Effects of training modalities on physiology, hematology, and performance in elite Ethiopian distance male athletes

This study aimed to investigate the physiological, hematological, and performance adaptations resulting from sequential blocks of endurance (EnT), speed (SpT), and strength (StT) training in elite Ethiopian middle- and long-distance male runners. Using a quasi-experimental repeated-measures design with a fixed order (EnT → StT → SpT), twenty male athletes (23.7 ± 3.2 years; 3000–10000 m events) completed three 6-week training blocks. Physiological (estimated VO₂max, resting heart rate, running economy), hematological (hemoglobin, hematocrit, Red blood cell count (RBC), White blood cell count (WBC)), and performance measures (400 m speed, 5000 m time trial, 12-minute Cooper test) were assessed pre- and post-intervention using paired T-tests and repeated-measures ANOVA. The endurance training block produced significant improvements in aerobic and hematological parameters, including estimated VO₂max (+ 6.20 ml·kg⁻¹·min⁻¹), resting heart rate (− 3.80 bpm), and hematocrit (+ 4.35%) (all p < 0.001). Subsequent strength and speed training blocks were associated with gains in running economy (StT: −4.2% oxygen cost, p < 0.01; SpT: −1.8%, p < 0.05) and 400 m speed (StT: −1.21 s, SpT: −1.00 s; both p < 0.001). All training modalities contributed to improved 5000 m times (EnT: −18 s, p < 0.01; SpT: −9 s, p < 0.01; StT: −6 s; p < 0.05). The sequential training approach resulted in complementary improvements across aerobic, anaerobic, and neuromuscular domains.