Saeid Yazdanirad, Habibollah Dehghan, Mohammad Zeinodini, Yaser Rahimi,
Volume 13, Issue 3 (10-2017)
Abstract
Background: The Heat Strain Scoring Index (HSSI) is one of the indexes used for evaluating heat strain. The present study was carried out to determine the relationship between HSSI and heart rate in overweight and obese individuals during light and moderate intensity exercise under warm laboratory conditions.Methods: This experimental study was carried out on 35 individuals with normal weight (BMI < 25) and 35 overweight and obese participants (BMI > 25) in a climatic chamber. Each participant was asked to rest. Then, each participant underwent a 60 minute light intensity activity (2.8 kph on a treadmill) while exposed to hot climatic conditions (37 °C). In the next phase, the participants were asked to rest for 30 minutes, and then, undergo a 60 minute moderate activity (4.8 kph on a treadmill) while exposed to warm climatic conditions (32 °C). The participants’ heart rate was measured every 2 minutes. The HSSI questionnaire was completed during the rest, after the first and second 25 minutes of activity.Findings: The Pearson correlation coefficients showed a linear and direct relationship between the HSSI score and heart rate of the first activity (r = 0.50, P < 0.001) and the HSSI score and heart rate of the second activity (r = 0.64, P < 0.001) under the warm climatic conditions. Moreover, the results showed a linear and direct relationship between the HSSI score and heart rate of the first activity (r = 0.47, P < 0.001) and the HSSI score and heart rate of the second activity (r = 0.64, P < 0.001) under the hot climatic conditions.Conclusion: Based on the results of this study, the mean heart rate and mean HSSI score were higher in overweight and obese participants than those with normal weight. Furthermore, there was a significant correlation between heart rate and HSSI.