Acceleration and maximum speed are terms used in speed development programs, and when developing a program, it is vital to differentiate between the two. This allows coaches to target their training to the capacity most important in their own sport.

The purpose of this article is to provide an introduction to contrast training, including how it is defined, what variables are utilized, and examples of how to use it in training.

Considering the great popularity of eccentric-based training, the purpose of this review is to first provide the scientific rationale for its use; second, summarize the eccentric-based training modalities that can be used; and finally, offer practical recommendations on how to implement eccentricbased modalities to enhance sports performance. The molecular and neural mechanisms underlying eccentric actions are partially distinct from those of concentric and isometric actions. During eccentric actions, theories suggest a strain-induced modulation of actin-myosin interactions at the crossbridge level, activation of structural protein titin, and winding of titin on actin. Eccentric acute physiological responses differ from concentric exercise responses, including variations in neuromuscular, metabolic, hormonal, and anabolic signaling. Eccentric training elicits greater improvements in muscle strength, power, and stretch-shortening cycle function compared with concentric-only or traditional resistance training. Therefore, eccentric-based training can lead to unique neuromuscular (e.g., improved coordination of motor units) and morphological (e.g., increased muscle fascicle length and enhanced distal cross-sectional area) adaptations that could play a key role in sport performance. Practitioners may implement eccentric exercises with external loads, fully eccentric-based exercises (e.g., Nordic hamstring curl), accentuated eccentric loading, flywheel resistance exercise, and plyometrics to develop specific physical adaptations in line with their goals. Eccentric work (e.g., for hamstrings) can be obtained during other exercises such as downhill running tasks, decelerations, and sprinting activities. Practitioners need to be aware that no single “silver bullet” training modality exists; consequently, practitioners should use a combination of eccentric-based training approaches with their athletes to obtain the desired adaptations.

This article is part of a continuing series of tactical strength and conditioning (TSAC) research reviews. It is designed to bring awareness to new research findings of relevance to tactical strength and conditioning communities.

Physical assessments have evolved as a result of developments in scientific research, equipment loads, operational environments, and doctrine.

The aim of this article is to provide those working with tactical populations an introduction into tracking training load to mitigate injury risk while concurrently optimizing fitness.

This article examines how training the core and performance are connected. This article seeks to help propose how to best use the literature to maximize understanding and use of the current concepts.

This article sets out to address and dispel these myths, offering evidence-based insights into the significance, safety, and multifaceted benefits of strength training for youth.