Whole body cryotherapy and recovery from exercise induced muscle damage: A systematic review

Introduction Cold therapies are used regularly in medicine for their analgesic and anti-inflammatory effects. Whole-body cryotherapy (WBC) involves exposure to air maintained between -110 and -160oC, and is hypothesised to reduce pain, local and systemic inflammation. WBC has recently become popular in an exercise and sporting context as a recovery method after skeletal muscle damage, however, research examining the efficacy of WBC in an athletic context is minimal. This review seeks to summarise the evidence for the effects of WBC on exercise recovery measures. Methods Electronic database searches were conducted from March to April 2013. Six large online databases were used; MEDLINE, SPORTDiscus, Scopus, Web of Science, PubMed and AMED. The search targeted human studies with an exercise task, and WBC intervention. Results included randomised controlled trials (RCT’s), uncontrolled trials and crossover designs. Results A total of 8 studies were included in the review. Two RCT’s, four crossover trials and two uncontrolled trials were identified. Five studies showed WBC had no effect on markers of muscle damage or inflammation post exercise, while 3 studies show a positive effect. Three out of the eight studies measured maximal muscle force production and subjective pain levels following exercise and WBC, with two showing WBC had a positive effect on muscle force recovery and pain. A meta-analysis was not conducted due to the heterogeneity of the studies. Conclusion The current evidence for the efficacy of WBC on exercise recovery is unclear. Published studies report mixed findings, and the study designs make these results difficult to interpret. As WBC is proposed as an aid to recovery in an athletic population, repeated measures of performance, muscle force production and pain are of importance to the athlete, however, are minimally reported in the literature. Cold water immersion (CWI) is widely used in an athletic setting for recovery, and has much literature supporting its use for the reduction of pain post-exercise. Well-designed RCT’s with controlled exercise interventions targeting performance measures are needed, in particular comparison of WBC with CWI data is needed for evaluation

Effects of whole body cryotherapy and cold water immersion on immune and inflammatory markers following exercise induced muscle damage

Introduction: Cold therapies are used regularly in medicine for their analgesic and anti-inflammatory effects. Whole-body cryotherapy (WBC) involves exposure to air maintained between -110 and -160oC, and is hypothesised to reduce pain, local and systemic inflammation. WBC has recently become popular in an exercise and sporting context as a recovery method after skeletal muscle damage. However, research examining the efficacy of WBC in an athletic context is minimal, in particular, studies comparing WBC to currently accepted recovery methods are lacking. Cold water immersion (CWI) is a widely researched and applied method of skeletal muscle recovery in sport science. As yet, no study has compared the proposed new method of WBC and the currently practiced method of CWI. We have designed a randomised control trial to examine the efficacy of WBC, as compared with CWI on recovery from a bout of eccentric muscle damage. Methods: Sixty healthy male subjects will perform skeletal muscle function tests and an eccentric muscle damage protocol of their left quadriceps femoris, using an isokinetic dynamometer. They will then be randomly assigned to one of 3 groups, WBC, CWI or a passive recovery control (PAS). The WBC will expose subjects to -160°C for 3min, using cold air. The CWI condition involves whole body exposure for 3min, in water maintained at 12°C. The PAS will have subjects seated comfortably at room temperature following the exercise protocol. Blood samples, muscle functional measurements and pain reports will be taken before muscle damage, immediately following damage, prior to therapy administration and post therapy. Further follow up measures to be taken 6 h post, 24 h and 7 days post. Blood samples will be analysed for changes in interleukins 6, 8 and 10, creatine kinase and leukocyte population kinetics. Results: Testing is being conducted. Results to be presented at the international society of exercise immunology (ISEI) symposium in September 2013

Reproducibility of creatine kinase: how useful is this measurement tool?

Establishing the reproducibility of a measurement is essential for repeated testing to ensure that any systematic change is a result of an external influence (i.e. intervention), as oppossed to normal random variation. Although some degree of error is inherent in any measure, a measurement tool should yield consistent results that do not fluctuate to an unacceptable degree from one test to another. Creatine kinase (CK) is consistently measured in the blood as a marker of exercise induced muscle damage (EIMD). However, its usefulness as a predictive tool to examine the temporal pattern, and magnitude of muscle damage has been questioned. PURPOSE:The main aim of the present study was to employ a variety of reproducibility statistics in order to examine the typical level of measurement error for CK. METHODS: Fifty (36 male, 14 female), apparently healthy participants completed three trials on three separate occasions with each trial separated by 48 - 72 h. The initial trial served as a familiarisation. During trials 2 and 3 (48 h), CK measures were obtained using standard fingerprick technique, and analysed in duplicate immediatley using a colorimetric assay procedure. Each participant completed their trials at the same time of day, following identical pre-test procedures. RESULTS: The intra-test coefficient of variation (CV) within our laboratory was 9%. Dependent t-tests indicated there was no systematic bias between trials (p = 0.82). The interdian CV displayed low reproducibility (20%). Furthermore, the 95% limits of agreement (LoA) were -69.7 to 63.5 iµ/L. However, the intraclass correlation coefficient (ICC) was 0.90, which can be clasified as displaying ‘high’ reproducibility. CONCLUSION: The interdian CV demonstrates that under identical resting conditions (48 h apart), CK displays inherent low absoulte reproducibility, which may obscure a true experimental effect. However, interpretation of the ICC, suggests that CK has high relative reproducibility. The high range of observed CK values is thought to have increased the size of the correlation. Subsequently, an indivdual change in CK following EIMD may not be indicative of the magnitude of damage, and may simply be a result of the inherent variation (e.g. biological). Therefore, it is advised that caution should be taken when using CK within experimental research, and as an indication of when an athlete has recovered, and is able to recommence training

The cytokine response to a 30 min downhill run

ISEI Abstract – 7 The cytokine response to a 30 min downhill run L TAYLOR1, CHRISMAS BCR1, CARROLL S2, SMITH A3, PEMBERTON P3, SIEGLER JC4 and MIDGLEY AW5. 1 Applied Sport and Exercise Physiology (ASEP) & Muscle Cellular and Molecular Physiology (MCMP) research groups, Institute of Sport and Physical Activity Research (ISPAR), Department of Sport & Exercise Sciences, University of Bedfordshire, Bedford, UK. 2Department of Sport, Health & Exercise Science, The University of Hull, Hull, UK. 3Department of Clinical Biochemistry, Central Manchester Foundation Trust, Manchester, UK. 4School of Science & Health, University of Western Sydney, Sydney, Australia. 5Department of Sport & Physical Activity, Edge Hill University, Ormskirk, UK. ABSTRACT Eccentric exercise has been ubiquitously shown to result in exericse induced muscle damage (EIMD), accompanied with delayed onset muscle soreness (DOMS). Although eccentric exercise may induce greater neuromuscular adaptation, functional performance may be impaired, and soreness may persist for several days following this type of exercise. This is primarily thought to be due to structural damage to the muscle fibres. In addition to the mechanical theory of EIMD, it has been suggested that an increased inflammatory response may be associated with DOMS. Furthermore, it is possible that the inflammatory response may play a role in mediating recovery, and adaptation following EIMD. However, the effects of EIMD on markers of inflammation have produced inconsistent results. PURPOSE: The main aim of the present study was to investigate the cytokine response to a 30 min downhill run. METHODS: Fifty (36 male, 14 female), apparently healthy participants performed a 30 min downhill run (-12.5%, 70% Vmax). Interleukin 6 (IL-6), high sensitivity C reactive protein (hs-CRP), and tumor necrosis factor alpha (TNF-α) were measured at 1 h, 24 h and 48 h post downhill run. Additionally, isometric maximum voluntary contraction (MVC), and perceived muscle soreness were measured at 24 h and 48 h post downhill run. RESULTS: Detectable levles of TNF-α were only present in three participants, and therefore, these data were excluded from the analysis. There was no significant difference in IL-6 or hs-CRP at any time point (p \u3e 0.10). However, there was a significant decrease in MVC (p ≤ 0.001). On average MVC decreased by 11% and 8% in the dominant and non-dominant leg at 24 h and 48 h respectively. Furthermore, there was a significant increase in muscle soreness (p \u3c 0.001). On average soreness increased by 49 mm and 51 mm 24 h and 48 h post downhill run. CONCLUSION: The significant increase in muscle soreness in the present study is indicative of EIMD. Furthermore, the significant decrement in MVC at 24 h and 48 h post downhill run, demonstrates that neuromuscular function was impaired. The lack of any significant increase in the cytokine response, supports the theory that mechanical damage is the primary mechanism associated with the EIMD and DOMS phenomenon. Nevertheless, when interpreting these results it is important to consider that due to the sampling times employed in the present study, an inflammatory response may have been missed

Exercise tolerance during VO2max testing is a multifactorial psychobiological phenomenon

Fifty-nine men completed a VO2max test and a questionnaire to establish reasons for test termination, perceived exercise reserve (difference between actual test duration and the duration the individual perceived could have been achieved if continued until physical limitation), and perception of verbal encouragement. Participants gave between 1 and 11 factors as reasons for test termination, including leg fatigue, various perceptions of physical discomfort, safety concerns, and achievement of spontaneously set goals. The two most common main reasons were leg fatigue and breathing discomfort, which were predicted by pre-to-post test changes in pulmonary function (p = 0.038) and explosive leg strength (p = 0.042; R2 = 0.40). Median (interquartile range) perceived exercise reserve, was 45 (50) s. Two-thirds of participants viewed verbal encouragement positively, whereas one-third had a neutral or negative perception. This study highlights the complexity of exercise tolerance during VO2max testing and more research should explore these novel findings

Genotype, Childhood Maltreatment, and Their Interaction in the Etiology of Adult Antisocial Behaviors

BACKGROUND: Maltreatment by an adult or caregiver during childhood is a prevalent and important predictor of antisocial behaviors in adulthood. A functional promoter polymorphism in the monoamine oxidase A (MAOA) gene has been implicated as a moderating factor in the relationship between childhood maltreatment and antisocial behaviors. Although there have been numerous attempts at replicating this observation, results remain inconclusive. METHODS: We examined this gene-environment interaction hypothesis in a sample of 3356 white and 960 black men (aged 24-34) participating in the National Longitudinal Study of Adolescent Health. RESULTS: Primary analysis indicated that childhood maltreatment was a significant risk factor for later behaviors that violate rules and the rights of others (p .05). Power analyses indicated that these results were not due to insufficient statistical power. CONCLUSIONS: We could not confirm the hypothesis that MAOA genotype moderates the relationship between childhood maltreatment and adult antisocial behaviors

Depression, Stressful Life Events, and the Impact of Variation in the Serotonin Transporter: Findings from the National Longitudinal Study of Adolescent to Adult Health (Add Health)

BackgroundThe low transcriptionally efficient short-allele of the 5HTTLPR serotonin transporter polymorphism has been implicated to moderate the relationship between the experience of stressful life events (SLEs) and depression. Despite numerous attempts at replicating this observation, results remain inconclusive.MethodsWe examined this relationship in young-adult Non-Hispanic white males and females between the ages of 22 and 26 (n = 4724) participating in the National Longitudinal Study of Adolescent to Adult Health (Add Health) with follow-up information every six years since 1995.ResultsLinear and logistic regression models, corrected for multiple testing, indicated that carriers of one or more of the S-alleles were more sensitive to stress than those with two L-alleles and at a higher risk for depression. This relationship behaved in a dose-response manner such that the risk for depression was greatest among those who reported experiencing higher numbers of SLEs. In post-hoc analyses we were not able to replicate an interaction effect for suicide ideation but did find suggestive evidence that the effects of SLEs and 5HTTLPR on suicide ideation differed for males and females. There were no effects of childhood maltreatment.DiscussionOur results provide partial support for the original hypothesis that 5-HTTLPR genotype interacts with the experience of stressful life events in the etiology of depression during young adulthood. However, even with this large sample, and a carefully constructed a priori analysis plan, the results were still not definitive. For the purposes of replication, characterizing the 5HTTLPR in other large data sets with extensive environmental and depression measures is needed

Population Frequencies of the Triallelic 5HTTLPR in Six Ethnicially Diverse Samples from North America, Southeast Asia, and Africa

Genetic differences between populations are a potentially an important contributor to health disparities around the globe. As differences in gene frequencies influence study design, it is important to have a thorough understanding of the natural variation of the genetic variant(s) of interest. Along these lines, we characterized the variation of the 5HTTLPR and rs25531 polymorphisms in six samples from North America, Southeast Asia, and Africa (Cameroon) that differ in their racial and ethnic composition. Allele and genotype frequencies were determined for 24,066 participants. Results indicated higher frequencies of the rs25531 G-allele among Black and African populations as compared with White, Hispanic and Asian populations. Further, we observed a greater number of ‘extra-long’ (‘XL’) 5HTTLPR alleles than have previously been reported. Extra-long alleles occurred almost entirely among Asian, Black and Non-White Hispanic populations as compared with White and Native American populations where they were completely absent. Lastly, when considered jointly, we observed between sample differences in the genotype frequencies within racial and ethnic populations. Taken together, these data underscore the importance of characterizing the L-G allele to avoid misclassification of participants by genotype and for further studies of the impact XL alleles may have on the transcriptional efficiency of SLC6A4

The Accuracy of the Electrocardiogram during Exercise Stress Test Based on Heart Size

BACKGROUND: Multiple studies have shown that the exercise electrocardiogram (ECG) is less accurate for predicting ischemia, especially in women, and there is additional evidence to suggest that heart size may affect its diagnostic accuracy. HYPOTHESIS: The purpose of this investigation was to assess the diagnostic accuracy of the exercise ECG based on heart size. METHODS: We evaluated 1,011 consecutive patients who were referred for an exercise nuclear stress test. Patients were divided into two groups: small heart size defined as left ventricular end diastolic volume (LVEDV) <65 mL (Group A) and normal heart size defined as LVEDV ≥65 mL (Group B) and associations between ECG outcome (false positive vs. no false positive) and heart size (small vs. normal) were analyzed using the Chi square test for independence, with a Yates continuity correction. LVEDV calculations were performed via a computer-processing algorithm. SPECT myocardial perfusion imaging was used as the gold standard for the presence of coronary artery disease (CAD). RESULTS: Small heart size was found in 142 patients, 123 female and 19 male patients. There was a significant association between ECG outcome and heart size (χ(2) = 4.7, p = 0.03), where smaller hearts were associated with a significantly greater number of false positives. CONCLUSIONS: This study suggests a possible explanation for the poor diagnostic accuracy of exercise stress testing, especially in women, as the overwhelming majority of patients with small heart size were women