• Associations between balance ability and dance performance using field balance tests

      Clarke, Frances; Koutedakis, Yiannis; Wilson, Margaret; Wyon, Matthew (Science & Medicine, 2019-09-01)
      Purpose: Although balance is a key element of dance, it remains to be confirmed which balance components are associated with dance performance. The aim of this study was to assess the associations between different balance field tests and dance performance in an in-house measure in ballet, contemporary and jazz genres. Methods: 83 female undergraduate dance students (20±1.5 years; 163.04±6.59 cm; 60.97±10.76 kg) were subjected to the Star Excursion Balance Test (SEBT), the Airplane test, a dance-specific pirouette test, the modified Romberg test, and the BioSway Balance System (Biodex, USA). The results from these balance tests were compared to the participants’ technique and repertoire performance scores in ballet, contemporary, and jazz genres. Results: Ballet scores were best predicted by SEBT 90˚ and Romberg for technique (r = 0.4, p = 0.001, SEE ±2.49) and Romberg, SEBT 90˚, and SEBT 225˚ for repertoire (r = 0.51, p = 0.001, SEE±1.99). Contemporary data indicated SEBT 90˚ and Romberg for technique (r = 0.37, p = 0.001, SEE±2.67) and SEBT 225˚ for repertoire (r = 0.27, p = 0.015, SEE±2.29). Jazz indicated SEBT 90˚, Romberg, SEBT 315˚, and SEBT 225˚ for technique (r = 0.51, p = 0.001, SEE±2.28) and SEBT 225˚ and Romberg for repertoire (r = 0.41, p = 0.001, SEE±2.29). Conclusion: The present study suggests that balance ability has a limited influence on dance performance, with existing field balance tests demonstrating low to moderate associations with dance technique and repertoire.
    • Balance in theatrical dance performance: a systematic review

      Clarke, Frances; Koutedakis, Yiannis; Wilson, Margaret; Wyon, Matthew (Science & Medicine, 2018-12-01)
      AIM: Due to movement complexity and the use of interdisciplinary styles, all theatrical dance genres require dancers to have excellent balance skills to meet choreographic demands. The aim of this systematic review was to evaluate the experimental evidence for the relationship between balance and dance performance, including balance testing, balance training, and balance performance. The key focus was on balance and theatrical styles of dance, involving adult participants who were either in full-time dance training or professional dancers. METHODS: The databases MEDLINE, PubMed, Cumulative Index to Nursing & Allied Health (CINAHL), SPORTDiscus, Cochrane, ScienceDirect, and Google Scholar were searched using MeSH terms postural balance, balance, postural, musculoskeletal equilibrium, and postural equilibrium, and used in combination with dance, between 1980 and 2016. PRISMA recommendations were applied in modifications to the search terms. RESULTS: The initial search revealed 1,140 published articles. After applying inclusion and exclusion criteria, 47 articles were judged to be relevant for further assessment using the GRADE system. Results revealed only 1 randomized controlled trial (RCT); the remaining articles were experimental without randomisation or pre-experimental, thus achieving low scores. A total of 39 articles focused on balance ability, including postural sway and control; 5 were related to multi-joint coordination; and 3 investigated laterality and balance. Female ballet dancers were the most studied population, while a wide range of measurement tools and balance tasks were employed. CONCLUSION: The available material on balance and dance performance is of rather low quality. There is a need for more RCTs and intervention balance studies.
    • Circulating Sclerostin responses to acute weight and non weight bearing sport activity in pre adolescent males

      Jamurtas, Athanasios Z; Leontsini, Diamanda; Avloniti, Alexandra; Vlachopoulos, Dimitris; Stampoulis, Theodoros; Chatzinikolaou, Athanasios; Gracia-Marco, Luis; Ubago-Guisado, Esther; Makris, Konstantinos; Tournis, Symeon; et al. (Ovid Technologies (Wolters Kluwer Health), 2017-05-01)
      Mechanical loading, i.e. physical activity and/or exercise, promotes bone formation during growth. Sclerostin, a glycoprotein, mediates osteocytes' response to mechanical loading by inhibiting the Wnt/lf-catenin pathway thereby inhibiting bone formation.
    • The effects of pre-exercise corinthian currants supplementation on antioxidant responses

      Jamurtas, Athanasios Z; Deli, Chariklia K; Fatouros, Ioannis G; Selemekou, Maria; Papoutsis, Alexandros; Koutedakis, Yiannis; Karathanos, Vaios (Ovid Technologies (Wolters Kluwer Health), 2016-05)
      Τhe use of nutritional supplements before and during a sporting event, especially of a prolonged nature, is very common among competitors and routinely advised by exercise professionals. Corinthian currants have a high carbohydrate content making them a potentially ideal carbohydrate source for prolonged exercise. However, their effectiveness as an ergogenic aid has never been studied.
    • Thermogenic capacity of human white-fat: the actual picture

      Dinas, Petros C; Krase, Argyro; Nintou, Eleni; Georgakopoulos, Alexandros; Granzotto, Marnie; Metaxas, Marinos; Karachaliou, Eleni; Rossato, Marco; Vettor, Roberto; Georgoulias, Panagiotis; et al. (MDPI AG, 2019-08-29)
      Cold exposure and exercise may increase thermogenic capacity of white adipose tissue (WAT), which could subsequently enhance energy expenditure and body weight loss. We aimed to identify possible alterations in uncoupling protein 1 (UCP1)—the main biomarker of thermogenic activation—in human WAT due to both cold exposure and exercise, as well as the link between environmental temperature and thermogenic capacity of human WAT. MATERIAL & METHOD: We conducted four human experimental studies and two systematic reviews and meta-analyses—PROSPERO registration CRD42019120116, CRD42019120213. RESULTS: UCP1 mRNA was higher in winter than in summer [t(30) = 2.232, p = 0.03] in human WAT and our meta-analysis showed a main effect of cold exposure on human UCP1 mRNA [standard mean difference (Std-md) = 1.81, confidence interval (CI) = 0.50–3.13, p = 0.007]. However, UCP1 mRNA/protein expressions displayed no associations with %fat mass or BMI (p > 0.05, Cohen’s f2 < 0.20). Both a 2-hour cooling and a non-cooling protocol preceding the positron emission tomography/computed tomography (PET/CT) measurements revealed no association between environmental temperature and standardised uptake value (SUVmax) of human WAT, as well as no mean differences in SUVmax-WAT-activity between winter and summer. An 8-week exercise program had no effect on UCP1 of human WAT or on body composition. Our meta-analysis also revealed: (a) no effect of chronic exercise on human UCP1 mRNA, (b) a main effect of chronic exercise on UCP1 protein concentrations (Std-md = 0.59, CI = 0.03–1.16, p = 0.04) and UCP1 mRNA (Std-md = 1.76, CI = 0.48–3.04, p = 0.007) in WAT of normal diet animals, c) a main effect of chronic exercise on UCP1 mRNA (Std-md = 2.94, CI = 0.24–5.65, p = 0.03) and UCP1 protein concentrations (Std-md = 2.06, CI = 0.07–4.05, p = 0.04) of high-fat diet animals. CONCLUSIONS: Cold exposure represents a main stimulus for increased thermogenic capacity in human white adipocytes; however, this may have no impact on body weight loss. Chronic exercise may represent no major stimulus for UCP1 induced in human white adipocytes, while in animals it increases UCP1 gene independently of their diet. Therefore, evidence from animal studies regarding UCP1 gene activation in white adipocytes may not be applicable in humans. Finally, the identification of human WAT thermogenic capacity via PET/CT examination may be optimal with both a cooling and a non-cooling protocol.
    • Validation of the Polar RS800CX for assessing heart rate variability during rest, moderate cycling and post-exercise recovery

      Tsitoglou, Kyriakos; Koutedakis, Yiannis; Dinas, Petros (F1000Research, 2018-09-20)
      Background: Heart rate variability (HRV) is an autonomic nervous system marker that provides reliable information for both disease prevention and diagnosis; it is also used in sport settings. We examined the validity of the Polar RS800CX heart rate monitor during rest, moderate cycling, and recovery in considering the total of 24 HRV indices. Method: A total of 32 healthy males (age=24.78±6.87 years, body mass index=24.48±3.13 kg/m 2 ) completed a session comprised by three 20-minute time periods of resting, cycling at 60% of maximal heart rate, and recovery using a Polar RS800CX and an electrocardiogram (ECG) monitors. The HRV indices included time-domain, frequency-domain, Poincaré plot and recurrence plot. Bland–Altman plot analysis was used to estimate agreement between Polar RS800CX and ECG. Results: We detected significant associations (r>0.75, p<0.05) in all HRV indices, while five out of 24 HRV indices displayed significant mean differences (p<0.05) between Polar RS800CX and ECG during the resting period. However, for the exercise and recovery periods, we found significant mean differences (p<0.05) in 16/24 and 22/24 HRV indices between the two monitors, respectively. Conclusion: It is concluded that Polar RS800CX is a valid tool for monitoring HRV in individuals at resting conditions, but it displays inconsistency when used during exercise at 60% of maximal heart rate and recovery periods.