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 = 20.7 ± 2.3 years, height = 179.4 ± 5.5 cm, mass = 83.9 ± 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 = 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.