Influence of intervals of radiant heat on performance and pacing dynamics during rowing exercise

Abstract: The purpose of this study was to investigate whether intervals of radiant heat during thermoneutral exercise altered either the performance outcome or the dynamics of pacing within the exercise bout. Eleven male participants ( ; 56 ± 12 ml∙kg-1∙min-1) performed three 5000m exercise trials on a rowing ergometer in three different conditions, in a random order. The participants were either: non-warmed (NW), warmed (W), or periodically warmed in intervals throughout each trial (IW). Warming was achieved using radiant heat lamps to raise the localised environmental temperature from 18 ˚C to 35 ˚C. Intervals of warming were applied over fixed periods of the 5000m bouts between 1000-2000m (W1) and 3000-4000m (W2). The results of the experiment demonstrated that performance time and average power output of the 5000m matched intensity trials were not significantly different between conditions (p=0.10 ; p=0.189). However, the application of warming significantly reduced intra-trial power output during the first (W1) interval in the IW condition (p=0.03) but not during the second (W2) warming interval (p=0.10). Tsk increased by 0.51˚C (p=0.05) in response to the application of warming during W1 in the IW condition and by 0.15 ˚C in W2 (p=0.28). No significant between-condition differences were observed in Tc throughout the trials. These findings suggest that an abrupt change to environmental conditions brought about through intervals of radiant warming can affect the transient pacing dynamics of an exercise bout, but not necessarily impact overall performance time. Performance time appears unaffected by intervals of radiant heat during an exercise bout, although further work is required in more challenging dynamic environmental conditions

Drowning Survival in Icy Water: A Review

We conducted an extensive literature review using the search terms of “drowning” and “hypothermia” to discover the major factors related to differences in survival rate especially associated with hypothermic effects. Studies indicated that some differences in drowning survival could be identified associated with age, sex, length of submersion, reduced core body temperature, and quality of cardiopulmonary respiratory care. The variability of results associated with the large number of studies prevented us from making any recommendations about whether hypothermia can improve survival among either children or adults

Where Do People Drown? Encoding the Third Component of the 4W Model

When there is human activity in, above, or around an aquatic environment, a drowning incident may occur due to rescuer characteristics, casualty characteristics, location, and general circumstances (Avramidis, Butterly & Llewellyn, 2007). The aim of the current study was to identify locations where people drown. Qualitative content analysis was utilized to analyze drowning incident videos (n = 41), and semi-structured interviews were conducted of those involved in drowning incidents (n = 34). Drowning incidents may occur in any aquatic environment with a water depth that allows immersion or submersion, under a variety of environmental conditions where the ground in sloping, at any distance from safety, where anxiety is exists, in the absence or safety regulations, or when the law is breached

Who Drowns? Encoding the Second Component of the 4W Model

The aim of the current study was to identify the casualty characteristics that contribute to drowning according to the 4W model (Avramidis, Butterly & Llewellyn, 2007, 2009). Qualitative content analysis was utilized to analyze drowning incident videos (n = 41), and semistructured interviews of those involved in drowning incidents (n = 34). Results confirm that human activity in, on, and around an aquatic environment can lead to drowning, regardless of the casualty’s type, gender, age, ethnicity, and area of residence. Males far outnumber females as drowning victims. Younger persons were more likely to drown than were adults. Due to socioeconomic differences, Black people in our sample were likely to drown more often, while Whites who drowned were engaged in aquatic activities that lower socioeconomic individuals likely cannot afford or have access to. Nonswimmers, casualties who have lost consciousness, and nonresidents to specific aquatic environments also were the ones in the highest danger

Under What Circumstances Do People Drown? Encoding the Fourth Component of the 4W Model

The aim of the current study was to identify under what circumstances people drown using the 4W model (Avramidis, Butterly, Llewellyn, 2007). We used qualitative content analysis to analyze drowning incident videos (n = 41), and semi-structured interviews of those involved in drowning incidents (n = 34). Results confirmed that drowning incidents can occur at any time, although most likely during daylight, and during any season of the year, with summer most common. We observed that drowning can occur after engaging in just about any form of human activity, on, near, above or under the surface of a liquid (mainly water). Drownings with serious consequences often result when rescue and personal protective equipment is either absent or has insufficient quality. Almost any risky aquatic-related activity that doesn’t comply with appropriate safety procedures might lead to drowning. In response to drowning, we noted that a wide variety of rescue techniques might be used

The 4W Model of Drowning

The aim of the study was to develop a conceptual model of drowning incidents. The authors conducted qualitative content analysis of drowning-incident videos (n = 41), and semi-structured interviews of those involved in drowning incidents (n = 34), followed by the measurement of frequencies and Boolean search with matrix intersection. Results confirmed that when there is human activity in, above, or around an aquatic environment, a drowning incident may occur to whomever, wherever, and under whatever circumstance. Factors that determined drowning outcome were, in order of importance, rescuer characteristics (Who1), casualty characteristics (Who2), location (Wherever), and general circumstances (Whatever). The interaction of the rescuer with the casualty largely determines the outcome of drowning. The 4W model is a promising tool in lifesaving and lifeguarding