Effects of endurance exercise training on left ventricular structure in healthy adults: a systematic review and meta-analysis.

AIMS: To determine the impact of endurance training (ET) interventions on left ventricular (LV) chamber size, wall thickness, and mass in healthy adults. METHODS AND RESULTS: Electronic databases including CINAHL, MEDLINE, PsycINFO, SPORTDiscus, Cochrane library, and EBM Reviews were searched up to 4 January 2022. Criteria for inclusion were healthy females and/or males (>18 years), ET intervention for ≥2 weeks, and studies reporting pre- and post-training LV structural parameters. A random-effects meta-analysis with heterogeneity, publication bias, and sensitivity analysis was used to determine the effects of ET on LV mass (LVM) and diastolic measures of interventricular septum thickness (IVSd), posterior wall thickness (PWTd), and LV diameter (LVDd). Meta-regression was performed on mediating factors (age, sex, training protocols) to assess their effects on LV structure. Eighty-two studies met inclusion criteria (n = 1908; 19-82 years, 33% female). There was a significant increase in LVM, PWTd, IVSd, and LVDd following ET [standardized mean difference (SMD) = 0.444, 95% confidence interval (CI): 0.361, 0.527; P < 0.001; SMD = 0.234, 95% CI: 0.159, 0.309; P < 0.001; SMD = 0.237, 95% CI: 0.159, 0.316; P < 0.001; SMD = 0.249, 95% CI:0.173, 0.324; P < 0.001, respectively]. Trained status, training type, and age were the only mediating factors for change in LVM, where previously trained, mixed-type training, young (18-35 years), and middle-aged (36-55 years) individuals had the greatest change compared with untrained, interval-type training, and older individuals (>55 years). A significant increase in wall thickness was observed in males, with a similar augmentation of LVDd in males and females. Trained individuals elicited an increase in all LV structures and ET involving mixed-type training and rowing and swimming modalities conferred the greatest increase in PWTd and LVDd. CONCLUSION: Left ventricular structure is significantly increased following ET. Males, young and trained individuals, and ET interventions involving mixed training regimes elicit the greatest changes in LV structure.

Heart structure significantly increases the following endurance training (ET) ≥2 weeks.Changes in heart structure were most prominent in males, who are young (18­35 years), already trained, and following concurrent continuous and interval training.Changes in heart size were not shown in older individuals (>55 years) compared with young and middle-aged individuals.While both males and females similarly increase their cavity size and heart mass, sex differences were revealed for wall thickness where significant increases were seen in males but not females.

Sleep Quality and Sleep Behaviors in Varsity Athletes: A Pilot Study.

Sleep hygiene practices may hinder university athletes from obtaining quality sleep to support health and performance. We sought to provide a comprehensive evaluation of sleep quality and behaviors in varsity athletes using validated sleep questionnaires: the Athlete Sleep Screening Questionnaire (ASSQ) and the Athlete Sleep Behavior Questionnaire (ASBQ). Sixty-four (n = 64) athletes participated (54% female; 71% Caucasian). The mean age was 20.3 ± 1.7 years and the mean BMI was 23.3 ± 3.3. Fifty-one percent met the threshold for adequate sleep (7+ h) and 54% reported being somewhat/very satisfied with sleep quality. Global scores for ASSQ Sleep Difficulty and ASBQ sleep behaviors were significantly correlated (r = 0.31; p = 0.014) and not significantly different across age, academic year, or residence. According to the ASSQ, 11% and 24% were classified as having severe or moderate sleep problems, respectively. The ASBQ categorized 62% as having "poor" sleep behaviors. Notable sleep-influencing factors included a high frequency of emotional/cognitive processing of sport-performance issues (46.9%), frequent use of light-emitting devices before bed (90%), training after 7 pm (65%), and the use of sleep medication (19%). Half of the university athletes did not meet the thresholds for adequate sleep, and some may require a referral for clinical sleep issues. The majority of these athletes' sleep behaviors do not promote adequate sleep. The ASSQ shows utility to assess gradations in clinical sleep difficulty; the ASBQ could be used in concert with the ASSQ to discern "cognitive and physiological arousal" targets for use in educational workshops designed to promote optimal sleep hygiene in university athletes.