Physiological responses to cold (10° C) in men after six months' practice of yoga exercises

Abstract

A study was conducted on 30 healthy soldiers (age: 40–46 years) to assess the effect of selected yogic exercises (asanas) on some physiological responses to cold exposure. They were randomly divided into two groups of 15 each. One group performed regular physical exercises of physical training (PT), while the other group practised yogic exercises. At the end of 6 months of training, both the groups were exposed together to cold stress at 10°C for 2 h, and the following parameters were periodically monitored during cold exposure: heart rate (fH), blood pressure (BP), cardiac output$(\dot Q_c )$, oral temperature (T_or), skin temperature (T _sk), respiratory rate (fR), minute ventilation$(\dot V_E )$, oxygen consumption$(\dot V_{O_2 } )$, and shivering response by integrated electromyogram (EMG). There were progressive increases inBP, fR,$\dot V_E$,$\dot V_{O_2 }$, and$\dot Q_c$ and decreases infH,T _or andT _sk during cold exposure in both the groups. However, the decrease inT _or and the increases in$\dot V_{O_2 }$ and$\dot V_E$ were relatively lower (P<0.01) in the yoga group as compared to the PT group. The shivering response appeared much earlier and was more intense in the PT group. These findings suggest that practice of yoga exercises may improve cold tolerance.