Response of Some Hematologic Factors to Single Session of CrossFit Exercise in Professional Male Athletes

Background: High-intensity exercise is one of the effective factors in hematologic changes. Objectives: The purpose of this study was to determine the effects of a single session of CrossFit exercise on platelets (Plts), red blood cells (RBCs), white blood cells (WBCs), hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) in professional male athletes. Methods: Thirty-two male athletes were selected as subjects (with mean age 26.9 ± 4.7 years, height 177 ± 5 cm, weight 80.7 ± 6.4 kg). The CrossFit exercise session consisted of running for 400 meters, three-stage deadlifting, pull-up (30 repetitions), 30 kg kettlebell swinging, and throwing 20 sand balls. Blood sampling and CBC tests were used to measure hematologic indices. The biochemistry auto analyzer also was used to measure lactate as a witness variable. In addition, ANOVA with repeated measures and Bonferroni post hoc tests were used to examine the differences between variables in resting position, post-exercise, and after correction for the volume of plasma lost. Results: The results of the present study showed a significant increase in lactate, Plts, and WBCs (P < 0.0001). However, there were significant decreases in RBCs, Hct, Hb, MCV, MCH, and MCHC (P < 0.0001). Conclusions: A single session of CrossFit exercise causes disorder in hematologic responses of professional male athletes. So, it is recommended to have enough time to recover after this type of exercise.