9 research outputs found
Hyponatremia in a Cold Weather Ultraendurance Race
We assessed the incidence and etiology of hyponatremia in the 100-mile (161 km) Iditasport ultramarathon. Subjects (8 cyclists, 8 runners) were weighed and serum sodium was measured pre- and post-race. Race diets were analyzed to determine fluid and sodium consumption. Subjects were split by post-race serum sodium concentration into hyponatremic and normonatremic groups for statistical analyses. Seven of 16 subjects (44%) were hyponatremic. The hyponatremic group exhibited a significant decrease in serum sodium concentration (137.0 to 132.9 mmol/L, and the normonatremic group experienced a significant decrease in weight (82.1 to 80.2 kg) pre- to post-race. The hypornatremic group drank more friud per hour (0.5 versus 0.4 L/h) and consumed less sodium per hour (235 versus 298 mg/h) compared to the normonatremic group. In conclusion, hyponatremia is common in an ultraendurance race held in the extreme cold, and may be caused by excessive fluid consumption and/or inadequate sodium intake
The steelband movement in Trinidad and Tobago: Music, politics and national identity in a New World society
The steelband emerged in Trinidad in the late 1930s as a new form of Carnival street music. The creators of the first pans (steelband instruments) were primarily young, Afro-Trinidadian men who belonged to the grass-roots sector of the society: the working class, the marginally employed and the unemployed. Initially, steelband music was perceived by the middle and upper class as a disturbance of the social order, and efforts were made to restrict its performance. By the late 1940s, however, some prominent citizens with nationalist sentiments were affirming the steelband as an innovative local art. By the 1950s, panmen were performing at a wide range of social occasions, some middle-class youths had begun forming bands of their own, and the movement as a whole had received the official support of the government. When Trinidad and Tobago gained its independence from Britain in 1962, the steelband was already a symbol of national identity. Today, the steelband movement is simultaneously based in grass-roots communities and closely connected with the formal institutional structure of Trinidadian society. Bands have up to one hundred members each and play intricate arrangements of local calypsoes, North American and Latin American popular tunes, and European classics. Performance occasions range from the streets at Carnival to the concert hall stage. The gradual transformation and current status of the steelband movement are examined in the present study from historical and ethnographic perspectives. Conclusions are based on field observation, interviews, newspaper articles and other written sources. Particular attention is given to how the use and significance of the steelband have been negotiated by different ethnic groups, classes and institutions in the society. It is suggested that the emergence and development of the steelband parallel the emergence and development of Trinidad and Tobago as a nation. The social dramas of the steelband movement have been part of broader patterns of ethnic and class relations in nation-building; and steelband performances have been an important vehicle through which the nation creatively explores various visions of its identity
Hormonal responses to a 160-km race across frozen Alaska
Background: Severe physical and environmental stress seems to have a suppressive effect on the hypothalamicâpituitaryâgonadal (HPG) axis in men. Examining hormonal responses to an extreme 160-km competition across frozen Alaska provides a unique opportunity to study this intense stress. Objective: To examine hormonal responses to an ultra-endurance race.
Methods: Blood samples were obtained from 16 men before and after racing and analyzed for testosterone, interleukin-6 (IL-6), growth hormone (GH) and cortisol. Six subjects (mean (SD) age 42 (7) years; body mass 78.9 (7.1) kg; height 1.78 (0.05) m raced by bicycle (cyclists) and 10 subjects (age 35 (9) years; body mass 77.9 (10.6) kg; height, 1.82 (0.05) m) raced by foot (runners). Mean (SD) finish times were 21.83 (6.27) and 33.98 (6.12) h, respectively.
Results: In cyclists there were significant (p?0.05) mean (SD) pre-race to post-race increases in cortisol (254.83 (135.26) to 535.99 (232.22) nmol/l), GH (0.12 (0.23) to 3.21 (3.33) ”g/ml) and IL-6 (2.36 (0.42) to 10.15 (3.28) pg/ml), and a significant decrease in testosterone (13.81 (3.19) to 5.59 (3.74) nmol/l). Similarly, in runners there were significant pre-race to post-race increases in cortisol (142.09 (50.74) to 452.21 (163.40) ng/ml), GH (0.12 (0.23) to 3.21 (3.33) ”g/ml) and IL-6 (2.42 (0.68) to 12.25 (1.78) pg/ml), and a significant decrease in testosterone (12.32 (4.47) to 6.96 (3.19) nmol/l). There were no significant differences in the hormonal levels between cyclists and runners (p>0.05).
Conclusions: These data suggest a suppression of the hypopituitaryâgonadal axis potentially mediated by amplification of adrenal stress responses to such an ultra-endurance race in environmentally stressful conditions