Introduction and Purpose: The effects of different types of resistance exercise (RE) on hematological markers involved in anemia have remained understudied. Therefore, this study characterized the effects of three types of RE on hematological markers.

Materials and Methods: Ten resistance-trained women (age 26.30±4.95 years, body mass index 22.07±2.02 kg/m2) were recruited and completed hypertrophy- (3×10-12 repetitions with 70% of one repetition maximum [1-RM]), strength- (7×3-5 repetitions with 90 % of 1-RM), and power-type (5×4 repetitions with 40 % of 1-RM) RE at eight stations. Venous blood was sampled before and immediately after each trial. Within-group differences were assessed by dependent t-student and Wilcoxon tests. In addition, between-group differences were examined using an analysis of covariance test.

Results: Power-type RE caused a significant decline in hemoglobin (P=0.007), mean corpuscular hemoglobin (P=0.018), and mean corpuscular hemoglobin concentration (P=0.043). Strength-type RE significantly reduced the mean corpuscular hemoglobin (P=0.045). Lymphocyte count significantly reduced following strength- (P=0.045) and power-type RE (P=0.004). However, higher levels of platelet counts (P=0.014) and plateletcrit (P=0.006) were observed in hypertrophy-type than in power-type RE. The hemoglobin level was significantly lower after the power-type RF than hypertrophy-type RE (P=0.023). Moreover, a lower level of mean corpuscular hemoglobin was observed in strength-type relative to hypertrophy-type RE (P=0.018).

Discussion and Conclusion: Hypertrophy-type RE had no adverse effects on hematological parameters. However, hematological markers involved in anemia declined following strength-type and power-type RE. Taken together, coaches should monitor hematological markers in athletes performing high-intensity strength or power training to prevent anemia-related performance decrements.