Marathon performance is influenced by factors such as aerobic capacity and those related to neuromuscular function. Complex training (CPX) is a multicomponent training method, wherein heavy strength and plyometric exercises alternate within a single session and is an effective method to improve neuromuscular adaptations. This study compared the effects of CPX, heavy strength training (HST) and endurance-strength (EST) combined with running endurance training on neuromuscular adaptations and running performance in 38 recreational marathoners (age:31.4 ± 3.8 years, VO2max:57.6 ± 6.8 ml·kg-1·min-1). Athletes were allocated in 3 groups: CPX, HST and EST and were tested for one maximum repetition strength (1RM), squat jump and countermovement jumps (SJ, CMJ), leg press (LP) concentric and eccentric strength, running economy (RE) and velocity at VO2max (vVO2max) before and after the 6-week intervention. CPX and HST were performed 2 times per week in conjunction with the running endurance training. RE and vVO2max improved in CPX and HST groups (p < 0.01, RE: -5% to -6.4%, vVO2max: 5.7% and 4.2%, respectively) with no change in EST. Similarly, all neuromuscular performance indicators improved in CPX and HST (p < 0.0167, 1RM strength:19.7% to 25.1%, SJ and CMJ: 5.3% to 11.6%, LP concentric and eccentric strength: 5.5% to 18.0%). In summary, 6-week of concurrent CPX or HST and endurance training resulted in similar improvement in maximum strength, RE, and vVO2max. Importantly, both CPX and HST training resulted in greater improvements in eccentric strength and RE compared to EST that performed concurrent endurance-strength and endurance training.
Keywords: Complex training; endurance training; heavy strength training; neuromuscular adaptation; running economy.