Myocardial Adaptations to Competitive Swim Training.

PURPOSE: Swim training is performed in the prone or supine position and obligates water immersion, factors that may augment cardiac volume loading more than other endurance sports. At present, prospective data defining the cardiac responses to swim training are lacking. We therefore studied myocardial adaptations among competitive swimmers to establish a causal relationship between swim training and left ventricular (LV) remodeling. METHODS: Collegiate swimmers were studied before and after a 90-d period of training intensification. Transthoracic echocardiography was used to examine LV structural and functional adaptations under resting conditions and during an acute LV afterload challenge generated by isometric handgrip testing (IHGT). A sedentary control population was identically studied with IHGT. RESULTS: In response to a discrete period of swim training intensification, athletes (n = 17, 47% female, 19 ± 0.4 yr old) experienced eccentric LV remodeling, characterized by proportionally more chamber dilation than wall thickening, with attendant enhancements of resting LV systolic (LV twist) and diastolic (early and late phase tissue velocities) function. Compared with baseline and controls, athletes posttraining demonstrated greater systolic twist impairment during IHGT. However, training-induced LV dilation coupled with gains in diastolic function offsets this acquired systolic susceptibility to acute afterload, resulting in the relative preservation of stroke volume during IHGT. CONCLUSION: Swim training, a sport characterized by unique cardiac loading conditions, stimulates eccentric LV remodeling with the concomitant augmentation of systolic twist and diastolic relaxation. This volume-mediated cardiac remodeling appears to result in greater systolic susceptibility to acute afterload challenge. Further work is required to establish how training-induced changes in function translate to human performance and whether these are accompanied by physiologic trade-offs with relevance to common forms of heart disease.

Blood Pressure and LV Remodeling Among American-Style Football Players.

OBJECTIVES: This study sought to determine the relationships among American-style football (ASF) participation, acquired left ventricular (LV) hypertrophy, and LV systolic function as assessed using contemporary echocardiographic parameters. BACKGROUND: Participation in ASF has been associated with development of hypertension and LV hypertrophy. To what degree these processes impact LV function is unknown. METHODS: This was a prospective, longitudinal cohort study evaluating National Collegiate Athletic Association Division I football athletes stratified by field position (linemen: n = 30; vs. nonlinemen, n = 57) before and after a single competitive season, using transthoracic echocardiography. LV systolic function was measured using complementary parameters of global longitudinal strain (GLS) (using 2-dimensional speckle-tracking) and ejection fraction (EF) (2-dimensional biplane). RESULTS: ASF participation was associated with field position-specific increases in systolic blood pressure (SBP) (a Δ SBP of 10 ± 8 mm Hg in linemen vs. a Δ SBP of 3 ± 7 mm Hg in nonlinemen; p < 0.001) and an overall increase in incident LV hypertrophy (pre-season = 8% vs. post-season = 25%, p < 0.05). Linemen who developed LV hypertrophy had concentric geometry (9 of 11 [82%]) with decreased GLS (Δ = -1.1%; p < 0.001), whereas nonlinemen demonstrated eccentric LV hypertrophy (8 of 10 [80%]) with increased GLS (Δ = +1.4%; p < 0.001). In contrast, LV ejection fraction in the total cohort, stratified by field position, was not significantly affected by ASF participation. Among the total cohort, lineman field position, post-season weight, SBP, average LV wall thickness, and relative wall thickness were all independent predictors of post-season GLS. CONCLUSIONS: ASF participation at a lineman field position may lead to a form of sport-related myocardial remodeling that is pathologic rather than adaptive. Future study will be required to determine if targeted efforts to control blood pressure, minimize weight gain, and to include an element of aerobic conditioning in this subset of athletes may attenuate this process and translate into tangible downstream health benefits.

Cardiovascular Risk and Disease Among Masters Endurance Athletes: Insights from the Boston MASTER (Masters Athletes Survey To Evaluate Risk) Initiative.

BACKGROUND: Masters athletes (MAs), people over the age of 35 that participate in competitive sports, are a rapidly growing population that may be uniquely at risk for cardiovascular (CV) disease. The objective of this study was to develop a comprehensive clinical CV profile of MA. METHODS: An electronic Internet-based survey (survey response rate = 66 %) was used to characterize a community cohort of MAs residing in Eastern Massachusetts, USA. Clinical and lifestyle factors associated with prevalent CV disease were determined using logistic regression. RESULTS: Among 591 MAs (66 % men, age = 50 ± 9 years) with 21.3 ± 5.5 years of competitive endurance sport exposure, at least one CV risk factor was present in 64 % including the following: family history of premature atherosclerosis (32 %), prior/current tobacco exposure (23 %), hypertension (12.0 %), and dyslipidemia (7.4 %). There was a 9 % (54/591) prevalence of established CV disease which was accounted for largely by atrial fibrillation (AF) and coronary atherosclerosis (CAD). Prevalent AF was associated with years of exercise exposure [adjusted odds ratio, OR (95 % confidence intervals); OR = 1.10 (1.06, 1.21)] and hypertension [OR = 1.05 (1.01, 1.10)] while CAD was associated with dyslipidemia [OR = 9.09 (2.40, 34.39)] and tobacco use [OR = 1.78 (1.34, 3.10)] but was independent of exercise exposure. CONCLUSIONS: Among MAs, AF is associated with prior exercise exposure whereas CAD is associated with typical risk factors including dyslipidemia and prior tobacco use. These findings suggest that there are numerous opportunities to improve disease prevention and clinical care in this population.

Exercise-Induced Left Ventricular Remodeling Among Competitive Athletes: A Phasic Phenomenon.

BACKGROUND: Contemporary understanding of exercise-induced cardiac remodeling is based on cross-sectional data and relatively short duration longitudinal studies. Temporal progression of exercise-induced cardiac remodeling remains incompletely understood. METHODS AND RESULTS: A longitudinal repeated-measures study design using 2-dimensional and speckle-tracking echocardiography was used to examine acute augmentation phase (AAP; 90 days) and more extended chronic maintenance phase (39 months) left ventricular (LV) structural and functional adaptations to endurance exercise training among competitive male rowers (n=12; age 18.6±0.5 years). LV mass was within normal limits at baseline (93±9 g/m(2)), increased after AAP (105±7 g/m(2); P=0.001), and further increased after chronic maintenance phase (113±10 g/m(2); P<0.001 for comparison to post-AAP). AAP LV hypertrophy was driven by LV dilation (ΔLV end-diastolic volume, 9±3 mL/m(2); P=0.004) with stable LV wall thickness (ΔLV wall thickness, 0.3±0.1 mm; P=0.63). In contrast, chronic maintenance phase LV hypertrophy was attributable to LV wall thickening (Δ LV wall thickness, 1.1±0.4 mm; P=0.004) with stable LV chamber volumes (ΔLV end-diastolic volume, 1±1 mL/m(2); P=0.48). Early diastolic peak tissue velocity increased during AAP (-11.7±1.9 versus -13.6±1.3 cm/s; P<0.001) and remained similarly increased after chronic maintenance phase. CONCLUSIONS: In a small sample of competitive endurance athletes, exercise-induced cardiac remodeling follows a phasic response with increases in LV chamber size, early diastolic function, and systolic twist in an acute augmentation phase of exercise training. This is followed by a chronic phase of adaptation characterized by increasing wall thickness and regression in LV twist. Training duration is a determinant of exercise-induced cardiac remodeling and has implications for the assessment of myocardial structure and function in athletes.

Endurance Exercise-Induced Cardiac Remodeling: Not All Sports Are Created Equal.

BACKGROUND: The term endurance sport (ES) is broadly used to characterize any exercise that requires maintenance of high cardiac output over extended time. However, the relative amount of isotonic (volume) versus isometric (pressure) cardiac stress varies across ES disciplines. To what degree ES-mediated cardiac remodeling varies, as a function of superimposed isometric stress, is uncertain. The aim of this study was to compare the cardiac remodeling characteristics associated with two common yet physiologically distinct forms of ES. METHODS: Healthy competitive male long-distance runners (high isotonic, low isometric stress; n = 40) and rowers (high isotonic, high isometric stress; n = 40) were comparatively studied after 3 months of sport-specific exercise training with conventional and speckle-tracking two-dimensional echocardiography. RESULTS: Rowers demonstrated dilated left ventricular (LV) volumes and elevated LV mass (i.e., eccentric LV hypertrophy), whereas runners demonstrated normal LV mass (runners, 88 ± 11 g/m(2); rowers, 108 ± 13 g/m(2); P < .001) despite comparatively larger LV volumes (runners, 101 ± 10 mL/m(2); rowers, 89 ± 13 mL/m(2); P < .001) consistent with eccentric LV remodeling. Increasing LV mass was associated with increased reliance on early diastolic filling (LV mass vs E'/A' ratio, R = 0.47, P < .001) indicating "mass-dependent" diastolic function. Right ventricular dilation of similar magnitude and LV systolic function, as assessed by numerous complementary indices, were similar in both groups. CONCLUSIONS: Cardiac adaptations differ significantly as a function of ES discipline. Further work is required to determine the mechanisms for this differential adaptation, to develop definitive ES discipline-specific normative values, and to evaluate the optimal therapeutic use of specific ES disciplines among patients with common cardiovascular diseases.

Ruptured Tendons in Anabolic-Androgenic Steroid Users: A Cross-Sectional Cohort Study.

BACKGROUND: Accumulating case reports have described tendon rupture in men who use anabolic-androgenic steroids (AAS). However, no controlled study has assessed the history of tendon rupture in a large cohort of AAS users and comparison nonusers. HYPOTHESIS: Men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture compared with non-AAS-using bodybuilders. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Medical histories were obtained from 142 experienced male bodybuilders aged 35 to 55 years recruited in the course of 2 studies. Of these men, 88 reported at least 2 years of cumulative lifetime AAS use, and 54 reported no history of AAS use. In men reporting a history of tendon rupture, the circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use (if applicable) were recorded. Surgical records were obtained for most participants. RESULTS: Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers, reported at least 1 lifetime tendon rupture. The hazard ratio for a first ruptured tendon in AAS users versus nonusers was 9.0 (95% CI, 2.5-32.3; P < .001). Several men reported 2 or more independent lifetime tendon ruptures. Interestingly, upper-body tendon ruptures occurred exclusively in the AAS group (15 [17%] AAS users vs 0 nonusers; risk difference, 0.17 [95% CI, 0.09-0.25]; P < .001 [hazard ratio not estimable]), whereas there was no significant difference between users and nonusers in risk for lower-body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio, 3.1 [95% CI, 0.7-13.8]; P = .13). Of 31 individual tendon ruptures assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically, with complete or near-complete ultimate restoration of function. CONCLUSION: AAS abusers, compared with otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper-body tendon rupture.

Myocardial adaptations to recreational marathon training among middle-aged men.

BACKGROUND: Myocardial adaptations to exercise have been well documented among competitive athletes. To what degree cardiac remodeling occurs among recreational exercisers is unknown. We sought to evaluate the effect of recreational marathon training on myocardial structure and function comprehensively. METHODS AND RESULTS: Male runners (n=45; age, 48±7 years; 64% with ≥1 cardiovascular risk factor) participated in a structured marathon-training program. Echocardiography, cardiopulmonary exercise testing, and laboratory evaluation were performed pre and post training to quantify changes in myocardial structure and function, cardiorespiratory fitness, and traditional cardiac risk parameters. Completion of an 18-week running program (25±9 miles/wk) led to increased cardiorespiratory fitness (peak oxygen consumption, 44.6±5.2 versus 46.3±5.4 mL/kg per minute; P<0.001). In this setting, there was a significant structural cardiac remodeling characterized by dilation of the left ventricle (end-diastolic volume, 156±26 versus 172±28 mL, P<0.001), right ventricle (end-diastolic area=27.0±4.8 versus 28.6±4.3 cm(2); P=0.02), and left atrium (end-diastolic volume, 65±19 versus 72±19; P=0.02). Functional adaptations included increases in both early (E'=12.4±2.5 versus 13.2±2.0 cm/s; P=0.007) and late (A'=11.5±1.9 versus 12.2±2.1 cm/s; P=0.02) left ventricular diastolic velocities. Myocardial remodeling was accompanied by beneficial changes in cardiovascular risk factors, including body mass index (27.0±2.7 versus 26.7±2.6 kg/m(2); P<0.001), total cholesterol (199±33 versus 192±29 mg/dL; P=0.01), low-density lipoprotein (120±29 versus 114±26 mg/dL; P=0.01), and triglycerides (100±52 versus 85±36 mg/dL; P=0.02). CONCLUSIONS: Among middle-aged men, recreational marathon training is associated with biventricular dilation, enhanced left ventricular diastolic function, and favorable changes in nonmyocardial determinants of cardiovascular risk. Recreational marathon training may, therefore, serve as an effective strategy for decreasing incident cardiovascular disease.

Prolonged hypogonadism in males following withdrawal from anabolic-androgenic steroids: an under-recognized problem.

AIMS: To assess the frequency and severity of hypogonadal symptoms in male long-term anabolic-androgenic steroid (AAS) misusers who have discontinued AAS use. DESIGN: Cross-sectional, naturalistic. SETTING: Out-patient facility. PARTICIPANTS: Twenty-four male former long-term AAS users and 36 non-AAS-using weightlifters, recruited by advertisement in Massachusetts, USA. Five of the former users were currently receiving treatment with physiological testosterone replacement, leaving 19 untreated users for the numerical comparisons below. MEASUREMENTS: The Structured Clinical Interview for DSM-IV, questions regarding history of AAS use, physical examination, serum hormone determinations and the International Index of Erectile Function (IIEF). FINDINGS: Compared with the 36 non-AAS-using weightlifters, the 19 untreated former AAS users displayed significantly smaller testicular volumes [estimated difference, 95% confidence interval (CI) = 2.3 (0.1, 4.5) ml; P = 0.042] and lower serum testosterone levels [estimated difference: 95% CI = 131 (25, 227) dl; P = 0.009], with five users showing testosterone levels below 200 ng/dl despite abstinence from AAS for 3-26 months. Untreated former users also displayed significantly lower scores on the IIEF sexual desire subscale [estimated difference: 95% CI = 2.4 (1.3, 3.4) points on a 10-point scale; P < 0.001]. In the overall group of 24 treated plus untreated former users, seven (29%) had experienced major depressive episodes during AAS withdrawal; four of these had not experienced major depressive episodes at any other time. Two men (8%) had failed to regain normal libidinal or erectile function despite adequate replacement testosterone treatment. CONCLUSIONS: Among long-term anabolic-androgenic steroid misusers, anabolic-androgenic steroid-withdrawal hypogonadism appears to be common, frequently prolonged and associated with substantial morbidity.

ECG findings in competitive rowers: normative data and the prevalence of abnormalities using contemporary screening recommendations.

BACKGROUND/AIM: The international governing body for competitive rowing recently mandated the inclusion of 12-lead ECG during preparticipation screening. We therefore sought to describe normative ECG characteristics and to examine the prevalence of abnormal ECG findings as defined by contemporary athlete ECG interpretation criteria among competitive rowers. METHODS: Competitive rowers (n=330, 56% male) underwent standard 12-lead ECG at the time of collegiate preparticipation screening. ECGs were analysed quantitatively to develop a sport-specific normative database and then for the presence of abnormalities in accordance with the 2010 European Society of Cardiology (ESC) recommendations and 2013 'Seattle Criteria.' RESULTS: 94% of rowers had one or more training-related ECG patterns including sinus bradycardia (51%), sinus arrhythmia (55%), and incomplete right bundle branch block (42%). Males were more likely than females to have isolated voltage criteria for left ventricular hypertrophy (LVH) (51% vs 8%, p<0.001) and early repolarisation pattern (76% vs 23%, p<0.001). Application of the 2010 ESC criteria, compared to the Seattle criteria, resulted in the classification of a significantly greater number of abnormal ECGs (47% vs 4%; p<0.001). The detection of true pathology, accomplished by both interpretation criteria, was confined to a single case of ventricular pre-excitation. CONCLUSIONS: Training-related ECG patterns with several gender-based differences are common among competitive rowers. The diagnostic accuracy and down-stream clinical implications of ECG-inclusive preparticipation screening among rowers will be dictated by the choice and future refinement of ECG interpretation criteria.

A meta-analysis of the efficacy of laser phototherapy on pain relief.

OBJECTIVE: Laser phototherapy has been widely used to relieve pain for more than 30 years, but its efficacy remains controversial. To ascertain the overall effect of phototherapy on pain, we aggregated the literature and subjected the studies to statistical meta-analysis. METHODS: Relevant original studies were gathered from every available source and coded. Articles that met preestablished inclusion criteria were subjected to statistical meta-analysis, using Cohen's d statistic to determine treatment effect sizes. RESULTS: Fifty-two effect sizes were computed from the 22 articles that met the inclusion criteria. The resulting overall mean effect size was highly significant; d = +0.84 (95% confidence interval = 0.44-1.23). The effect size remained significant even when a high outlying d value was conservatively excluded from the analysis; d = +0.66 (95% confidence interval = 0.46-0.86). The fail-safe number associated with the overall treatment effect, that is, the number of additional studies in which phototherapy has negative or no effect on pain needed to negate the overall large effect size of +0.84, was 348. DISCUSSION: These findings warrant the conclusion that laser phototherapy effectively relieves pain of various etiologies; making it a valuable addition to contemporary pain management armamentarium.

A meta-analysis of the efficacy of phototherapy in tissue repair.

OBJECTIVE: The effect of phototherapy on tissue repair was determined by aggregating the literature and using statistical meta-analysis to analyze pertinent studies published between 2000 and 2007. BACKGROUND DATA: Phototherapy has been used for more than 40 y; however, its efficacy on tissue repair remains contentious. METHOD: Related original studies were gathered from every available source. The papers were then screened and coded; those meeting pre-established inclusion criterion were subjected to meta-analysis, using Cohen's d statistic to determine treatment effect size. RESULTS: Seventy effect sizes were computed from the 23 papers that met the inclusion criteria. The overall mean effect obtained was highly significant, d = +1.94 (95% confidence interval = 0.58-2.50). Further analyses revealed a similarly positive effect of phototherapy on tissue repair in experimental animal studies, d = +2.60, and a small to moderately positive effect in human cases of tissue repair, d = +0.34. The fail-safe number associated with the overall effect was 869; i.e., the number of additional studies in which phototherapy has negative or no effect on wound healing needed to negate the overall large effect size of + 1.94. The corresponding fail-safe numbers for experimental animal and human tissue repair studies were 612 and 64, respectively. CONCLUSION: These findings indicate that phototherapy is a highly effective form of treatment for tissue repair, with stronger supporting evidence resulting from experimental animal studies than human studies.