This article serves to educate strength and conditioning coaches on the influence exercise can have on the various hormonal pathways that are impacted by polycystic ovarian syndrome (PCOS), including insulin resistance, cortisol, testosterone, follicle-stimulating, and luteinizing hormones.

The catecholamines—primarily epinephrine, but also norepinephrine and dopamine—are secreted by the adrenal medulla and are important for the acute expression of strength and power because the hormones act as central motor stimulators and peripheral vascular dilators to enhance enzyme systems and calcium release in muscle.

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 will examine the physical demands of soccer players and discuss why repeated sprint ability (RSA) is considered highly important in the performance of these athletes.

This column will explore specific investigations that evaluate the impact of PA and fitness on mental and physical health outcomes among firefighters and law enforcement officers.

With the average investment for personal training being $200 per client per month, professional personal trainers have the potential to earn over $100,000 a year if they apply themselves appropriately.

Trainer Tips are infographics designed to help you, an NSCA professional, educate clients and promote your services. These member-only resources can be used for client education, motivation, and promotion.

Through a well-designed resistance training program, firefighter recruits can gain the movement skills, confidence to exercise, and foundational strength/physiological adaptations that they need for a long and healthy career.

This article features the recharge skate—an in-season hockey conditioning drill, designed by the authors, to maintain hockey-specific energy system fitness throughout the competitive season.

This excerpt from NSCA’s Essentials of Sport Science highlights the importance of quantifying training load for both programming and monitoring an athlete’s progression or regression over time.