Sex-specific analysis of hiking accidents in the Austrian Alps: a follow-up from 2015 to 2021.

Background: Hiking is one of the most popular leisure sport activities practiced in the Alps during the summer season, but bears the risk of mountain emergencies, accidents, and fatalities. This paper provides an updated analysis of hiking accidents for the years 2015 to 2021 in the Austrian Alps, thereby outlining fatal and non-fatal accident characteristics. Methods: For this retrospective analysis, mountain hiking accidents documented by the Austrian Alpine Police during a 7-year period were screened for potential exclusion criteria. The final sample size consisted of 7368 accidents and 7552 victims. The outcome measures were mainly specified by sex, age, injury degree, injury location, pathophysiological characteristics, and cause of injury. Results: The overall annual number of accidents showed a continuous increase from 428 in 2015 to 544 in 2021. In total, 7.1% of the total victims died during the 7-year period, with male hikers being significantly more affected than female hikers (m: 80.8%, f: 19.2%; p ≤ 0.001). The sex specific distribution for non-fatal hiking accidents was 55.9% in women and 44.1% in men. Male victims showed significantly more frequent cardiovascular events (m: 78.5%, f: 21.5%), multiple injuries (m: 60.2%, f: 39.8%), and wounds/blood loss (m: 57.4%, f: 42.6%) than female victims, whereas women showed more fractures (m: 31.5%, f: 68.5%) than men (p ≤ 0.001). Additionally, men were more likely to injure their abdomen/chest (3.7%), head (14.1%), and multiple body parts (26.5%), whereas women were more likely to injure their ankle or foot (42.3%). Finally, men were more likely to have an accident during the ascent (24.1%), whereas women during the descent (69.0%) (p ≤ 0.001). Conclusion: This paper provides the latest data and a deeper insight into sex-specific characteristics of mountain hiking accidents in the Austrian Alps.

Effects of Forearm Compression Sleeves on Muscle Hemodynamics and Muscular Strength and Endurance Parameters in Sports Climbing: A Randomized, Controlled Crossover Trial.

Purpose: Wearing compression garments is a commonly used intervention in sports to improve performance and facilitate recovery. Some evidence supports the use of forearm compression to improve muscle tissue oxygenation and enhance sports climbing performance. However, evidence is lacking for an effect of compression garments on hand grip strength and specific sports climbing performance. The purpose of this study was to evaluate the immediate effects of forearm compression sleeves on muscular strength and endurance of finger flexor muscles in sports climbers. Materials and Methods: This randomized crossover study included 24 sports climbers who performed one familiarization trial and three subsequent test trials while wearing compression forearm sleeves (COMP), non-compressive placebo forearm sleeves (PLAC), or no forearm sleeves (CON). Test trials consisted of three performance measurements (intermittent hand grip strength and endurance measurements, finger hang, and lap climbing) at intervals of at least 48 h in a randomized order. Muscle oxygenation during hand grip and finger hang measurements was assessed by near-infrared spectroscopy. The maximum blood lactate level, rate of perceived exertion, and forearm muscle pain were also determined directly after the lap climbing trials. Results: COMP resulted in higher changes in oxy[heme] and tissue oxygen saturation (StO2) during the deoxygenation (oxy[heme]: COMP -10.7 ± 5.4, PLAC -6.7 ± 4.3, CON -6.9 ± 5.0 [µmol]; p = 0.014, ηp 2 = 0.263; StO2: COMP -4.0 ± 2.2, PLAC -3.0 ± 1.4, CON -2.8 ± 1.8 [%]; p = 0.049, ηp 2 = 0.194) and reoxygenation (oxy [heme]: COMP 10.2 ± 5.3, PLAC 6.0 ± 4.1, CON 6.3 ± 4.9 [µmol]; p = 0.011, ηp 2 = 0.274; StO2: COMP 3.5 ± 1.9, PLAC 2.4 ± 1.2, CON 2.3 ± 1.9 [%]; p = 0.028, ηp 2 = 0.225) phases of hand grip measurements, whereas total [heme] concentrations were not affected. No differences were detected between the conditions for the parameters of peak force and fatigue index in the hand grip, time to failure and hemodynamics in the finger hang, or performance-related parameters in the lap climbing measurements (p ≤ 0.05). Conclusions: Forearm compression sleeves did not enhance hand grip strength and endurance, sports climbing performance parameters, physiological responses, or perceptual measures. However, they did result in slightly more pronounced changes of oxy [heme] and StO2 in the deoxygenation and reoxygenation phases during the hand grip strength and endurance measurements.

Alterations in acid-base balance and high-intensity exercise performance after short-term and long-term exposure to acute normobaric hypoxic conditions.

This investigation assessed the course of renal compensation of hypoxia-induced respiratory alkalosis by elimination of bicarbonate ions and impairments in anaerobic exercise after different durations of hypoxic exposure. Study A: 16 participants underwent a resting 12-h exposure to normobaric hypoxia (3,000 m). Blood gas analysis was assessed hourly. While blood pH was significantly increased, PO2, PCO2, and SaO2 were decreased within the first hour of hypoxia, and changes remained consistent. A substantial reduction in [HCO3-] levels was observed after 12 h of hypoxic exposure (- 1.35 ± 0.29 mmol/L, p ≤ 0.05). Study B: 24 participants performed in a randomized, cross-over trial portable tethered sprint running (PTSR) tests under normoxia and after either 1 h (n = 12) or 12 h (n = 12) of normobaric hypoxia (3,000 m). No differences occurred for PTSR-related performance parameters, but the reduction in blood lactate levels was greater after 12 h compared with 1 h (- 1.9 ± 2.2 vs 0.0 ± 2.3 mmol/L, p ≤ 0.05). These results indicate uncompensated respiratory alkalosis after 12 h of hypoxia and similar impairment of high-intensity exercise after 1 and 12 h of hypoxic exposure, despite a greater reduction in blood lactate responses after 12 h compared with 1 h of hypoxic exposure.

Effects of daily ingestion of sodium bicarbonate on acid-base status and anaerobic performance during an altitude sojourn at high altitude: a randomized controlled trial.

BACKGROUND: The present study investigated the effects of chronic sodium bicarbonate (NaHCO3) ingestion on a single bout of high-intensity exercise and on acid-base balance during 7-day high-altitude exposure. METHODS: Ten recreationally active subjects participated in a pre-test at sea level and a 7-day hiking tour in the Swiss Alps up to 4554 m above sea level. Subjects received either a daily dose of 0.3 g/kg NaHCO3 solution (n = 5) or water as a placebo (n = 5) for 7 days. Anaerobic high-intensity exercise performance was assessed using the portable tethered sprint running (PTSR) test under normoxic and hypoxic conditions (3585 m). PTSR tests assessed overall peak force, mean force, and fatigue index. Blood lactate levels and blood gas parameters were assessed pre- and post-PTSR. Urinary pH and blood gas parameters were further analyzed daily at rest in early morning samples under normoxic and hypoxic conditions. RESULTS: There were no significant differences between the bicarbonate and control group in any of the PTSR-related parameters. However, urinary pH (p = 0.003, ηp2 = 0.458), early morning blood bicarbonate concentration (p < 0.001, ηp2 = 0.457) and base excess (p = 0.002, ηp2 = 0.436) were significantly higher in the bicarbonate group compared with the control group under hypoxic conditions. CONCLUSIONS: These results indicate that oral NaHCO3 ingestion does not ameliorate the hypoxia-induced impairment in anaerobic, high-intensity exercise performance, represented by PTSR-related test parameters, under hypobaric, hypoxic conditions, but the maximal performance measurements may have been negatively affected by other factors, such as poor implementation of PTSR test instructions, pre-acclimatization, the time course of hypoxia-induced renal [HCO3-] compensation, changes in the concentrations of intra- and extracellular ions others than [H+] and [HCO3-], or gastrointestinal disturbances caused by NaHCO3 ingestion. However, chronic NaHCO3 ingestion improves blood bicarbonate concentration and base excess at altitude, which partially represent the blood buffering capacity.

Effects of an Alkalizing or Acidizing Diet on High-Intensity Exercise Performance under Normoxic and Hypoxic Conditions in Physically Active Adults: A Randomized, Crossover Trial.

Pre-alkalization caused by dietary supplements such as sodium bicarbonate improves anaerobic exercise performance. However, the influence of a base-forming nutrition on anaerobic performance in hypoxia remains unknown. Herein, we investigated the effects of an alkalizing or acidizing diet on high-intensity performance and associated metabolic parameters in normoxia and hypoxia. In a randomized crossover design, 15 participants (24.5 ± 3.9 years old) performed two trials following four days of either an alkalizing (BASE) or an acidizing (ACID) diet in normoxia. Subsequently, participants performed two trials (BASE; ACID) after 12 h of normobaric hypoxic exposure. Anaerobic exercise performance was assessed using the portable tethered sprint running (PTSR) test. PTSR assessed overall peak force, mean force, and fatigue index. Blood lactate levels, blood gas parameters, heart rate, and rate of perceived exertion were assessed post-PTSR. Urinary pH was analyzed daily. There were no differences between BASE and ACID conditions for any of the PTSR-related parameters. However, urinary pH, blood pH, blood bicarbonate concentration, and base excess were significantly higher in BASE compared with ACID (p < 0.001). These findings show a diet-induced increase in blood buffer capacity, represented by blood bicarbonate concentration and base excess. However, diet-induced metabolic changes did not improve PTSR-related anaerobic performance.

Acute effects of kinesio taping on muscular strength and endurance parameters of the finger flexors in sport climbing: A randomised, controlled crossover trial.

Kinesio taping (KT) is a commonly used intervention in sports and, recently, KT has become popular among athletes competing in sport climbing and bouldering events. However, evidence on the effect of KT on grip strength and endurance is still controversial. Therefore, the purpose of this study was to evaluate immediate effects of KT on muscular strength and endurance of the finger flexor muscles in sport climbers. Twenty recreationally-trained active sport climbers (10 men, 10 women) aged 28.5 ± 10.6 years performed one familiarisation trial and subsequently, in a randomised crossover design, two test trials either with (TAPE) or without (CONTROL) KT over the finger flexor muscles. Test trials consisted of three performance measurements (hand grip strength and endurance, finger hang, and lap climbing) at intervals of 48 h in a randomised order. We observed no significant differences in the parameters of hand grip peak force, fatigue index, finger hang time, lap climbing distance and time, or maximum blood lactate values after lap climbing between the TAPE and CONTROL trials (p > 0.05). The participants' climbing ability was significantly correlated with the intra-individual performance changes between the TAPE and CONTROL conditions for the fatigue index (r = -0.598, p = 0.005), but not in any of the other performance-related parameters. Therefore, KT over the finger flexor muscles neither enhanced hand grip strength and endurance nor the sport climbing performance parameters of finger hang, lap climbing distance and time, and maximum blood lactate values after lap climbing.

Influence of Natural Hypobaric Hypoxic Conditions on Dynamic Visual Performance.

Background: Both dynamic and static visual performances are essential for safety and motoric performance at altitude. There is a lack of information regarding alterations in dynamic visual performance (DVP) in oxygen-reduced environments. The purpose of this study was to analyze DVP in natural hypoxic conditions in a group of young, healthy hikers. Methods: DVP in four parafoveal subfields was analyzed using the computer-assisted Düsseldorf Test for Dynamic Vision. Measurements were performed twice at altitudes above 3500 m during an 8-day alpine hike. Results: On day 5 (3647 m), no changes in DVP were detected. On day 6 (4554 m), however, we found a significant reduction in DVP in the superior parafoveal retinal subfield, partly representing the lower visual field. The observed changes did not correlate with oxygen saturation, hematocrit, or cardiovascular parameters. We found no interrelation between symptoms of acute mountain sickness and DVP at altitude. Conclusions: Our data suggest that hiking at altitudes above 4500 m results in lower DVP in the visual field of healthy young people. The alteration might affect motor performance and coordination, increasing the risk of accidents.

Reliability and Validity of a New Portable Tethered Sprint Running Test as a Measure of Maximal Anaerobic Performance.

Limmer, M, Berkholz, A, de Marées, M, and Platen, P. Reliability and validity of a new portable tethered sprint running test as a measure of maximal anaerobic performance. J Strength Cond Res 34(8): 2197-2204, 2020-The purposes of this study were to develop a new portable tethered sprint running (PTSR) test for field-based anaerobic performance testing with restricted spatial conditions and the logistical challenge of carrying test equipment, and to determine reliability of the PTSR test. For validity, performance measures were compared with the cycle ergometer Wingate Anaerobic Test (WAnT) power outputs. Twelve recreationally active men and women (24.3 ± 1.6 years; 1.77 ± 0.07 m; 73.3 ± 12.5 kg) performed one familiarization trial followed by 3 randomly assigned experimental 60-second all-out effort trials consisting of one WAnT and 2 PTSR tests. All trials were performed in a randomized order on different days separated by at least 48 hours. Heart rate (HR) and maximum blood lactate concentration were recorded for each experimental trial to determine the physiological responses to the maximal efforts. Correlation coefficients indicated significant relationships between mean force (MF) and peak force (PF) in the PTSR test and mean power (MP) (r = 0.651, p = 0.022) and peak power (PP) (r = 0.877, p = 0.002) in the WAnT, but not for the fatigue index (r = 0.280, p = 0.379). In addition, both PTSR trials showed no significant differences (p > 0.05) between trials and a high reliability for the performance variables MF (intraclass correlation coefficient [ICC] = 0.98, coefficient of variation [%CV] = 7.7), PF (ICC = 0.98, %CV = 8.4), and HR (ICC = 0.92, %CV = 3.1). In conclusion, our results suggest that despite insufficient stimulation of anaerobic metabolism in some subjects resulting from poor implementation of test instructions, the PTSR is a reliable and valid test for an easy and practical assessment of maximal anaerobic performance under different field conditions.

The influence of hypoxia and prolonged exercise on attentional performance at high and extreme altitudes: A pilot study.

INTRODUCTION: Exposure to hypoxic conditions is reported to impair cognitive performance. Further, moderate physical exercise improves cognitive function, but little is known about the influence of exercise on cognitive function in hypoxia. Therefore, the current study aimed to examine the influence of hypoxia (HYP) and prolonged exercise (EX) on attentional performance. METHODS: A total of 80 participants (female: n = 29; male: n = 51) were assigned to four groups: HYP + EX (n = 15), HYP (n = 25), EX (n = 21) and normoxia (NOR) (n = 21). The Frankfurt Attention Inventory-2 (FAIR-2) was performed at four testing points (day 1, 14, 16 and 18) to assess attentional performance. All groups completed a pretest (D1) and a follow-up test (D18). In HYP + EX conditions, the cognitive task was performed in a hypoxic state after prolonged exercise (D14: 3950 m, D16: 5739 m) during a mountain climb on Mt. Kilimanjaro. Participants in HYP were tested under intermittent hypoxia at rest in a hypoxic chamber (D14: 3500 m, D16: 5800 m), and those in EX were tested under normoxia after prolonged exercise during a 7-day backcountry ski hiking tour. NOR was a control group, and participants completed all tests under normoxia and at rest. RESULTS: Hypoxia impaired the attentional functions performance value (PV) and continuity value (CV) for the HYP + EX (p = 0.000) and HYP (L: p = 0.025; K: p = 0.043) groups at 5739 m and 5800 m, respectively, but not the function quality value (QV). In contrast, the EX group did not exhibit changes in attentional function. CONCLUSION: The current results suggest that attentional performance is impaired during extreme normobaric and hypobaric hypoxic exposure. We further conclude that greater cognitive impairment under hypobaric hypoxia during a mountain climb compared with normobaric hypoxia at rest is not caused by prolonged exercise, but may be influenced by other factors (e.g. low temperatures, dehydration, or sleep deprivation) that remain to be verified.

Enhanced 400-m sprint performance in moderately trained participants by a 4-day alkalizing diet: a counterbalanced, randomized controlled trial.

BACKGROUND: Sodium bicarbonate (NaHCO3) is an alkalizing agent and its ingestion is used to improve anaerobic performance. However, the influence of alkalizing nutrients on anaerobic exercise performance remains unclear. Therefore, the present study investigated the influence of an alkalizing versus acidizing diet on 400-m sprint performance, blood lactate, blood gas parameters, and urinary pH in moderately trained adults. METHODS: In a randomized crossover design, eleven recreationally active participants (8 men, 3 women) aged 26.0 ± 1.7 years performed one trial under each individual's unmodified diet and subsequently two trials following either 4 days of an alkalizing (BASE) or acidizing (ACID) diet. Trials consisted of 400-m runs at intervals of 1 week on a tartan track in a randomized order. RESULTS: We found a significantly lower 400-m performance time for the BASE trial (65.8 ± 7.2 s) compared with the ACID trial (67.3 ± 7.1 s; p = 0.026). In addition, responses were significantly higher following the BASE diet for blood lactate (BASE: 16.3 ± 2.7; ACID: 14.4 ± 2.1 mmol/L; p = 0.32) and urinary pH (BASE: 7.0 ± 0.7; ACID: 5.5 ± 0.7; p = 0.001). CONCLUSIONS: We conclude that a short-term alkalizing diet may improve 400-m performance time in moderately trained participants. Additionally, we found higher blood lactate concentrations under the alkalizing diet, suggesting an enhanced blood or muscle buffer capacity. Thus, an alkalizing diet may be an easy and natural way to enhance 400-m sprint performance for athletes without the necessity of taking artificial dietary supplements.