The Influence of Phototherapy on Recovery From Exercise-Induced Muscle Damage.

Background: Intense physical activity can result in exercise-induced muscle damage, delayed-onset muscle soreness, and decrements in performance. Phototherapy (PhT), sometimes referred to as photobiomodulation or low-level laser therapy, may enhance recovery from vigorous exercise. Purpose: The purpose of this study was to assess the influence of phototherapy on functional movements (vertical jump, agility), and perceptions of muscle soreness following exercise-induced muscle damage caused by high volume sprinting and decelerations. Methods: In a between-group design, 33 participants performed 40x15m sprints, a protocol intended to cause muscle damage. Immediately following sprinting and in the four days following, vertical jump and agility were assessed, as well as calf, hamstring, quadriceps, and overall perceptions of soreness. Sixteen subjects (age 20.6±1.6 yrs; BMI 25.8±4.6 kg.m-2) received PhT prior to testing each day, while 17 (age 20.8±1.3 yrs; BMI 26.2±4.5 kg.m-2) received sham PhT and served as a control (CON). Measurements were recorded during five days of recovery from the repeated sprint protocol, then compared to those recorded during three baseline days of familiarization. Area under the curve was calculated by summing all five scores, and comparing those values by condition via a two-tailed unpaired t-test for normally distributed data, and a two-tailed Mann-Whitney U test for nonparametric data (alpha level = 0.05). Results: Calf soreness was lower in PhT compared to CON (p = 0.02), but no other significant differences were observed between groups for vertical jump, agility, quadriceps, hamstring, and overall soreness (p > 0.05). Discussion: Phototherapy may attenuate soreness in some muscle groups following exercise-induced muscle damage, but may not enhance recovery after explosive, short-duration activities. Conclusion: Phototherapy may not be a useful recovery tool for those participating in explosive, short-duration activities. Level of evidence: 2c.

Influence of Foam Rolling on Recovery From Exercise-Induced Muscle Damage.

D'Amico, AP and Gillis, J. Influence of foam rolling on recovery from exercise-induced muscle damage. J Strength Cond Res 33(9): 2443-2452, 2019-The purpose of this study was to examine the impact of foam rolling (FR) on recovery from exercise-induced muscle damage (EIMD). Thirty-seven male individuals performed 40 × 15-m sprints, inducing muscle damage. Immediately after sprinting and in the 4 days following, perceived muscle soreness, hip abduction range of motion (ROM), hamstring muscle length, vertical jump (VJ), and agility measures were recorded. Eighteen subjects (mean ± SD; age 22.4 ± 2.0 years; BMI [body mass index] 26.9 ± 4.2 kg·m) foam rolled before testing each day, whereas 19 (mean ± SD; age 23.2 ± 3.2 years; BMI 26.3 ± 4.0 kg·m) served as a non-FR control (CON). Measurements recorded during the 5 days of recovery from the repeated sprint protocol were compared with week 1 baseline measurements. The area under the curve (AUC) was calculated by summing all 5 scores as they changed from baseline measurement, and these data were compared by condition using a 2-tailed Mann-Whitney U-test (alpha level = 0.05). Perceived soreness, hip abduction ROM, hamstring muscle length, and VJ were not significantly different between groups (p ≥ 0.25). Agility was less impaired in the FR condition (p = 0.0049) as AUC was higher in CON (2.88 ± 2.45 seconds) than in FR (0.33 ± 2.16 seconds). Based on these data, FR appears to expedite recovery of agility after EIMD instigated by a repeated sprint protocol. Foam rolling may be useful for athletes requiring adequate agility who need to recover quickly from demanding bouts of exercise.

Association Between Anaerobic Metabolic Demands During Simulated Brazilian Jiu-Jitsu Combat and Specific Jiu-Jitsu Anaerobic Performance Test.

Villar, R, Gillis, J, Santana, G, Pinheiro, DS, and Almeida, ALRA. Association between anaerobic metabolic demands during simulated Brazilian jiu-jitsu combat and specific jiu-jitsu anaerobic performance test. J Strength Cond Res 32(2): 432-440, 2018-The aims of this study were to design a specific Jiu-Jitsu anaerobic performance test (JJAPT) and investigate the relationship between blood lactate ([La]), heart rate (HR), and rating of perceived exertion (RPE) during simulated Brazilian Jiu-Jitsu combat (SBJJC) and JJAPT. Nine male elite Brazilian medium heavy weight athletes performed a 10-minute SBJJC and JJAPT that required performance of a common BJJ technique for 5 consecutive bouts of 1-minute with 45-second rest between bouts. [La] was measured by a lactate analyzer, HR by an HR monitor, and RPE using Borg's scale, and the number of repetitions of butterfly lifts (NBL) was recorded. During JJAPT, NBL decreased in the fourth and fifth bouts (p ≤ 0.05) with increases in [La], HR, and RPE (p ≤ 0.05), indicating that the JJAPT measured anaerobic performance. [La] during SBJJC was not different than [La] at the third and fourth bouts, but was significantly different than the fifth bout (p ≤ 0.05). [La] showed strong correlation between SBJJC and JJAPT for the third (r = 0.80, p ≤ 0.05), fourth (r = 0.83, p ≤ 0.05), and fifth (r = 0.82, p ≤ 0.05) bouts, but not between the HR and RPE. The JJAPT with 4 bouts presented the best combination of stimulus and highest correlation with SBJJC, supporting its use to assess anaerobic performance of BJJ athletes. These data will aid coaches and athletes to better understand the demands of their sport and may help to monitor adaptation in sport-specific performance across periodized training plans.