Exercise training and 3-day head down bed rest deconditioning: exercise thermoregulation

• Autorzy: Smorawinski J. , Mlynarczyk C. , Ziemba A.W. , Mikulski T. , Cybulski G. , Grucza R. , Nazar K. , Kaciuba-Uscilko H. , Greenleaf J.E.
• Języki publikacji: EN

Abstrakty

EN

Bed rest (BR) deconditioning causes excessive increase of exercise core body tempera-ture, while aerobic training improves exercise thermoregulation. The study was designed to determine whether 3 days of 6° head-down bed rest (HDBR) affects body temperature and sweating dynamics during exercise and, if so, whether endurance training before HDBR modifies these responses. Twelve healthy men (20.7±0.9 yrs, VO2max: 46±4 ml·kg-1·min-1) underwent HDBR twice: before and after 6 weeks of endurance training. Before and after HDBR, the subjects performed 45 min sitting cycle exercise at the same workload equal to 60% of VO2max determined before training. During exercise the VO2, HR, tympanic (Ttymp) and skin (Tsk) temperatures were recorded; sweating dynamics was assayed from a ventilated capsule on chest. Training increased VO2max by 12.1% (p<0.001). Resting Ttymp increased only after first HDBR (by 0.22 ± 0.08 °C, p<0.05), while exercise equilibrium levels of Ttymp were increased (p<0.05) by 0.21 ± 0.07 and 0.26 ± 0.08 °C after first and second HDBR, respectively. Exercise mean Tsk tended to be lower after both HDBR periods. Total sweat loss and time-course of sweating responses were similar in all exercise tests. The sweating threshold related to Ttymp was elevated (p<0.05) only after first HDBR. In conclusion: six-week training regimen prevents HDBR-induced elevation of core temperature (Ttymp) at rest but not during ex-ercise. The post-HDBR increases of Ttymp without changes in sweating rate and the tendency for lower Tsk suggest an early (<3d) influence of BR on skin blood flow.

Słowa kluczowe

EN

microgravity; head down bed rest; thermoregulation; aerobic training; skin temperature; bed rest; sweating rate; core temperature

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2005
• Tom: 56
• Numer: 1
• Opis fizyczny: p.101-110,fig.,ref.

Twórcy

autor

Smorawinski J.

• Academy of Physical Education, Poznan, Poland

autor

Mlynarczyk C.

autor

Ziemba A.W.

autor

Mikulski T.

autor

Cybulski G.

autor

Grucza R.

autor

Nazar K.

autor

Kaciuba-Uscilko H.

autor

Greenleaf J.E.