Effect of the body fat status of female students aged 17-19 years, engaged in aerobics, on the thermoregulation system during cooling

Abstract

The purpose of the article is to study the effect of moderate cooling at an ambient temperature of 20-21 °C on maintaining the homeostatic balance of the skin in aerobics students of the three comparison groups with different fat status. Materials and methods. After a standard 15-minute warm-up the signal was recorded in aerobics students aged 17-19 years with a BALTECH TR-01500 thermal imager (Germany). Recording was performed from the entire surface of the body in the infrared frequency range for 10 minutes. Depending on the percentage of adipose tissue in the body (AT), which was determined using the Tanita BC - 418 MA analyzer (Japan), the subjects were divided into three comparison groups with the following average AT values: 22.31 ± 0.23% (values between 20-25%; group 1, n1 = 21), 16.11 ± 0.46% (values between 15-20%; group 2, n2 = 16), 30.89 ± 0.78% (values more than 25 %; group 3, n3 = 14). Results: according to average values of the temperature of the skin located above the regions of the examined muscles, Microsoft Excel built graphs of the changes in the average skin temperature of the students of the three groups according to the data registered every 30 seconds. The dynamics of temperature curves of all studied muscle groups for the left and right part of the body (abdominal muscle, deltoid muscle, biceps, triceps, trapezius, latissimus dorsi, biceps femoris, quadriceps femoris, anterior tibia, gastrocnemius muscle) was almost identical for the three examination groups, except for trapezius. The slight differentiation of the manifestations of non-contractile thermogenesis among the students of group I throughout the entire exposure to cooling kept the temperature of the skin at almost the same level (the temperature range was 0.8 ° C). Students of the second and third groups, starting from the first session of thermography, showed an abrupt change in average temperature, significantly different from the temperature curve of the first group. Discussion and conclusions: the strategy of maintaining thermal balance allowed the system of thermoregulation in the first group to effectively control the temperature homeostasis of the muscles actively involved in sports movements, indicating better adaptation to moderate cooling, which is one of the necessary conditions for the effectiveness of muscle activity. In students of the second and third groups, skin temperature fluctuations during exposure to cold reached 1.8 °C, which was explained by the functional insufficiency of the adaptive thermoregulatory systems due to excessive ergothermal load on the adaptive capabilities of the body.