The effect of interval recovery periods during HIIT on liver enzymes and lipid profile in overweight women

Background. High-intensity interval training programs are one of the effective means to improve lipid profiles. It has been claimed that the amount of some of the enzymes are indicative of the normal functioning of liver. The purpose of this research is to examine the effects of different recovery intervals different rest intervals during the High-intensity interval training programs on liver enzymes and serum lipid levels of overweight women. Methodology. Twenty-four volunteer women with mean aged 34.42 +/- 5.3 years old with BMI 29.48 +/- 3.45 kg/m(2), weight of 80 +/- 0.08, height of 159.14 +/- 4.60 cm, respectively were randomly assigned into three equal groups (n=8) of 60/60 activity-rest, 60/30 activity-rest and control. The exercise protocol included 4 weeks of 4 trials, three sessions per week at 80% reserved heart rate increased to 10 trials in the fourth week. Results. Four weeks of HIIT sessions did not result in significant change in blood lipid profiles including HDL-C, HDL/LDL, cholesterol, TG, and liver enzymes (ALP, AST, and ALP) in addition to body composition (P < 0.05). There was a significant difference in the percentage of fat in the three groups (P < 0.05). In addition, there was a significant inverse association between the liver enzymes and HDL-C (P < 0.05). Conclusion. Based on the result of this research, 4 weeks of HIIT activities result in no significant change in indices of blood lipids as well as liver enzymes. However, a considerable change was observed in the body fat percent that may be attributed to the exercise protocol. (C) 2014 Published by Elsevier Masson SAS.