None of the participants had performed regular leg strength exercise in the previous 3 months. These criteria were created in order to avoid protection selleck chemicals against DOMS from repeated bouts of resistance exercise. Eligible participants were randomly assigned into one of three groups; a warm-up group, a cool-down group, and a control group. Group characteristics at baseline according to group allocation are presented in Table 1. The allocation of participants was performed by random draw with men and women being assigned separately. The study was approved by the Regional Committee for Medical and Health Research Ethics (S-2009/1739-1, REK midt, Norway) and carried out in accordance with the Declaration of Helsinki. Table 1 Group characteristics at baseline according to group allocation.
Measures and Procedures Measurements were carried out on three consecutive weekdays with similar test time on each day (<2 hours difference between days). All participants performed a bout of front lunges on day 1. This resistance exercise imposes eccentric lengthening of the quadriceps muscle during the braking phase but also requires a concentric effort during the push-off phase. Precise and consistent description about the performance technique was given to each participant. The exercise was standardized by marking the individual stride length in the bottom position of the lunge when assuming a ~90�� angle in the knee and hip joint of the forward stepping leg. The exercise was performed with the dominant leg only, i.e., the forward stepping leg, in 5 sets with 10 repetitions with 30 sec rest between each set.
A metronome was used to ensure participants maintained a cadence of 10 lunges per 30 sec. External load was provided by a barbell held behind the neck on top of the shoulders. The load was set to 40% and 50% of the body mass for woman and men, respectively. Recordings of pressure pain threshold (PPT), maximal knee extension force during maximal voluntary isometric contraction (MVC), and subjective ratings of muscle soreness on a visual analogue scale (VAS) were carried out before the front lunge exercise (day 1), 24 hours after exercise (day 2), and 48 hours after exercise (day 3). All recordings were carried out for the exercised leg only. Prior to the front lunge exercise on day 1, the warm-up group completed 20 min of moderate intensity aerobic exercise.
Conversely, for the cool-down group, the front lunge exercise was followed by 20 min of moderate intensity aerobic exercise. The control group AV-951 only performed the front lunge exercise. The warm-up and cool-down were done on a cycle ergometer (Monark 939E, Vansbro, Sweden). The first 5 min of cycling was used to adjust the workload to correspond to ~65% of estimated maximum heart rate (HRmax adjusted for age; 220-age * 0.65). The last 15 min was performed at a workload of 60�C70% of HRmax with a cadence of 65�C75 rpm.