Effects of Interval and Power Training on the Physical, Physiological, and Training Characteristics of Trained Distance Runners
Authors: Mesfen Arefayne , Melkamu Zelalm 
Published: November 2024

Background: Previous research has individually investigated how different types of training affect the physical, physiological, and training characteristics of distance runners. However, there is a lack of studies that collectively examine the effects of interval and power training programs on these factors in trained distance runners. Objectives: This study aims to provide a more comprehensive and up-to-date understanding of how combined training approaches may impact the physical, physiological, and training characteristics of competitive distance runners. Methods: A census sampling approach was used, with all 108 athletes (100%) participating in the study. Participants were divided into three parallel training groups: The interval training group (ITG), the power training group (PTG), and the control training group (CTG). Each group contained 36 participants, and a randomized block design was implemented within each group, with 12 athletes in each block. The intervention lasted for 32 weeks, with three training sessions per week, on non-consecutive days, lasting 45 - 60 minutes per session. The intensity of the training sessions was maintained between 50 - 70% of the participants' exercise capacity. The measured physical characteristics included demographic and anthropometric variables such as age, sex, height, weight, Body Mass Index (BMI), fat and fat-free mass, and various circumferences. The physiological characteristics assessed included resting heart rate, exercise heart rate, maximum oxygen consumption, measures of leg strength (LS) and power, endurance performance metrics such as time trials (TTs), and aerobic thresholds. The training characteristics assessed included living and training altitude, training habits, training experience, training volume, training sessions, recovery practices, and nutritional intake. Statistical significance was determined with a P-value of < 0.05, and effect size was calculated (η² > 0.14). Results: Interval and power training led to improvements in several physical characteristics, including chronological age (P = 0.02), Body Mass Index (P = 0.03), fat-free mass (P = 0.000), and maximum thigh circumference (P = 0.000). However, no significant changes were observed in certain physical characteristics such as sex, field, and weight (P = 1.000). Interval and power training also resulted in significant improvements in various physiological characteristics, including 400 m sprint performance (P = 0.000), 1.5 km Kosmin test (P = 0.000), 3 km maximum speed TT (P = 0.000), LS (P = 0.000), Sprint Bounding Index (SBI) (P = 0.000), and maximum exercise heart rate (P = 0.000). In contrast, the post-test (POT) results for the ITG and PTG groups, when compared to the CTG, showed no significant differences in certain areas of physiological characteristics, including Balke V̇O2Max (P = 0.000), leg press (P = 0.000), and squat (p = 0.000). Regarding the third subgroup analysis of training characteristics, all POT results showed a decrease, except for the habit of sleeping (P = 0.04). In general, the POT results of the CTG demonstrated less change in all subgroup analyses of performance indices compared to the ITG and PTG. Conclusions: Our key findings emphasize the importance of combined interval and power training in improving V̇O2Max, overall strength endurance, speed endurance, running economy (RE), and muscle adaptation compared to the control group. These factors are vital for enhancing physical and physiological characteristics. Future research should explore additional factors, such as nutrition and psychological needs, which may influence athletic performance.