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Mantzios K, Ioannou LG, Panagiotaki Z, Ziaka S, Périard JD, Racinais S, Nybo L, Flouris AD. Effects of Weather Parameters on Endurance Running Performance: Discipline Specific Analysis of 1258 Races. Med Sci Sports Exerc. 2022 Jan 1;54(1):153-161. doi: 10.1249/MSS.0000000000002769. Abstract Introduction: This study evaluated how single or combinations of weather parameters (temperature, humidity, wind speed, solar load) affect peak performance during endurance running events and identify which events are most vulnerable to varying weather conditions. Methods: Results for the marathon, 50 km race-walk, 20 km race-walk, 10,000 m, 5,000 m and 3,000 m-steeplechase were obtained from the official websites of large competitions. We identified meteorological data from nearby (8.9 ± 9.3 km) weather stations for 1258 races held between 1936 and 2019 across 42 countries, enabling analysis of 7867 athletes. Results: The Wet-Bulb Globe Temperature (WBGT) across races ranged from -7 to 33 °C, with 27% of races taking place in cold/cool, 47% in...

Ioannou L.G., Gkikas G., Mantzios K., Tsoutsoubi L., Flouris A.D. Risk assessment for heat stress during work and leisure - Chapter 32. Toxicological Risk Assessment and Multi-System Health Impacts from Exposure 2021, Pages 373-385. Abstract Rising environmental temperatures have become a growing challenge for societies across the globe. At the same time, occupational heat strain undermines the health and productivity of individuals working in key industries. In this chapter, we combine a narrative review with observational studies to outline the 18 factors affecting the risk for experiencing heat strain during work and leisure, which are: acclimatization, aging, anthropometrics, clothing, cultural habits, diet, disabilities, drugs and addictions, environmental stress, ethnicity, heat mitigation, medical conditions, metabolic demands, physical fitness, sex, sleep deprivation, work duration, and work experience. Addressing these risk factors will generate significant savings to healthcare systems from the occupational heat illness, absenteeism, and mortality associated with heat strain. Increased efforts should be...

Nintou E, Karligiotou E, Vliora M, Fatouros IG, Jamurtas AZ, Sakellaridis N, Dimas K, Flouris AD. Effects of In Vitro Muscle Contraction on Thermogenic Protein Levels in Co-Cultured Adipocytes. Life (Basel). 2021 Nov 12;11(11):1227. doi: 10.3390/life11111227. Abstract: The crosstalk between the exercising muscle and the adipose tissue, mediated by myokines and metabolites, derived from both tissues during exercise has created a controversy between animal and human studies with respect to the impact of exercise on the browning process. The aim of this study was to investigate whether co-culturing of C2C12 myotubes and 3T3-L1 adipocytes under the stimuli of electrical pulse stimulation (EPS) mimicking muscle contraction can impact the expression of UCP1, PGC-1a, and IL-6 in adipocytes, therefore providing evidence on the direct crosstalk between adipocytes and stimulated muscle cells. In the co-cultured C2C12 cells, EPS increased the expression of PGC-1a (p = 0.129; d = 0.73) and IL-6 (p = 0.09;...

Foster J, Smallcombe JW, Hodder S, Jay O, Flouris AD, Havenith G. Quantifying the impact of heat on human physical work capacity; part II: the observed interaction of air velocity with temperature, humidity, sweat rate, and clothing is not captured by most heat stress indices. Int J Biometeorol. 2021 Nov 6. doi: 10.1007/s00484-021-02212-y. Online ahead of print. Abstract Increasing air movement can alleviate or exacerbate occupational heat strain, but the impact is not well defined across a wide range of hot environments, with different clothing levels. Therefore, we combined a large empirical study with a physical model of human heat transfer to determine the climates where increased air movement (with electric fans) provides effective body cooling. The model allowed us to generate practical advice using a high-resolution matrix of temperature and humidity. The empirical study involved a total of 300 1-h work trials in a variety of environments (35, 40, 45, and...

Quantifying the impact of heat on human physical work capacity; part III: the impact of solar radiation varies with air temperature, humidity, and clothing coverageFoster J, Smallcombe JW, Hodder S, Jay O, Flouris AD, Nybo L, Havenith G. Int J Biometeorol. 2021 Oct 28. doi: 10.1007/s00484-021-02205-x. Online ahead of print. Abstract Heat stress decreases human physical work capacity (PWC), but the extent to which solar radiation (SOLAR) compounds this response is not well understood. This study empirically quantified how SOLAR impacts PWC in the heat, considering wide, but controlled, variations in air temperature, humidity, and clothing coverage. We also provide correction equations so PWC can be quantified outdoors using heat stress indices that do not ordinarily account for SOLAR (including the Heat Stress Index, Humidex, and Wet-Bulb Temperature). Fourteen young adult males (7 donning a work coverall, 7 with shorts and trainers) walked for 1 h at a fixed heart rate of...

García-León D., Casanueva A., Standardi G., Burgstall A., Flouris A.D., Nybo L. Current and projected regional economic impacts of heatwaves in Europe. Nat Commun. 2021 Oct 4;12(1):5807. doi: 10.1038/s41467-021-26050-z. Abstract Extreme heat undermines the working capacity of individuals, resulting in lower productivity, and thus economic output. Here we analyse the present and future economic damages due to reduced labour productivity caused by extreme heat in Europe. For the analysis of current impacts, we focused on heatwaves occurring in four recent anomalously hot years (2003, 2010, 2015, and 2018) and compared our findings to the historical period 1981-2010. In the selected years, the total estimated damages attributed to heatwaves amounted to 0.3-0.5% of European gross domestic product (GDP). However, the identified losses were largely heterogeneous across space, consistently showing GDP impacts beyond 1% in more vulnerable regions. Future projections indicate that by 2060 impacts might increase in Europe by a factor of almost...

Notley SR, Akerman AP, Friesen BJ, Poirier MP, Sigal RJ, Flouris AD, Boulay P, McCourt E, Ruzicka M, Kenny GP. Heat Tolerance and Occupational Heat Exposure Limits in Older Men with and without Type 2 Diabetes or Hypertension. Med Sci Sports Exerc. 2021 Oct 1;53(10):2196-2206. doi: 10.1249/MSS.0000000000002698. Abstract Purpose: To mitigate rises in core temperature >1°C, the American Conference of Governmental Industrial Hygienists (ACGIH) recommends upper limits for heat stress (action limit values [ALV]), defined by wet-bulb globe temperature (WBGT) and a worker's metabolic rate. However, these limits are based on data from young men and are assumed to be suitable for all workers, irrespective of age or health status. We therefore explored the effect of aging, type 2 diabetes (T2D), and hypertension (HTN) on tolerance to prolonged, moderate-intensity work above and below these limits. Methods: Core temperature and heart rate were assessed in healthy, heat unacclimatized young (18-30 yr, n = 13)...

Amorim T, Freitas L, Metsios GS, Gomes TN, Wyon M, Flouris AD, Maia J, Marques F, Nogueira L, Adubeiro N, Koutedakis Y. Associations between nutrition, energy expenditure and energy availability with bone mass acquisition in dance students: a 3-year longitudinal study. Arch Osteoporos. 2021 Sep 24;16(1):141. doi: 10.1007/s11657-021-01005-5. Abstract Three years of study showed that female and male vocational dancers displayed lower bone mass compared to controls, at forearm, lumbar spine and femoral neck. Energy intake was found to positively predict bone mass accruals only in female dancers at femoral neck. Vocational dancers can be a risk population to develop osteoporosis. Purpose: To determine whether risk factors normally associated with low bone mass in athletic populations (i.e. nutrition intake, energy expenditure and energy availability) are significant predictors of bone mass changes in vocational dance students. Methods: The total of 101 vocational dancers (63 females, 12.8 ± 2.2 years; 38 males, 12.7 ± 2.2 years)...

Vakali E., Rigopoulos D., Carrillo A.E., Flouris A.D., Dinas P.C. Effects of alpha-lipoic acid supplementation on human diabetic nephropathy: A systematic review and meta-analysis. Curr Diabetes Rev. 2021 Sep 13. doi: 10.2174/1573399817666210914103329. Online ahead of print. Abstract Background: Diabetic nephropathy (DN) is a kidney dysfunction, which occurs due to elevated urine albumin excretion rate and reduced glomerular filtration rate. Studies in animals have shown that alpha-lipoic acid (ALA) supplementation can reduce the development of DN. Objectives: We performed a systematic review and meta-analysis to examine the effects of ALA supplementation on biological indices (albumin, creatinine etc.) indicative of human DN. Methods: The searching procedure included the databases PubMed Central, Embase, Cochrane Library (trials) and Web of Science, (protocol registration: INPLASY 202060095). Results: We found that ALA supplementation decreased urine albumin 24h excretion rate in patients with diabetes [standardized mean difference=-2.27; confidence interval (CI)=(-4.09)-(-0.45); I2=98%; Z=2.44; p=0.01]. A subgroup analysis revealed that the studies examining only...

Tsoutsoubi L, Ioannou LG, Flouris AD. Mortality due to circulatory causes in hot and cold environments in Greece. Scand Cardiovasc J. 2021 Dec;55(6):333-335. doi: 10.1080/14017431.2021.1970801. Epub 2021 Sep 8. Abstract Ambient temperature can affect the survival rate of humans. Studies have shown a relationship between ambient temperature and mortality rate in hot and cold environments. This effect of ambient temperature on mortality seems to be more pronounced in older people. The aim of this study is to examine the effects of thermal stress on cardiovascular mortality and the associated relative risk per degree Celsius in Greek individuals ≥70 years old. Mortality data 1999-2012 were matched with the midday temperature. The present study found a higher circulatory mortality when ambient temperature is below or above the temperature range 6 to 39 °C. Full Text https://pubmed.ncbi.nlm.nih.gov/34494493/...