Accuracy of Prediction Equations to Calculate Maximum Strength

January 28, 2026 updated by: Wolfgang Kemmler, PhD, University of Erlangen-Nürnberg Medical School

Accuracy of a New Prediction Equation to Calculate One Repetition Maximum (1RM) in Trained and Untrained Young and Old Adults

Resistance exercise training (RT) is a key component of health related exercise programs. However, an accurate specification of RT load prescription is essential for effective and safe achievement of training aims. Proper specification of exercise intensity might be the most critical issue when designing RT protocols for adults. One repetition maximum tests (1RM) have been considered the "gold standard" of dynamic maximum strength evaluation. Although the argument of increased risk of injuries and adverse effects with 1RM testing in older people has been rejected by several studies , limited motivation to lift maximum loads, requirement for high test effort, time constraints, and interruption of the continuity of the training process aggravate the frequent application of 1RM tests particularly in non-athletic RT. 1RM prediction equations that use the load and number of repetitions completed to fatigue (RTF) to predict repetition maximum might be a reliable and feasible option to 1RM testing. Thus, the primary aims of this study were to evaluate the predictive accuracy of current RTF equations and to develop an equation that more accurately predicts 1RM from RTF tests.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Germany
      • Erlangen, Germany, 91054
        • Institute of Radiology, University Hospital NErlangen

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population consists of resistance trained and untrained women and men 18 to 35 or 60-85 years old that are able to complete 1RM and RTF tests without endangering their health

Description

Inclusion Criteria:

  • 18 to 35 years old
  • 60 to 85 years old

Exclusion Criteria:

  • Contraindication for one repetition maximum tests
  • musculoskeletal injuries that may prevent a reliable and safe assessment of the 1RM and RTF tests

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Maximum load, one repetition maximum, leg press
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the leg press exercise
At baseline - no follow up tests

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Maximum load lifted at 5-8RM, leg press
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the leg press exercise
At baseline - no follow up tests
Maximum load lifted at 9-12RM, leg press
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT9-12, in kg) for the leg press exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, leg press
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT13-16, in kg) for the leg press exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, lat pulls
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the latissimus pull exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, lat pulls
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the latissimus pull exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, lat pulls
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the latissimus pull exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, lat pulls
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the latissimus pull exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, triceps dips
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the triceps dips exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, triceps dips
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the triceps dips exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, triceps dips
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the triceps dips exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, triceps dips
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the triceps dips exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, trunk extension
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the trunk extension exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, trunk extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the trunk extension exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, trunk extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the trunk extension exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, trunk extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the trunk extension exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, trunk flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the trunk flexion exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, trunk flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the trunk flexion exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, trunk flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the trunk flexion exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, trunk flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the trunk flexion exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, leg flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the leg flexion exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, leg flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the leg flexion exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, leg flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the leg flexion exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, leg flexion
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the leg flexion exercise
At baseline - no follow up tests
Maximum load, one repetition maximum, leg extension
Time Frame: At baseline - no follow up tests
Maximum load lifted once (1RM, in kg) for the leg extension exercise
At baseline - no follow up tests
Maximum load lifted at 5-8 RM, leg extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 5-8 times (RFT5-8, in kg) for the leg extension exercise
At baseline - no follow up tests
Maximum load lifted at 9-12 RM, leg extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 9-12 times (RFT9-12, in kg) for the leg extension exercise
At baseline - no follow up tests
Maximum load lifted at 13-16 RM, leg extension
Time Frame: At baseline - no follow up tests
Maximum load lifted 13-16 times (RFT13-16, in kg) for the leg extension exercise
At baseline - no follow up tests

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Erlangen-Nürnberg Medical School

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 2, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 1, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 4, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 5, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 29, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PREDEQ
  • Physiomed ID 101 (Other Identifier: UKER - FAU)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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