Abstract This study assessed the effect of a trunk extensor endurance exercise protocol (TEEP) on trunk extensor muscle endurance (TEME) of 42 apparently healthy undergraduates. Subjects in the experimental group exercised once daily four times a week for 6 weeks while those in the control group did not exercise. The trunk extensor endurance of all subjects was assessed at weeks 0, 3 and 6 of the study using a modified Sorensen test. Data were analysed using the SPSS statistical package (version 10) and the alpha level set at 0.05. The two groups did not differ significantly (p ≥ 0.251) in their physical characteristics at baseline. The TEME of the experimental group changed from 178.05 ± 54.69 at week 0 to 289.67 ± 63.55 at week 6 while that of the control group changed from 172.91 ± 54.47 at week 0 to 179.33 ± 56.8 at week 6 of the study. Statistically significant difference (p