Cross-validity of one maximum repetition predictive equation for men with spinal cord injury

Objectives: The study aimed to test the cross-validation of a specific one maximum repetition (1RM) predictive equation based on the 4- to 12-maximum repetition test (4-12RM) for men with spinal cord injury (SCI).

Study design: Cross-sectional study.

Setting: Rehabilitation Hospital Network.

Participants: Fifty-eight men aged 31.9 (20.0–38.0) years (median and quartile) with SCI were enrolled in the study.

Interventions: None.

Outcomes measures: Volunteers were tested in 1RM test or 4-12RM of the bench press exercise with 2–3 interval days in a random order. The intraclass correlation coefficient (ICC) with Bland Altman plot was used to compare a specific predictive equation (SPE) and six current predictive equations (CPE) based on the 4- to 12-maximum repetition with the 1RM test.

Results: The SPE showed the highest intraclass correlation coefficient (ICC?=?0.91; 95%CI 0.85–0.95), the smallest range of the interval around the differences (Δ?=?36.6) and the second lowest mean difference between 1RM test and 1RM predictive equation (?2.4?kg). The CPE3 presented the lowest mean difference (?1.6?kg). All intraclass correlations’ predictive equations were classified as excellent.

Conclusion: The SPE presented a suitable and satisfactory validity to assess men with SCI at the bench press exercise. Thus, the equation is an accurate method to predict 1RM in SCI.