The purpose of this article is to help both personal trainers and clients with seven main concepts within exercise physiology that will improve training effectiveness and assist in explaining the body’s response to exercise.

This article discusses the importance and impact a qualified fitness professional on the fitness and readiness of soldiers for the United States Army.

This article summarizes current populations and descriptions of sedentariness and deconditioning, and offers practical considerations for personal trainers working with these behaviors.

A client asks you about melatonin, are you prepared to answer? This article explores the efficacy and safety of supplemental melatonin as a sleep aid in adults.

This article reviews electromyography (EMG) procedures as well as provides examples of how EMG data analysis has been used in tactical populations.

Tom Williams’ journey to Head of Performance and Sport Science for Major League Soccer (MLS) powerhouse, the Los Angeles (LA) Galaxy, began at a crossroads: pursue traditional coaching or medical pathways. As a soccer “Swiss Army knife,” he embraced early sport science alongside coaching, building a career defined by collaboration and innovation. At the Galaxy, Williams is part of a web of support that uses rich data storytelling tailored to stakeholders and players, guiding decisions and infusing value in every encounter. This system drives their three key pillars: winning championships — including their recent record-breaking sixth MLS Cup — developing a robust academy pipeline, and leading innovation. In MLS’s “cultural melting pot,” Williams balances diverse backgrounds and short-term demands like fixture congestion while employing sustainable long-term strategies. With a unique full-time cognitive department and creative approaches like dodgeball warm-ups, he combines trust and ingenuity to elevate performance and presents a blueprint for those exploring emerging sport science. Reach out to Tom on LinkedIn: @tom-williams and X/Twitter: @Williams26Tom | Find Eric on Instagram: @ericmcmahoncscs and LinkedIn: @ericmcmahoncscs Did you know MLS has a newly mandated Certified Performance and Sport Scientist® (CPSS®) role? Engage with NSCA’s Pro Sport Partner, the Professional Soccer Performance Association (PSPA), on social media to learn more: Instagram: @pspa_performance X/Twitter: @PSPA_perform LinkedIn: @professional-soccer-performance-association

In this career series article, developing personal training skills to train special populations is discussed; it includes starting out as a novice through the expert level.

The VO2max test is the most effective measurement of the body’s ability to deliver and use oxygen for producing energy that can be used by the muscles. VO2max (i.e., maximum aerobic power) simply stands for the maximal volume of oxygen that can be used.

Tactical facilitators are especially well-positioned to integrate mental skills training that may develop more complete tactical athletes who are prepared for dangerous environments. This article offers recommendations for mental skills training based on reported views from a tactical population.