Following these initial 15 sets in which the repetition number was standardized, subjects performed 3 sets of repetitions to failure at 70% 1-RM, with 3 minutes of rest between each set. The total number of repetitions performed was counted and used as an indicator of total work performed (reps x load = volume load). Before and following the completion of the exercise test, outcome measures

were assessed as indicated below. It should be noted that the exercise protocol used in this study is similar in volume as other exercise MK-4827 research buy protocols used to induce muscle fatigue. However, to our knowledge, this exact protocol has not been used in other published work focused on muscle injury and oxidative stress, but was developed based on general resistance https://www.selleckchem.com/products/cb-5083.html exercise guidelines presented in published form [13]. In hindsight, although the protocol was of similar volume as those used in past studies of muscle injury and oxidative stress, the overall intensity of work may not have been great enough to induce adequate muscle damage and oxidative stress, as the ideal protocol may have included not only

high volume exercise but also high force exercise (i.e., pure eccentric muscle actions), which are known to induce significant muscle trauma [14]. Outcome measures All outcome measures were determined both pre and post intervention (i.e., before and after intake of MSM). As described in past research [15, 16], muscle soreness was determined using a visual analog scale: In this study we used a 5-point Likert scale (0 = no soreness at all; 4 = very sore). The muscle Thalidomide soreness questionnaire was administered before exercise and 2 and 48 hours following the knee SB525334 extension protocol with subjects reporting the level of soreness in their legs (quadriceps) “right now.” In addition to muscle soreness, fatigue

was determined using a distinct questionnaire—the fatigue-inertia subset of the Profile of Mood States [17, 18], which includes a 5-point Likert scale (0 = not at all, 1 = a little, 2 = moderately, 3 = quite a bit, 4 = extremely). The fatigue questionnaire was also administered before exercise and 2 and 48 hours post-exercise with subjects reporting their level of fatigue “right now.” Although some overlap may be present in individuals’ view and rating of soreness and fatigue, our questionnaires were distinct and clearly represented either soreness or fatigue, both of which were rated by subjects. Exercise performance during the final three sets of knee extension was determined based on total volume load (reps x load). Heart rate and blood pressure were measured, and venous blood was collected from subjects before exercise, immediately post-exercise, and two hours post-exercise. Blood from tubes containing EDTA was used for total (TGSH) and oxidized (GSSG) glutathione analysis.