Does the Repeated-Bout Effect Influence Post-Activation Performance Enhancement in Recreational Runners?

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanics

Background:

• The repeated-bout effect (RBE) describes the protective response of muscles to prior exercise, reducing subsequent muscle damage.
• Post-activation performance enhancement (PAPE) is a temporary increase in muscle force production following a conditioning contraction.
• Understanding how low-dose exercises influence RBE and PAPE is crucial for optimizing training protocols in recreational runners.

Purpose of the Study:

• To investigate if a low-dose eccentric-oriented lunge exercise can induce the repeated-bout effect (RBE) in recreational runners.
• To determine the impact of this RBE on subsequent post-activation performance enhancement (PAPE).
• To assess the effects on jump capacity, dynamic balance, and running kinematics.

Main Methods:

• Twenty male recreational runners were divided into control and experimental groups.
• The experimental group performed two sessions of eccentric lunges (3 sets of 10 reps) separated by two weeks.
• Jump capacity, dynamic balance, and running kinematics were measured before and after an incremental shuttle-run test.

Main Results:

• The first eccentric lunge session induced muscle damage, which was significantly reduced in the second session, confirming an RBE.
• No significant effects of RBE were observed on dynamic balance or submaximal running kinematics post-intervention.
• A significant increase in countermovement jump height was noted in the experimental group, but PAPE was not observed.

Conclusions:

• A simple, low-dose eccentric lunge exercise can induce an RBE, leading to reduced muscle damage in recreational runners.
• The induced RBE may enhance lower limb muscle power, as indicated by improved jump height.
• The RBE did not appear to directly influence the potentiation/fatigue balance, as PAPE was absent after fatiguing running.