Hemoglobin, hematocrit and plasma volume variations following combined sprint and strength: effect of advanced age

Objectives: The study investigated the effect of combined sprint and resistance training (CSRT) on red blood cell (RBC) count, hemoglobin (Hb), hematocrit (Hct), plasma volume (PV) variation at rest and during exercise. Equipment and methods: Twenty-eight moderately trained were randomly assigned into a young trained (YT), young control (YC), middle-aged trained (MAT), and middle-aged control (MAC) group. Before (P1), and after (P2) CSRT, blood samples were collected at rest and after exercise. Results: At P1, Hct was significantly (P <.05) greater in young compared to middle-aged groups. At P1, PV decrease during exercise was significantly (P <.05) higher in middle-aged compared to young groups. Following CSRT, resting RBC count and Hb increased significantly (P<.05) in MAT. At P2, Following CSRT, Hct decreased significantly (P<.05) in trained groups. At P2, no significant (P >.05) age-effect between MAT and YT was observed for Hct. Conclusion: CSRT increases RBC count and Hb in middle-aged men, and ameliorates the effect of age in Hct. Such adaptations may improve cardiovascular fitness of middle-aged individuals, and may be preventative of subsequent declines with age.