A runner may show a clear difference in calf strength between sides. A field sport athlete may need to rebuild plantar-flexion strength after a period of reduced loading. A gym client may be progressing lower-limb strength but still show limited calf strength on one side.
The Seated Calf Raise – Single Leg Repetition Maximum Test provides a controlled way to assess calf strength using a standardised seated calf raise 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 calf function, Achilles tendon capacity, sprint performance, jump performance, lower-limb injury risk or return-to-sport readiness.
Test name: Seated Calf Raise – Single Leg Repetition Maximum Test
Purpose: Assess single-leg seated plantar-flexion strength
What it assesses: Machine-based calf strength, with a seated emphasis on soleus-biased plantar-flexion performance
Equipment: Seated calf raise machine, load stack or plates, Measurz for estimated 1RM calculation
Key finding: Load and repetitions completed, used by Measurz to calculate estimated 1RM
Best used with: Calf endurance testing, ankle ROM, hop tests, sprint testing and lower-limb strength testing
Key limitation: It measures machine-based seated plantar-flexion strength, not complete calf, Achilles or running function
The Seated Calf Raise – Single Leg Repetition Maximum Test measures the heaviest load a client can lift for a defined number of repetitions on one leg using a seated calf raise machine.
Depending on the protocol, this may be a 3RM, 5RM, 8RM, 10RM or another repetition maximum. The target repetition range should be clearly recorded.
In Measurz, the professional records the load and number of completed repetitions. Measurz then calculates the estimated 1RM from that result. This estimated 1RM can be used to monitor progress over time, compare sides and guide training 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.
This test is used to assess unilateral seated calf raise strength, compare sides and track strength changes over time.
It may be useful for athletes, runners, field sport clients, gym clients and lower-limb strength programmes where plantar-flexion strength is an important monitoring variable.
It is especially useful when the professional wants a strength estimate without requiring a maximal 1RM attempt. A submaximal RM test can be more practical for many clients while still giving a useful estimated 1RM through Measurz.
The test measures single-leg seated calf raise performance under the tested machine setup.
It may reflect:
Machine-based plantar-flexion strength
Soleus-biased calf loading capacity
Side-to-side strength difference
Load tolerance
Control through the selected ROM
Pain or symptom response
Estimated 1RM progress across training blocks
It does not measure Achilles tendon capacity, calf endurance, standing calf function, sprint performance, jump performance, ankle stiffness, foot control or injury risk on its own.
This test may be useful for runners, field sport athletes, jumping athletes, gym clients, lower-limb strength clients and people completing calf-focused training.
It may not be appropriate when the machine setup causes pain, the client cannot stabilise the limb safely, the ankle cannot move through a repeatable ROM, symptoms increase during loaded plantar flexion, or the client is not ready for maximal or near-maximal repetition testing.
Seated calf raise machine
Load stack or plates
Adjustable knee pad, foot platform and seat position
Measurz for recording load, reps and estimated 1RM
Optional metronome
Optional video
Optional foot-position marker if the machine setup allows
Set the machine
Adjust the seat, knee pad, foot platform and lever position. Record these settings so the setup can be repeated.
Position the client
Place one foot on the platform with the ball of the foot supported and the heel free to move. The knee should remain under the pad and the tested limb should stay aligned through the movement.
Choose the repetition target
Select the repetition maximum target, such as 3RM, 5RM, 8RM or 10RM. Use the same target for retesting where possible.
Define valid ROM
Set a clear start and finish range. A valid repetition should include controlled lowering into the selected dorsiflexion range and a consistent rise into plantar flexion without bouncing or shortening the movement.
Warm up
Complete light warm-up sets on each side. Increase load gradually before testing.
Test one side at a time
Choose the testing order and keep it consistent. Allow adequate rest between attempts and sides.
Record the maximum successful set
The score is the heaviest load completed for the target repetition range with acceptable technique, ROM and control.
Enter load and reps into Measurz
Record the completed load and repetitions in Measurz. Measurz calculates the estimated 1RM from the entered result.
Record the load, reps and side tested. 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
Tempo
RPE
Pain or symptoms
Compensations
Previous baseline
A lower estimated 1RM on one side may suggest reduced machine-based seated plantar-flexion strength under the tested setup, but it does not identify the cause. Pain, fatigue, ankle ROM, machine fit, foot placement, confidence, recent training and tendon symptoms may all influence the result.
No universal normative value should be applied across machines and populations. Seated calf raise results vary by machine design, knee angle, foot platform, lever arm, ROM, body size, training history and whether the 1RM is directly measured or estimated.
Use baseline comparison, limb symmetry and progress across sessions as the primary benchmarks.
For unilateral testing, side-to-side comparison can be useful, but it should not be treated as a strict pass/fail rule. A noticeable difference between sides should be interpreted alongside symptoms, sport or training demands, ROM, calf endurance and related lower-limb tests.
Common errors include changing seat settings, changing knee pad position, using inconsistent ROM, bouncing out of the bottom position, shortening the top range, allowing the foot to slide, rotating the hip, using momentum, changing tempo, testing while fatigued and comparing results across different 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 seated plantar-flexion strength only. It does not fully assess calf endurance, standing calf strength, Achilles capacity, sprinting, jumping or running performance.
Use this test to monitor single-leg calf strength, compare sides, guide training loads and track response to calf-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 paired with standing calf raise testing, single-leg calf raise endurance, ankle ROM, hop testing, sprint exposure, jump testing and symptom monitoring.
Record side tested, machine type, seat setting, knee pad setting, foot position, ROM, load, reps, RM target, estimated 1RM, RPE, pain score, symptom location, compensation notes, comparison side and retest date.
Useful notes include shortened ROM, heel drop depth, poor top-range lift, bouncing, foot slip, cramping, Achilles discomfort, pain-limited rep, fatigue-limited attempt, tempo change or side-to-side difference.
The key Measurz workflow is:
Enter the completed load
Enter the completed reps
Review the estimated 1RM calculated by Measurz
Record side, setup, ROM, symptoms and compensations
Use the same protocol for retesting
It measures single-leg machine-based seated plantar-flexion strength.
It provides useful soleus-biased calf strength information because the knee is flexed, but it does not isolate the soleus completely.
The professional enters the completed load and reps into Measurz. Measurz uses this information to calculate the estimated 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.
Yes. Side-to-side comparison is one of the most useful parts of this test.
Only cautiously. Machine design, lever arm, knee pad position and ROM can change the score.
Yes. Pain score, symptom location, ROM and whether symptoms limited the result should be recorded.
No. A 3RM, 5RM, 8RM or 10RM may be more appropriate for many clients. Measurz can use load and reps to estimate 1RM.
The test measures unilateral seated calf raise repetition maximum performance.
Measurz calculates the estimated 1RM from the recorded load and reps.
Machine setup and ROM must be repeated.
Do not treat an estimated 1RM as the same as a directly measured 1RM.
Do not treat the result as a complete calf, Achilles or running profile.
Record load, reps, side, ROM, symptoms, RPE and setup in Measurz.
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
Hébert-Losier, K., Wessman, C., Alricsson, M., & Svantesson, U. (2017). Updated reliability and normative values for the standing heel-rise test in healthy adults. Physiotherapy, 103(4), 446–452.
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.
