Premium
Circadian rhythm of spontaneous activity and body temperature and its relationship with exercise capacity
Author(s) -
Machado Frederico Sander Mansur,
Rodovalho Gisele Veira,
Coimbra Cândido Celso
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.802.2
Subject(s) - circadian rhythm , thermoregulation , endocrinology , medicine , chemistry , zoology , psychology , biology
The aim of this study was to verify relationships between circadian spontaneous activity and body temperature (T b ) with exercise capacity in two different phases of light/dark cycle. Circadian activity and T b of Wistar rats (n=11), under regular environmental conditions with free access to water and food, were continuously recorded using a telemetric sensor (G2 E‐Mitter) chronically implanted (ip) 3 days before. We accessed total time to fatigue, workload and T b during exercise. Animals were submitted to progressive exercise test protocols until fatigue during the early light and dark phases. Each test was separated for 3 days. Fatigue was set as the moment when rats couldn't keep pace with treadmill. Results suggest increased circadian dark phase activity compared to light phase (p<0.01). This was accompanied by greater light phase exercise capacity and T b variance and heat accumulation (p<0.05). There was no direct relationship of circadian activity and exercise capacity although at light phase a specific negative relationship of circadian temperature and exercise capacity was observed (r=−0.74, p<0.01). We demonstrated that circadian activity was not directly related to exercise capacity, despite the difference regarding exercise capacity and thermoregulation at two different circadian periods of rat activity. Supported by: CNPq and FAPEMIG