlled press, no major pelvic lift, no knee collapse and no shortened ROM.

5. Warm up

Complete light warm-up sets on each side. Increase load gradually before testing.

6. Test one side at a time

Choose the testing order and keep it consistent. Allow adequate rest between attempts and sides.

7. Perform the test

Ask the client to complete the selected repetition maximum with controlled movement and the defined ROM.

8. Stop the attempt

Stop when the client reaches the target reps, cannot complete another valid rep, loses ROM, uses unacceptable compensation, reports limiting symptoms or cannot maintain control.

9. Record the maximum successful set

The score is the heaviest load completed for the target repetition range with acceptable technique and ROM.

10. Enter load and reps into Measurz

Record the completed load, repetitions and side tested in Measurz. Measurz calculates the estimated 1RM from the entered result.

Scoring and Interpretation

Record the load, reps, side tested and exact leg press setup. Measurz uses the completed load and reps to calculate the estimated 1RM.

The estimated 1RM should be interpreted as an estimate, not the same as a directly tested 1RM. If a true 1RM was performed, label it as directly measured. If the result comes from a submaximal load and repetitions, label it as estimated.

Interpretation should include:

Absolute load
Completed repetitions
Estimated 1RM
Side-to-side comparison
ROM
Machine setup
Foot position
Tempo
RPE
Pain or symptoms
Compensations
Previous baseline

A lower estimated 1RM on one side may suggest reduced single-leg leg press performance under the tested setup, but it does not identify the cause. Pain, fatigue, machine setup, ROM, foot position, confidence, recent training and technique may all influence the result.

Normative Data, Benchmarks or Reference Values

No universal normative value should be applied across single-leg leg press machines and populations. Results vary by machine design, seat angle, backrest position, footplate angle, foot position, ROM, tempo, training history and whether the 1RM is directly measured or estimated.

Use baseline comparison, side-to-side comparison and progress across sessions as the primary benchmarks.

A noticeable side-to-side difference should be interpreted alongside symptoms, movement quality, training history, lower-limb function and related strength findings. It should not be used as a strict pass/fail rule.

Because leg press machines vary substantially, results from different machines should not be treated as interchangeable.

Common Errors and Testing Limitations

Common errors include changing seat settings, changing foot placement, using inconsistent ROM, lifting the pelvis, allowing knee collapse, locking the knee aggressively, using momentum, changing tempo, testing while fatigued, not recording symptoms and comparing results across different leg press machines.

A common recording error is failing to distinguish between a directly measured 1RM and an estimated 1RM. When load and reps are entered into Measurz, the result should be described as an estimated 1RM unless a true 1RM was directly tested.

The main limitation is that the test measures machine-based single-leg pressing strength only. It does not fully assess squat strength, balance, gait, running performance, jumping ability, lower-limb injury risk or sport readiness.

Practical Applications

Use this test to monitor unilateral lower-limb pushing strength, compare sides, guide training loads and track response to lower-limb strengthening programmes.

The estimated 1RM can help track progress across training blocks, adjust loading and compare left-right differences when the same setup is repeated.

It is most useful when interpreted alongside squat, split squat, leg extension, leg curl, hop testing, sprint exposure, lower-limb symptoms and movement quality.

How to Record This in Measurz

Record protocol type, machine type, seat angle, backrest position, footplate position, foot placement, side tested, ROM, tempo, safety-stop position, load, reps, RM target, estimated 1RM, RPE, pain score, symptom location, compensation notes, reason for stopping and retest date.

Useful notes include shortened ROM, pelvic lift, knee valgus, foot slip, pain-limited stop, tempo failure, fatigue-limited attempt, side-to-side difference or machine setup change.

The key Measurz workflow is:

Enter the completed load
Enter the completed reps
Enter the side tested
Review the estimated 1RM calculated by Measurz
Record machine setup, ROM, symptoms, RPE and compensations
Use the same protocol for retesting

FAQs

What does the Leg Press – Single Leg Repetition Maximum Test measure?

It measures machine-based single-leg pressing strength under the selected leg press setup.

How does Measurz calculate the result?

The professional enters the completed load and reps into Measurz. Measurz uses this information to calculate the estimated 1RM.

Is the Measurz result a true 1RM?

Not unless the client completed a true 1RM. If the result is based on load and multiple repetitions, it should be labelled as an estimated 1RM.

Should left and right sides be compared?

Yes. Side-to-side comparison is one of the most useful parts of this test.

Can results be compared across different leg press machines?

Only cautiously. Machine design, seat angle, footplate position and ROM can change the score.

Should pain be recorded?

Yes. Pain score, symptom location, ROM and whether symptoms limited the result should be recorded.

Is a true 1RM always required?

No. A 3RM, 5RM, 8RM or 10RM may be more appropriate for many clients. Measurz can use load and reps to estimate 1RM.

Key Takeaways

The Leg Press – Single Leg Repetition Maximum Test measures unilateral machine-based lower-limb pressing strength.
Measurz calculates the estimated 1RM from the recorded load and reps.
Side, machine setup, foot position and ROM must be repeated for meaningful retesting.
Do not treat an estimated 1RM as the same as a directly measured 1RM.
Do not treat the result as a complete lower-limb strength or sport-readiness profile.
Record load, reps, side, setup, ROM, symptoms and RPE in Measurz.

References

Grgic, J., Lazinica, B., Schoenfeld, B. J., & Pedisic, Z. (2020). Test–retest reliability of the one-repetition maximum strength assessment: A systematic review. Sports Medicine - Open, 6, 31. https://doi.org/10.1186/s40798-020-00260-z

Hoeger, W. W. K., Hopkins, D. R., Barette, S. L., & Hale, D. F. (1990). Relationship between repetitions and selected percentages of one repetition maximum. Journal of Strength and Conditioning Research, 4(2), 47–54.

Suchomel, T. J., Nimphius, S., Bellon, C. R., & Stone, M. H. (2018). The importance of muscular strength: Training considerations. Sports Medicine, 48(4), 765–785.