What do we Know about Complex-Contrast Training? A Systematic Scoping Review.

Area of Science:

• Sports Science and Exercise Physiology
• Neuromuscular Adaptation
• Training Methodology

Background:

• Complex-contrast training (CCT) involves alternating high-load/low-velocity and low-load/high-velocity exercises within sets.
• The proposed mechanism for CCT is post-activation potentiation or performance enhancement (PAPE), improving subsequent high-velocity movements.
• Existing literature lacks systematic synthesis on CCT's effectiveness and PAPE measurement during training.

Purpose of the Study:

• To systematically review and synthesize the existing evidence on complex-contrast training (CCT).
• To identify research gaps in CCT implementation and outcomes using an evidence gap map (EGM).
• To provide future research directions for optimizing CCT protocols.

Main Methods:

• A systematic scoping review was conducted using PubMed, Scopus, and Web of Science databases up to February 20, 2024.
• Data extraction followed a PICO framework, focusing on participants, intervention duration, comparators, and performance outcomes.
• Interactive evidence gap maps (EGMs) were generated using EPPI mapper software.

Main Results:

• Sixty-eight studies involving 1,821 participants (145 females) were included; interventions lasted ≤16 weeks.
• Countermovement jump, sprint, and maximal strength were the most frequently assessed outcomes.
• No studies examined upper-body-only CCT or assessed PAPE during training sessions; overall evidence confidence was low.

Conclusions:

• The capacity of CCT to induce PAPE that leads to sustained performance improvements remains uncertain.
• Low confidence in current evidence hinders definitive conclusions on optimal CCT implementation, especially for females and long-term effects.
• Significant gaps exist in understanding CCT's efficacy across diverse populations and training durations.