Different Interset Rest Intervals During the Nordic Hamstrings Exercise in Young Male Athletes

Context: The Nordic hamstring exercise (NHE) is known to reduce hamstrings injury risk in athletes. To optimize the NHE, it is important to understand how acute resistance-training variables influence its performance. Objective: To examine the effects of different interset rest intervals (ISRIs) on force indices during performance of the NHE. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Ten well-trained, young, male, team-sport athletes (age ¼ 20.7 6 2.3 years, height ¼ 179.4 6 5.5 cm, mass ¼ 83.9 6 12.4 kg). Intervention(s): Participants performed 2 sets of 6 repetitions of the NHE with either a 1- or 3-minute ISRI. All sets were performed using the NordBord. Main Outcomes Measure(s): Peak force (newtons), average force (newtons), percentage maintenance, and percentage decline were recorded for both the dominant and nondominant limbs, and interlimb force asymmetries (percentages) were calculated. Results: No interactions or main effects (P . .05) were present between conditions or sets for any variables. However, individual repetitions showed reductions (P, .05; effect size range ¼ 0.58–1.28) in peak force from repetition 4 onward. Conclusions: Our findings suggest that a 1-minute ISRI was sufficient to maintain force-production qualities and interlimb asymmetries between sets during the NHE in well-trained athletes. Nonetheless, practitioners should be aware of the potentially large decrements in peak force production that may occur within the set.