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Cold stress and hypoxia have been the subject of research for decades; however, humans often encounter these stressors together, such as in the alpine environment. Therefore, this review summarizes previous data with respect to the influence of hypoxia on thermoregulatory and cardiovascular control in the cold and presents new ideas for the future. Altogether, little to no evidence is available on the integrative and adaptive mechanisms by which the human body regulates heat conservation, oxygen delivery and maintenance of blood pressure.

IntroductionAnnually, 2 million sports-related injuries are reported in Germany of which athletes contribute to a large proportion. Multiple sport injury prevention programs designed to decrease acute and overuse injuries in athletes have been proven effective. Yet, the programs’ components, general or sports-specific, that led to these positive effects are uncertain. Despite not knowing about the superiority of sports-specific injury prevention programs, coaches and athletes alike prefer more specialized rather than generalized exercise programs. Therefore, this systematic review aimed to present the available evidence on how general and sports-specific prevention programs affect injury rates in athletes.MethodsPubMed and Web of Science were electronically searched throughout April 2018. The inclusion criteria were publication dates Jan 2006–Dec 2017, athletes (11–45 years), exercise-based injury prevention programs and injury incidence. The methodological quality was assessed with the Cochrane Collaboration assessment tools.ResultsOf the initial 6619 findings, 15 studies met the inclusion criteria. In addition, 13 studies were added from reference lists and external sources making a total of 28 studies. Of which, one used sports-specific, seven general and 20 mixed prevention strategies. Twenty-four studies revealed reduced injury rates. Of the four ineffective programs, one was general and three mixed.ConclusionThe general and mixed programs positively affect injury rates. Sports-specific programs are uninvestigated and despite wide discussion regarding the definition, no consensus was reached. Defining such terminology and investigating the true effectiveness of such IPPs is a potential avenue for future research.

Passive heating has emerged as a therapeutic intervention for the treatment and prevention of cardiovascular disease. Like exercise, heating increases peripheral artery blood flow and shear rate which is thought to be a primary mechanism underpinning endothelium mediated vascular adaptation. However, few studies have compared the increase in arterial blood flow and shear rate between dynamic exercise and passive heating. In a fixed crossover design study, 15 moderately trained healthy participants (25.6 ± 3.4 years) (5 female) underwent 30 minutes of whole body passive heating (42 °C bath), followed on a separate day by 30 minutes of semi-recumbent stepping exercise performed at two workloads corresponding to the increase in cardiac output (Qc) (Δ3.72 l∙min-1) and heart rate (HR) (Δ38 bpm) recorded at the end of passive heating. Results: At the same Qc (Δ3.72 l∙min-1 vs 3.78 l∙min-1), femoral artery blood flow (1599 ml/min vs 1947 ml/min) (p=0.596) and shear rate (162 s -1 vs 192 s-1) (p=0.471) measured by ultrasonography were similar between passive heating and stepping exercise. However, for the same HR matched intensity, femoral blood flow (1599 ml·min-1 vs 2588 ml·min-1) and shear rate (161s-1 vs 271s-1) were significantly greater during exercise, compared with heating (both P=<0.001). The results indicate that, for moderately trained individuals, passive heating increases common femoral artery blood flow and shear rate similar to low intensity continuous dynamic exercise (29% VO2max), however exercise performed at a higher intensity (53% VO2max) results in significantly larger shear rates towards the active skeletal muscle.

This study aims to evaluate the agreement in maximum oxygen consumption (V˙O2max) between a running protocol and a ski mountaineering (SKIMO) protocol. Eighteen (eleven males, seven females) ski mountaineers (age: 25 ± 3 years) participated in the study. V˙O2max, maximum heart rate (HRmax), and maximum blood lactate concentration (BLAmax) were determined in an incremental uphill running test and an incremental SKIMO-equipment-specific test. V˙O2max did not differ between the SKIMO and uphill running protocols (p = 0.927; mean difference –0.07 ± 3.3 mL/min/kg), nor did HRmax (p = 0.587, mean difference –0.7 ± 5.1 bpm). A significant correlation was found between V˙O2max SKIMO and V˙O2max running (p ≤ 0.001; ICC = 0.862 (95% CI: 0.670−0.946)). The coefficient of variation was 4.4% (95% CI: 3.3−6.5). BLAmax was significantly lower for SKIMO compared to running (12.0 ± 14.1%; p = 0.002). This study demonstrates that V˙O2max determined with a traditional uphill running protocol demonstrates good agreement with an equipment-specific SKIMO protocol.