ABSTRACT
             Background and Objectives: Apolipoprotein M (APOM) is a novel high-density lipoprotein (HDL)-associated protein involved in the production of pre-beta HDL and cholesterol efflux to HDL. The present study examined effect of 12 weeks of aerobic interval training on HDL-associated APOM levels.
             Methods: Study population included 20 healthy men aged 20 to 24 years. The subjects were randomly and equally divided into a training group and a control group. Each training session included 10 minutes of warm-up, 35 minutes of aerobic training (5 combined cycles each including four minutes of running at intensity of 85-95% and an active resting period of treadmill running at 65-75% of maximum heart rate for 3 minutes) and 10 minutes of cool-down. Blood samples (10 mL) were taken every four weeks. Two-way ANOVA and Bonferroni's post hoc test were used to compare the groups. A P-value of less than 0.05 was considered statistically significant.
             Results: At the end of the 12^th week, HDL-associated APOM levels increased in the training group and decreased in the control group. However, these changes were not statistically significant (P>0.05). 
             Conclusion: This study demonstrated that the 12-week aerobic interval training does not significantly affect HDL-associated APOM levels. However, it is recommended to monitor subjects’ diet throughout the study period to reach a more comprehensive conclusion. 
             Keywords: Aerobic interval training, Apolipoprotein M, Young men.

ABSTRACT
             Background and Objectives: Apolipoprotein O (apoO) is a 198 amino acids protein that exists predominantly in high-density lipoprotein (HDL). It may exert cardioprotective effects via decreasing fat accumulation and increasing removal of cholesterol from macrophages. Although the health benefits of exercise are well documented, no study has yet investigated the effects of various types of training, including resistance training on apoO level. Therefore, we aimed to determine effects of five weeks of circuit resistance training with different intensities on plasma levels of apoO, HDL, total cholesterol (TC) and triglyceride (TG) in young untrained men.
             Methods: Forty-five age- and weight-matched healthy untrained men were randomly assigned to a control group (n=10) and four training groups: training at 20% intensity (n=9), training at 40% intensity (n=8), training at 60% intensity (n=7) and training at 80% intensity (n=8). The subjects performed circuit resistance training at 10 stations (30 seconds at each station) with three repetitions, without rest between stations and with 3-minute active rest between the repetitions. The training was carried out for 45 minutes per session, three sessions a week, for five weeks. Venous blood samples were taken 48 hours before the first exercise session and 48 hours after the last training session. Plasma levels of apoO, HDL, TC and TG were measured using commercial kits. Data were analyzed using repeated measures ANOVA and Tukey's post hoc test at significance level of 0.05.
             Results: After the training intervention, mean plasma level of TC and TG did not differ significantly between the study groups (P>0.05). Training at 80% of one-repetition maximum (1RM) caused a slight decrease in the apoO concentrations. Moreover, apoO concentration was significantly higher in the 20% 1RM training group compared to other study groups (F=11.599, P<0.002).
             Conclusion: Our results indicate that circuit resistance training at 80% of 1RM can decrease HDL-associated apoO level but does not significantly alter other parameters.
             KEYWORDS: Circuit resistance training, HDL-O, TC, TG, Young men.