Glycogen levels in wildland firefighters during wildfire suppression.
Wilderness Environ Med
; 22(1): 23-7, 2011 Mar.
Article
em En
| MEDLINE
| ID: mdl-21377115
ABSTRACT
OBJECTIVE:
The purpose of this project was to determine the effects of wildfire suppression on muscle glycogen utilization in wildland firefighters (WLFFs).METHODS:
Wildland firefighters (n = 11) participated in the study. Muscle biopsies were obtained from the vastus lateralis pre- and post-work shift. Activity patterns were measured using an Actical activity monitor positioned on the chest. Food was consumed ad libitum and recorded using a food log and interview. Differences were analyzed using paired samples t-tests and relationships were assessed using Pearson r correlation coefficients. A significance level of p < .05 was set.RESULTS:
Body weight was similar pre- to post-work shift (85.9 ± 9.1 and 85.6 ± 8.8 kg, respectively). Muscle glycogen decreased from pre- to post-work shift, 101 ± 7 to 80 ± 5 mmol/kg wet wt, p < .05. Average activity counts were 175 ± 60 counts/min. Mean percent of time spent in each intensity category included sedentary (74 ± 7%), light (21 ± 5%), and moderate/vigorous (5 ± 2%). There was a significant relationship between minutes completing vigorous activity and glycogen utilization (r = -.76, p < .05), and between minutes spent completing vigorous activity and pre-shift glycogen content (r = .79, p < .05). Kilocalorie intake during the work shift was 9.2 ± 2.9 MJ/d (2195 ± 699 kcal/d).CONCLUSIONS:
This study demonstrates the variety of self-selected nutritional and activity habits of WLFFs, and emphasizes the relationships between moderate/vigorous activity and muscle glycogen. The current data suggest that the food provided was adequate to maintain muscle glycogen levels pre- to post-work shift.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ingestão de Energia
/
Músculo Esquelético
/
Esforço Físico
/
Incêndios
/
Glicogênio
Limite:
Female
/
Humans
/
Male
Idioma:
En
Revista:
Wilderness Environ Med
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos