Immediate exercise hyperemia in humans is contraction intensity dependent: evidence for rapid vasodilation. J Appl Physiol 96: 639-644, 2004. First published October 24, 2003 10.1152/japplphysiol.00769. 2003.-We tested the hypothesis that rapid vasodilation proportional to contraction intensity contributes to the immediate (first cardiac cycle after initial contraction) exercise hyperemia. Ten healthy subjects performed single 1-s isometric forearm contractions at 5,10,15,20, 30, 50, and 70% maximal voluntary contraction intensity (MVC) in arm above heart (AH) and below heart (BH) positions. Forearm blood flow (FBF; brachial artery mean blood velocity, Doppler ultrasound), mean arterial pressure (arterial tonometry), and heart rate (electrocardiogram) were measured beat by beat. Venous emptying (measured with a forearm strain gauge) was already maximized at 5% MVC, indicating that increases in contraction intensity did not further empty the forearm veins. Immediate increases in FBF were linearly proportional to contraction intensity from 5 to 70% MVC in AH (slope ϭ 4.4 Ϯ 0.5%⌬FBF/%MVC). In BH, the immediate increase in FBF demonstrated a curvilinear relationship with increasing contraction intensity and was greater than AH at 15, 20, 30, and 50% MVC (P Ͻ 0.05). Peak changes in FBF were greater in BH vs. AH from 10 to 50% MVC, even when venous refilling was complete (P Ͻ 0.05). These data support the existence of a rapid-acting vasodilatory mechanism(s) at the onset of human forearm exercise. muscle blood flow; muscle pump IN A REST-TO-EXERCISE TRANSITION, muscle blood flow typically increases in a biphasic manner to a steady-state level proportional to muscle metabolic demand (7,12,17). A striking characteristic of this adaptation is the immediate and substantial increase in muscle blood flow after release of the first contraction of exercise (11-13, 18, 21). Because blood flow through a muscle vascular bed is thought to be proportional to 1) the arteriovenous pressure difference across that bed and 2) the vascular conductance of that bed, a number of studies have been conducted to determine whether the muscle pump, vasodilation, or both play an immediate role in the hyperemia at the onset of exercise (9,11,12,21,23). Considerable evidence for a muscle pump contribution exists, but whether the muscle pump is the exclusive contributor or whether a rapid vasodilatory mechanism(s) exists remains controversial.Studies that support an exclusive muscle pump effect have examined the onset of mild or moderate locomotion in dogs or rats walking on a treadmill. These studies demonstrate that the magnitude of the initial rapid adjustment in blood flow is related to speed (contraction frequency) not grade (contraction intensity) (11, 12). More invasive studies have used video microscopy in situ to directly measure the time course of vessel diameter responses to muscle stimulation or direct application of known vasodilators to microvessels (3,8,23). These studies suggest that the onset of vasodilation exhibits a 4-to 6-s d...

The purpose of this study was to examine meanings of play among children. Thirty-eight students aged 7-9 years from a suburban public school in Western Canada participated in focus groups. Data analysis revealed participants saw almost anything as an opportunity for play and would play almost anywhere with anyone. However, they perceived parents to have somewhat different views regarding play. The children frequently described adults as restricting play opportunities. This study therefore revealed that children had a relatively unrestrained view of play and these findings may be useful for helping to ensure that adults facilitate, rather than hinder, children's play.

No abstract

The media has the ability to affect public opinion and policy direction. Prevalence of morbid obesity in Canada is increasing; as is the only effective long-term treatment, weight loss surgery (WLS). Limited research has explored media re/presentations of WLS. The purpose of this study was to examine national online news coverage (and reader comments) of WLS using content analysis. We sought to understand the dominant messages being conveyed within the news texts and reader comments, specifically whose voice was represented, who was the intended audience and what was the overall tone. Articles and comments were retrieved from the Canadian Broadcasting Corporation news web site and analysed using line-by-line techniques. Articles were predominantly 'positive/supportive' (63%) in tone and frequently presented the voices and opinions of 'experts' conveying a biomedical perspective. Comments were overwhelmingly 'negative' (56%) and often derogatory including such language as 'piggy' and 'fatty'. Comments were almost exclusively anonymous (99%) and were frequently directed at other commenters (33%) and 'fat' people (6%). The potentially problematic nature of media framing and reader comments, particularly as they could relate to weight-based stigmatization and discrimination is discussed.

Weight loss surgery (WLS) is gaining ground as the most effective treatment against obesity. In the literature, however, we see a divide among individuals who have undergone WLS based on the amount of weight lost and maintained: successful and unsuccessful patients. In this article, we focus on the notion of unsuccessful patients-exploring the accounts of three women who have regained weight following WLS. In doing so, we endeavor to better understand how weight regain has meaning, and its impact and implications for the lives of individuals who undergo WLS. The findings reveal how weight-regain stories are easily silenced, buried beneath social, cultural, and institutional/medical narratives of successful weight loss and transformation. People who have such experiences may feel reticent to reveal them and in doing so increase their own suffering, therefore leaving the popular narratives unchallenged.

PA counseling in addition to standard care is effective for promoting PA behavior change and positive health-related outcomes among individuals with T2DM.

Scholars have problematized popular culture and media (re)presentations of obesity/overweight. However, few have considered the ways bariatric surgery, a rapidly growing treatment for morbid obesity, fits within the discussion. In this article, we explore news media (re)presentations of bariatric surgery using an eclectic approach to critical discourse analysis. Our findings reveal dominant discourses about bariatric surgery and the surgical population, providing an understanding of media (re)presentations as possible contributors to bias, stigmatization, and discrimination. Novel in our findings was our identification of subject positions in the dominant discourses (which were biomedical and benevolent government). We argue that existing (re)presentations of bariatric surgery are highly problematic because they reinforce oversimplistic and binary understandings of weight-loss surgery and obesity, weaving a highly gendered fairy-tale narrative and ultimately promoting weight-based stigmatization.

No abstract