Context: Roller massagers are used as a recovery and rehabilitative tool to initiate muscle relaxation and improve range of motion (ROM) and muscular performance. However, research demonstrating such effects is lacking.Objective: To determine the effects of applying a roller massager for 20 and 60 seconds on knee-joint ROM and dynamic muscular performance.Design: Randomized controlled clinical trial. Setting: University laboratory.Patients or Other Participants: Ten recreationally active men (age ¼ 26.6 6 5.2 years, height ¼ 175.3 6 4.3 cm, mass ¼ 84.4 6 8.8 kg).Intervention(s): Participants performed 3 randomized experimental conditions separated by 24 to 48 hours. In condition 1 (5 repetitions of 20 seconds) and condition 2 (5 repetitions of 60 seconds), they applied a roller massager to the quadriceps muscles. Condition 3 served as a control condition in which participants sat quietly.Main Outcome Measure(s): Visual analog pain scale, electromyography (EMG) of the vastus lateralis (VL) and biceps femoris during roller massage and lunge, and kneejoint ROM.Results: We found no differences in pain between the 20-second and 60-second roller-massager conditions. During 60 seconds of roller massage, pain was 13.5% (5.7 6 0.70) and 20.6% (6.2 6 0.70) greater at 40 seconds and 60 seconds, respectively, than at 20 seconds (P , .05). During roller massage, VL and biceps femoris root mean square (RMS) EMG was 8% and 7%, respectively, of RMS EMG recorded during maximal voluntary isometric contraction. Knee-joint ROM was 10% and 16% greater in the 20-second and 60-second roller-massager conditions, respectively, than the control condition (P , .05). Finally, average lunge VL RMS EMG decreased as roller-massage time increased (P , .05).Conclusions: Roller massage was painful and induced muscle activity, but it increased knee-joint ROM and neuromuscular efficiency during a lunge.Key Words: electromyography, pain, muscle activation, flexibility, stretch Key PointsA roller massager applied to the quadriceps at a load equal to 25% of body mass was moderately painful and induced minor contractions. The combination of active contractions and 20 to 60 seconds of roller massage improved knee-joint range of motion and reduced vastus lateralis electromyographic activity during a lunge. Roller massage could be used to increase range of motion during a warm-up or as a complement to stretching during flexibility training sessions. M any researchers have studied how stretching affects range of motion (ROM) and performance; in general, their results showed increased ROM and impairments in subsequent performance.1,2 Recently introduced alternative devices to stretching include the foam roller and roller massager. The use of these devices has produced increases in ROM.3,4 Authors of 2 studies examined how a foam roller affects flexibility.3,5 MacDonald et al 3 reported 12.7% and 10.3% increases in knee-joint ROM at 2 minutes and 10 minutes, respectively, after two 1-minute bouts of foam rolling. MacDonald et al 5 found that quadriceps ROM ...

The objective of this study was to determine how a high-intensity circuit-training (HICT) program affects key physiological health markers in sedentary obese men. Eight obese (body fat percentage >26%) males completed a four-week HICT program, consisting of three 30-minute exercise sessions per week, for a total of 6 hours of exercise. Participants' heart rate (HR), blood pressure (BP), rating of perceived exertion, total work (TW), and time to completion were measured each exercise session, body composition was measured before and after HICT, and fasting blood samples were measured before throughout, and after HICT program. Blood sample measurements included total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, and insulin. Data were analyzed by paired t-tests and one-way ANOVA with repeated measures. Statistical significance was set to P < 0.05. Data analyses revealed significant (P < 0.05) improvements in resting HR (16% decrease), systolic BP (5.5% decrease), TW (50.7%), fat tissue percentage (3.6%), lean muscle tissue percentage (2%), cholesterol (13%), triacylglycerol (37%), and insulin (18%) levels from before to after HICT program. Overall, sedentary obese males experienced a significant improvement in biochemical, physical, and body composition characteristics from a HICT program that was only 6 hours of the total exercise.