Effects of heat acclimation on hand cooling efficacy following exercise in the heat.

This study examined the separate and combined effects of heat acclimation and hand cooling on post-exercise cooling rates following bouts of exercise in the heat. Seventeen non-heat acclimated (NHA) males (mean ± SE; age, 23 ± 1 y; mass, 75.30 ± 2.27 kg; maximal oxygen consumption [VO2 max], 54.1 ± 1.3 ml·kg-1·min-1) completed 2 heat stress tests (HST) when NHA, then 10 days of heat acclimation, then 2 HST once heat acclimated (HA) in an environmental chamber (40°C; 40%RH). HSTs were 2 60-min bouts of treadmill exercise (45% VO2 max; 2% grade) each followed by 10 min of hand cooling (C) or no cooling (NC). Heat acclimation sessions were 90-240 min of treadmill or stationary bike exercise (60-80% VO2 max). Repeated measures ANOVA with Fishers LSD post hoc (α < 0.05) identified differences. When NHA, C (0.020 ± 0.003°C·min-1) had a greater cooling rate than NC (0.013 ± 0.003°C·min-1) (mean difference [95%CI]; 0.007°C [0.001,0.013], P = 0.035). Once HA, C (0.021 ± 0.002°C·min-1) was similar to NC (0.025 ± 0.002°C·min-1) (0.004°C [-0.003,0.011], P = 0.216). Hand cooling when HA (0.021 ± 0.002°C·min-1) was similar to when NHA (0.020 ± 0.003°C·min-1) (P = 0.77). In conclusion, when NHA, C provided greater cooling rates than NC. Once HA, C and NC provided similar cooling rates.

Sex differences in creatine kinase after acute heavy resistance exercise on circulating granulocyte estradiol receptors.

Previous research has shown reduced tissue disruption and inflammatory responses in women as compared to men following acute strenuous exercise. While the mechanism of this action is not known, estrogen may reduce the inflammatory response through its interaction with granulocytes. The purpose of this study was to determine if estrogen receptor ß expression on granulocytes is related to sex differences in tissue disruption in response to an acute heavy resistance exercise protocol. Seven healthy, resistance-trained, eumenorrheic women (23 ± 3 years, 169 ± 9.1 cm, 66.4 ± 10.5 kg) and 8 healthy, resistance-trained men (25 ± 5 years, 178 ± 6.7 cm, 82.3 ± 9.33 kg) volunteered to participate in the study. Subjects performed an acute resistance exercise test consisting of six sets of five squats at 90% of the subject's one repetition maximum. Blood samples were obtained pre-, mid-, post-, and 1-, 6-, and 24-h postexercise. Blood samples were analyzed for 17-ß-estradiol by ELISA, creatine kinase by colorimetric enzyme immunoassay, and estradiol receptors on circulating granulocytes through flow cytometry. Men had higher CK concentrations than women at baseline/control. Men had significantly higher CK concentrations at 24-h postexercise than women. No significant changes in estradiol ß receptors were expressed on granulocytes after exercise or between sexes. While sex differences occur in CK activity in response to strenuous eccentric exercise, they may not be related to estradiol receptor ß expression on granulocytes. Thus, although there are sex differences in CK expression following acute resistance exercise, the differences may not be attributable to estrogen receptor ß expression on granulocytes.

A multi-nutrient supplement reduced markers of inflammation and improved physical performance in active individuals of middle to older age: a randomized, double-blind, placebo-controlled study.

BACKGROUND: While exercise acts to combat inflammation and aging, the ability to exercise may itself be compromised by inflammation and inflammation's impact on muscle recovery and joint inflammation. A number of nutritional supplements have been shown to reduce inflammation and improve recovery. The purpose of the current investigation was to examine the effect of a multi-nutrient supplement containing branched chain amino acids, taurine, anti-inflammatory plant extracts, and B vitamins on inflammatory status, endothelial function, physical function, and mood in middle-aged individuals. METHODS: Thirty-one healthy and active men (N = 16, mean age 56 ± 6.0 yrs) and women (N = 15, mean age = 52 ± 7.5 yrs) participated in this investigation. Subjects completed one 28 day cycle of placebo supplementation and one 28 day cycle of multi-nutrient supplementation (separated by a one week washout period) in a balanced, randomized, double-blind, cross-over design. Subjects completed weekly perceptual logs (PROMIS-57, KOOS) and pre- and post- testing around the supplementation period. Testing consisted of brachial artery flow mediated dilation (FMD), blood measures, and physical performance on vertical jump, handgrip strength, and balance (dispersion from center of pressure). Significance for the investigation was p ≤ 0.05. RESULTS: IL-6 significantly decreased in both men (from 1.2 ± 0.2 to 0.7 ± 0.4 pg·mL(-1)) and women (from 1.16 ± 0.04 to 0.7 ± 0.4 pg·mL(-1)). Perceived energy also improved for both men (placebo: 1.8 ± 0.7; supplement: 3.7 ± 0.8 AUC) and women (placebo: 1.2 ± 0.7; supplement: 2.8 ± 0.8 AUC). Alpha-1-antichymotrypsin (from 108.9 ± 38.6 to 55.5 ± 22.2 ug·mL(-1)), Creatine Kinase (from 96 ± 34 to 67 ± 23 IU·L(-1)), general pain, and joint pain decreased in men only, while anxiety and balance (from 0.52 ± 0.13 to 0.45 ± 0.12 cm) improved in women only. Men showed increased performance in vertical jump power (from 2642 ± 244 to 3134 ± 282 W) and grip strength (from 42.1 ± 5.9 to 48.5 ± 4.9 kg). CONCLUSIONS: A multi-nutrient supplement is effective in improving inflammatory status in both men and women, markers of pain, joint pain, strength, and power in men only, and both anxiety and balance (a risk factor for hip fracture) in women. Therefore, a multi-nutrient supplement may help middle-aged individuals to prolong physical function and maintain a healthy, active lifestyle.

Neuroendocrine-immune interactions and responses to exercise.

This article reviews the interaction between the neuroendocrine and immune systems in response to exercise stress, considering gender differences. The body's response to exercise stress is a system-wide effort coordinated by the integration between the immune and the neuroendocrine systems. Although considered distinct systems, increasing evidence supports the close communication between them. Like any stressor, the body's response to exercise triggers a systematic series of neuroendocrine and immune events directed at bringing the system back to a state of homeostasis. Physical exercise presents a unique physiological stress where the neuroendocrine and immune systems contribute to accommodating the increase in physiological demands. These systems of the body also adapt to chronic overload, or exercise training. Such adaptations alleviate the magnitude of subsequent stress or minimize the exercise challenge to within homeostatic limits. This adaptive capacity of collaborating systems resembles the acquired, or adaptive, branch of the immune system, characterized by the memory capacity of the cells involved. Specific to the adaptive immune response, once a specific antigen is encountered, memory cells, or lymphocytes, mount a response that reduces the magnitude of the immune response to subsequent encounters of the same stress. In each case, the endocrine response to physical exercise and the adaptive branch of the immune system share the ability to adapt to a stressful encounter. Moreover, each of these systemic responses to stress is influenced by gender. In both the neuroendocrine responses to exercise and the adaptive (B lymphocyte) immune response, gender differences have been attributed to the 'protective' effects of estrogens. Thus, this review will create a paradigm to explain the neuroendocrine communication with leukocytes during exercise by reviewing (i) endocrine and immune interactions; (ii) endocrine and immune systems response to physiological stress; and (iii) gender differences (and the role of estrogen) in both endocrine response to physiological stress and adaptive immune response.

Glucocorticoid receptor expression on human B cells in response to acute heavy resistance exercise.

OBJECTIVE: To examine glucocorticoid receptor (GCR) expression on B lymphocytes in response to an acute bout of resistance exercise. METHODS: Using a within-subject design, resistance-trained women (n = 7; age: 22.13 ± 3.09 years; height: 1.69 ± 0.084 m; body weight: 65.60 ± 10.01 kg; body mass index: 22.63 ± 2.03 kg/m²; means ± SD) and men (n = 8; age: 23.28 ± 4.26 years; height: 1.73 ± 0.086 m; body weight: 73.93 ± 12.71 kg; body mass index: 24.51 ± 2.61 kg/m²; means ± SD) performed an acute resistance exercise protocol (6 sets of 5 repetition maximum heavy squats) and a control test in a balanced, randomized order. Blood samples were obtained before, during, and immediately after exercise, and after 1, 6, and 24 h of recovery. GCR expression on circulating B lymphocytes was evaluated with flow cytometry, and circulating cortisol was assayed. RESULTS: Resting GCR expression on B lymphocytes was similar between men and women. GCR expression was elevated in anticipation of exercise (p = 0.047), decreased during exercise (p = 0.049), and increased during recovery (p = 0.05 and p = 0.03 after 1 and 6 h of recovery, respectively). Trends for gender differences were apparent before and during exercise, and after 6 h of recovery. Men had significantly higher cortisol responses during (p = 0.002) and after exercise (p = 0.094) compared to before exercise. In women, however, circulating cortisol concentrations did not significantly increase in response to the squat exercise protocol. CONCLUSIONS: GCR expression on B lymphocytes decreased during resistance exercise and increased during recovery. Circulating cortisol increased during exercise in men only. Responses were attenuated in women compared to men. Our data provide insights into the temporal interactions between the endocrine and immune systems in response to acute heavy resistance exercise in men and women.

Does Cryotherapy Improve Outcomes With Soft Tissue Injury?

REFERENCE: Bleakley C, McDonough S, MacAuley D. The use of ice in the treatment of acute soft-tissue injury: a systematic review of randomized controlled trials. Am J Sport Med. 2004; 32:251-261. CLINICAL QUESTION: What is the clinical evidence base for cryotherapy use? DATA SOURCES: Studies were identified by using a computer-based literature search on a total of 8 databases: MEDLINE, Proquest, ISI Web of Science, Cumulative Index to Nursing and Allied Health (CINAHL) on Ovid, Allied and Complementary Medicine Database (AMED) on Ovid, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effectiveness, and Cochrane Controlled Trials Register (Central). This was supplemented with citation tracking of relevant primary and review articles. Search terms included surgery,orthopaedics,sports injury,soft tissue injury,sprains and strains,contusions,athletic injury,acute,compression, cryotherapy,ice,RICE, andcold. STUDY SELECTION: To be included in the review, each study had to fulfill the following conditions: be a randomized, controlled trial of human subjects; be published in English as a full paper; include patients recovering from acute soft tissue or orthopaedic surgical interventions who received cryotherapy in inpatient, outpatient, or home-based treatment, in isolation or in combination with placebo or other therapies; provide comparisons with no treatment, placebo, a different mode or protocol of cryotherapy, or other physiotherapeutic interventions; and have outcome measures that included function (subjective or objective), pain, swelling, or range of motion. DATA EXTRACTION: The study population, interventions, outcomes, follow-up, and reported results of the assessed trials were extracted and tabulated. The primary outcome measures were pain, swelling, and range of motion. Only 2 groups reported adequate data for return to normal function. All eligible articles were rated for methodologic quality using the PEDro scale. The PEDro scale is a checklist that examines the believability (internal validity) and the interpretability of trial quality. The 11-item checklist yields a maximum score of 10 if all criteria are satisfied. The intraclass correlation coefficient and kappa values are similar to those reported for 3 other frequently used quality scales (Chalmers Scale, Jadad Scale, and Maastricht List). Two reviewers graded the articles, a method that has been reported to be more reliable than one evaluator. MAIN RESULTS: Specific search criteria identified 55 articles for review, of which 22 were eligible randomized, controlled clinical trials. The articles' scores on the PEDro scale were low, ranging from 1 to 5, with an average score of 3.4. Five studies provided adequate information on the subjects' baseline data, and only 3 studies concealed allocation during subject recruitment. No studies blinded their therapist's administration of therapy, and just 1 study blinded subjects. Only 1 study included an intention-to-treat analysis. The average number of subjects in the studies was 66.7; however, only 1 group undertook a power analysis. The types of injuries varied widely (eg, acute or surgical). No authors investigated subjects with muscle contusions or strains, and only 5 groups studied subjects with acute ligament sprains. The remaining 17 groups examined patients recovering from operative procedures (anterior cruciate ligament repair, knee arthroscopy, lateral retinacular release, total knee and hip arthroplasties, and carpal tunnel release). Additionally, the mode of cryotherapy varied widely, as did the duration and frequency of cryotherapy application. The time period when cryotherapy was applied after injury ranged from immediately after injury to 1 to 3 days postinjury. Adequate information on the actual surface temperature of the cooling device was not provided in the selected studies. Most authors recorded outcome variables over short periods (1 week), with the longest reporting follow-ups of pain, swelling, and range of motion recorded at 4 weeks postinjury. Data in that study were insufficient to calculate effect size. Nine studies did not provide data of the key outcome measures, so individual study effect estimates could not be calculated. A total of 12 treatment comparisons were made. Ice submersion with simultaneous exercises was significantly more effective than heat and contrast therapy plus simultaneous exercises at reducing swelling. Ice was reported to be no different from ice and low-frequency or high-frequency electric stimulation in effect on swelling, pain, and range of motion. Ice alone seemed to be more effective than applying no form of cryotherapy after minor knee surgery in terms of pain, but no differences were reported for range of motion and girth. Continuous cryotherapy was associated with a significantly greater decrease in pain and wrist circumference after surgery than intermittent cryotherapy. Evidence was marginal that a single simultaneous treatment with ice and compression is no more effective than no cryotherapy after an ankle sprain. The authors reported ice to be no more effective than rehabilitation only with regard to pain, swelling, and range of motion. Ice and compression seemed to be significantly more effective than ice alone in terms of decreasing pain. Additionally, ice, compression, and a placebo injection reduced pain more than a placebo injection alone. Lastly, in 8 studies, there seemed to be little difference in the effectiveness of ice and compression compared with compression alone. Only 2 of the 8 groups reported significant differences in favor of ice and compression. CONCLUSIONS: Based on the available evidence, cryotherapy seems to be effective in decreasing pain. In comparison with other rehabilitation techniques, the efficacy of cryotherapy has been questioned. The exact effect of cryotherapy on more frequently treated acute injuries (eg, muscle strains and contusions) has not been fully elucidated. Additionally, the low methodologic quality of the available evidence is of concern. Many more high-quality studies are required to create evidence-based guidelines on the use of cryotherapy. These must focus on developing modes, durations, and frequencies of ice application that will optimize outcomes after injury.

The relationship between participation restrictions and selected clinical measures following anterior cruciate ligament reconstruction.

This study examined the relationship between participation restrictions in activities of daily living and sports following anterior cruciate ligament reconstruction (ACLR) and the status of knee structures, performance-based activity limitations, and impairments. Fifty subjects (36 men, 14 women, age=20.6 +/- 1.3 years) at a mean of 31.0 +/- 16.3 months following ACLR participated in this study. Participation restrictions in activities of daily living and sports were measured by the combined scores of the Knee Outcome Survey Activities of Daily Living Scale and Sports Activity Scale. The status of knee structures was assessed by determining the number of previously injured structures in the knee and the time from the most recent ACLR to testing. Performance-based activity limitations were assessed with the single leg hop for distance test. Impairments included isokinetic quadriceps function and anterior tibiofemoral joint laxity. Forward stepwise regression analysis revealed that while the number of injured knee structures alone accounted for 47% of the variability in patient-reported participation restrictions, the combination of the number of injured knee structures, time from ACLR, and the hop index provided the most effective estimate of participation restrictions. Isokinetic quadriceps function and KT-1000 side-to-side differences were not entered into the regression model and were not significant predictors of participation restrictions. We recommend that clinicians use caution in assuming that isokinetic quadriceps function and anterior tibiofemoral joint laxity provide an effective estimate of participation restrictions.