One Rep Max

Measured and estimated 1RM

A one-repetition maximum is the greatest load completed once for a specified exercise under a defined technique and range. It is exercise- and protocol-specific. An estimated 1RM uses repetitions at a submaximal load and an equation; it is an estimate whose error varies by exercise, repetition count and population.

ACSM resistance-training position stand 2026 · 1RM test-retest reliability systematic review · 1RM prediction equations systematic review

Testing and use

Use suitable equipment, progressive warm-up attempts and adequate rest under competent supervision when maximal testing is appropriate. Novices, symptomatic athletes or people without a need for maximal testing can use submaximal measures. A 1RM can guide loading and track exercise-specific strength, but it does not by itself predict HYROX^® performance or require a universal retest schedule.

ACSM resistance-training position stand 2026 · 1RM test-retest reliability systematic review · 1RM prediction equations systematic review

FAQ

Is estimated 1RM exact?

No. It is an equation-based estimate.

ACSM resistance-training position stand 2026 · 1RM test-retest reliability systematic review · 1RM prediction equations systematic review

Must everyone test a true 1RM?

No. Submaximal assessment may be more appropriate.

ACSM resistance-training position stand 2026 · 1RM test-retest reliability systematic review · 1RM prediction equations systematic review

Does 1RM predict HYROX^® time?

No. It measures exercise-specific maximal strength.

ACSM resistance-training position stand 2026 · 1RM test-retest reliability systematic review · 1RM prediction equations systematic review

Marketing text preserved unchanged

Calculate your estimated 1RM and track strength progress at Repz.