Search Results

You are looking at 61 - 70 of 227 items for :

  • "muscle damage" x
Clear All
Restricted access

Matthew Finberg, Rebecca Braham, Carmel Goodman, Peter Gregory and Peter Peeling

Purpose:

To assess the efficacy of a 1-off electrostimulation treatment as a recovery modality from acute teamsport exercise, directly comparing the benefits to contrast water therapy.

Methods:

Ten moderately trained male athletes completed a simulated team-game circuit (STGC). At the conclusion of exercise, participants then completed a 30-min recovery modality of either electrostimulation therapy (EST), contrast water therapy (CWT), or a passive resting control condition (CON). Twenty-four hours later, participants were required to complete a modified STGC as a measure of next-day performance. Venous blood samples were collected preexercise and 3 and 24 h postexercise. Blood samples were analyzed for circulating levels of interleukin-6 (IL-6) and C-reactive protein (CRP).

Results:

The EST trial resulted in significantly faster sprint times during the 24-h postrecovery than with CON (P < .05), with no significant differences recorded between EST and CWT or between CWT and CON (P > .05). There were no differences in IL-6 or CRP across all trials. Finally, the perception of recovery was significantly greater in the EST trial than in the CWT and CON (P < .05).

Conclusions:

These results suggest that a 1-off treatment with EST may be beneficial to perceptual recovery, which may enhance next-day performance.

Restricted access

Melissa Skein, Rob Duffield, Geoffrey M. Minett, Alanna Snape and Alistair Murphy

Purpose:

This study examined the effects of overnight sleep deprivation on recovery after competitive rugby league matches.

Methods:

Eleven male amateur rugby league players played 2 competitive matches, followed by either a normal night’s sleep (~8 h; CONT) or a sleep-deprived night (~0 h; SDEP) in a randomized fashion. Testing was conducted the morning of the match, immediately postmatch, 2 h postmatch, and the next morning (16 h postmatch). Measures included countermovement-jump (CMJ) distance, knee-extensor maximal voluntary contraction (MVC) and voluntary activation (VA), venous-blood creatine kinase (CK) and C-reactive protein (CRP), perceived muscle soreness, and a word–color recognition cognitive-function test. Percent change between postmatch and 16-h postmatch was reported to determine the effect of the intervention the next morning.

Results:

Large effects indicated a greater postmatch to 16-h-postmatch percentage decline in CMJ distance after SDEP than in CONT (P = .10–.16, d = 0.95–1.05). Similarly, the percentage decline in incongruent word–color reaction times was increased in SDEP trials (P = .007, d = 1.75). Measures of MVC did not differ between conditions (P = .40–.75, d = 0.13–0.33), although trends for larger percentage decline in VA were detected in SDEP (P = .19, d = 0.84). Furthermore, large effects indicated higher CK and CRP responses 16 h postmatch in SDEP than in CONT (P = .11–.87, d = 0.80–0.88).

Conclusions:

Sleep deprivation negatively affected recovery after a rugby league match, specifically impairing CMJ distance and cognitive function. Practitioners should promote adequate postmatch sleep patterns or adjust training demands the next day to accommodate the altered physical and cognitive state after sleep deprivation.

Restricted access

Mary P. Miles, Erin E. Walker, Stephen B. Conant, Shelly P. Hogan and Jessy R. Kidd

Attenuation of exercise-induced interleukin-6 (IL-6) responses by carbohydrate (CHO) has been demonstrated in studies comparing controlled doses (≥ 0.9 g · kg−1 · h−1) to placebo, but not in studies of voluntary intake. This study sought to determine if attenuation of the IL-6 response during a 32.2-km mountain trail race occurs for high compared to low ad libitum CHO intakes. IL-6, C-reactive protein (CRP), and creatine kinase activity (CK) were analyzed from blood samples collected 12 h pre-, 0, 4, and 24 h post-race. Subjects were grouped into low (n = 14, 0.4 ± 0.1 g · kg−1· h−1) and high (n = 18, 0.8 ± 0.2 g · kg−1 · h−1) CHO intake groups. IL-6 0 h post-race (P < 0.05) was higher in the low (40.2 ± 22.7 pg · mL−1) compared to the high CHO group (32.7 ± 22.1 pg · mL−1). CRP and CK both increased post-race, but no differences were observed between groups. Attenuation of exercise-induced IL-6 is apparent across a range of CHO intakes.

Restricted access

Mike I. Lambert, Lise Bryer, David B. Hampson, Les Nobbs, Andrea M. Rapolthy, M. Sharhidd Taliep and L. Wayne Viljoen

The aim of this study was to measure the change in running performance in a runner from age 27–64 years. During this time the runner had a history of high-volume training and racing. The change in his average running speed over 10-, 21.1-, 42.2-, and 90-km races was compared with the changes in the age-group records for each distance. He trained an average of 4,051 ± 1,762 km/year and ran 16,604 km during races. His training load reached a peak of 7,596 km/year at the age of 33. His rate of decline in running performance was higher than the expected age decline at 47 years for 10-km, 47 years for 21.1-km, 40 years for the 42.2-km, and 48 years for 90-km races. Decreases in performance with increasing age could be explained by reduced training volume, or, alternatively, high volumes of training and racing might accelerate the normal age-related decrements in running performance.

Restricted access

Michael S. Green, J. Andrew Doyle, Christopher P. Ingalls, Dan Benardot, Jeffrey C. Rupp and Benjamin T. Corona

This study determined whether disrupted glucose and insulin responses to an oral glucose-tolerance test (OGTT) induced by eccentric exercise were attenuated after a repeated bout. Female participants (n = 10, age 24.7 ± 3.0 yr, body mass 64.9 ± 7.4 kg, height 1.67 ± 0.02 m, body fat 29% ± 2%) performed 2 bouts of downhill running (DTR 1 and DTR 2) separated by 14 d. OGTTs were administered at baseline and 48 hr after DTR 1 and DTR 2. Maximum voluntary isometric quadriceps torque (MVC), subjective soreness (100-mm visual analog scale), and serum creatine kinase (CK) were assessed pre-, post-, and 48 hr post-DTR 1 and DTR 2. Insulin and glucose area under the curve (38% ± 8% and 21% ± 5% increase, respectively) and peak insulin (44.1 ± 5.1 vs. 31.6 ± 4.0 μU/ml) and glucose (6.5 ± 0.4 vs. 5.5 ± 0.4 mmol/L) were elevated after DTR 1, with no increase above baseline 48 hr after DTR 2. MVC remained reduced by 9% ± 3% 48 hr after DTR 1, recovering back to baseline 48 hr after DTR 2. Soreness was elevated to a greater degree 48 hr after DTR 1 (48 ± 6 vs. 13 ± 3 mm), with a tendency for greater CK responses 48 hr after DTR 1 (813 ± 365 vs. 163 ± 43 U/L, p = .08). A novel bout of eccentric exercise confers protective effects, with subsequent bouts failing to elicit disruptions in glucose and insulin homeostasis.

Restricted access

Dylan Thompson, Clyde Williams, Stephen J. McGregor, Ceri W. Nicholas, Frank McArdle, Malcolm J. Jackson and Jonathan R. Powell

The aim of the present study was to investigate whether 2 weeks of vitamin C supplementation affects recovery from an unaccustomed bout of exercise. Sixteen male subjects were allocated to either a placebo (P; n = 8) or vitamin C group (VC; n = 8). The VC group consumed 200 mg of ascorbic acid twice a day, whereas the P group consumed identical capsules containing 200 mg of lactose. Subjects performed a prolonged (90-min) intermittent shuttle-running test 14 days after supplementation began. Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation. However, vitamin C supplementation had modest beneficial effects on muscle soreness, muscle function, and plasma concentrations of malondialdehyde. Furthermore, although plasma interleukin-6 increased immediately after exercise in both groups, values in the VC group were lower than in the P group 2 hours after exercise (p < .05). These results suggest that prolonged vitamin C supplementation has some modest beneficial effects on recovery from unaccustomed exercise.

Restricted access

Eduardo Lusa Cadore, Miriam González-Izal, Rafael Grazioli, Igor Setuain, Ronei Silveira Pinto and Mikel Izquierdo

adaptations, and eccentric contractions are characterized by greater muscle force output, high rehabilitation capacity, and greater muscle damage (ie, providing a protective effect). This greater muscle damage causes muscle stiffness and soreness in untrained subjects in the days following the exercise, 4 – 6

Open access

Eric S. Rawson, Mary P. Miles and D. Enette Larson-Meyer

response to exercise via increased growth factor/gene expression, increased intracellular water; reduced symptoms of or enhanced recovery from muscle damaging exercise (e.g., DOMS); enhanced recovery from disuse, immobilization, or extreme inactivity such as after injury; improved cognitive processing

Restricted access

Matthew David Cook and Mark Elisabeth Theodorus Willems

.g., thiobarbituric acid reactive substances, total antioxidant status, lipid hydroperoxides, and protein carbonyls) and inflammation (e.g., interleukin 6, tumor necrosis factor α, C-reactive protein) following muscle-damaging and metabolically demanding exercise ( Bell et al., 2014 , 2015 , 2016 ; Howatson et

Restricted access

Jesús Seco-Calvo, Juan Mielgo-Ayuso, César Calvo-Lobo and Alfredo Córdova

physical agent. 2 , 3 Both muscle fatigue and muscle damage are known to have specific underlying mechanisms that reduce muscle strength and work capacity, such as impairment of glycogen storage, sarcomere disruption, increases in muscle protein breakdown, and inflammatory responses. 5 In addition, the