Homeostasis Theory in Human Movement: Seeking Safety in Movement Dysfunction

Kurt Hester, Head of Sports Performance at Louisiana Tech University, talks to the NSCA Head Strength and Conditioning Coach, Scott Caulfield, about his journey from weight lifting at 12 years old to training collegiate football athletes today. Topics under discussion include starting a business, pioneering strength and conditioning, and the interview process. Find Kurt on Twitter: @thekurthester or on Instagram: @hesterkurt | Find Scott on Instagram: @coachcaulfield

This Kinetic Select from NSCA’s Essentials of Personal Training, Second Edition gives a brief overview of respiratory adaptations, and how aerobic interventions of duration and intensity can be used for specific adaptations for endurance training.

The physiological response to breath holding includes bradycardia and peripheral vasoconstriction, which contrasts with that of exercise which includes tachycardia and peripheral vasodilation. This raises the question as to what the physiological response is to breath holding during exercise. During low-intensity exercise, the breath holding response of bradycardia and peripheral vasoconstriction prevails over the exercise response of tachycardia and peripheral vasodilation, but nevertheless the exercise may be sustained. Due to the lack of availability of extrinsic oxygen (O 2 ) from the atmosphere during breath holding, the energy demands can be met by increased reliance on intrinsic O 2 stores (i.e., O 2 that was in the body before the breath hold) via increased O 2 extraction at the muscle compared with exercise while breathing, or increased contributions from anaerobic energy systems. During high intensity exercise of short duration, the exercise response may prevail over the breath holding response due to the increased parasympathetic withdrawal and sympathetic drive of higher intensity exercise. If breath holding during high-intensity exercise was sustained for long enough, the breath holding response may eventually overcome the exercise response, although this may be difficult due to the inverse relationship between exercise intensity and breath hold duration.

This article presents two football-specific speed drills in detail—the single-leg box explosion and the mountain climber.

PT 2022

This article provides a firsthand account with knowledge and advice for personal trainers looking to start and grow their business.

You don’t have to love the weight room, but you can’t last without it. Champ Bailey, a National Football League (NFL) Hall of Famer, admits he never enjoyed lifting, but says respecting the work gave him the edge to sustain 15 seasons at the highest level. Hear how his preparation evolved from traditional lifts to readiness routines — core, mobility, warm-ups, and recovery — that kept him fresh through the NFL grind. Bailey emphasizes that strength and conditioning coaches are undervalued leaders who “see you at all levels,” guide comebacks, and build buy-in with simple numbers. He recalls how a failed conditioning test led to one of his best seasons, and how weight room leadership left no cracks to ensure buy-in from everyone. Bailey continues his impact through the Positive Athlete initiative, using sport as a platform for growth. Gain practical ways to tailor training by role, earn athlete respect, and build a winning culture. Connect with Champ via email at: ChampBailey@positiveathlete.org | Find Eric on Instagram: @ericmcmahoncscs and LinkedIn: @ericmcmahoncscs Answer the call to give back and lead the profession. Applications for the NSCA and NSCA Foundation Boards of Directors are now open, with more volunteer positions available October 1. See if you qualify and apply at NSCA.com/Volunteer.

This research review covers topics such as the effects of police officer equipment loads, military occupational specialties, and the effects of protective clothing and self-contained breathing apparatus for firefighters.

Review assessment protocols for military personnel, firefighters, and police officers from NSCA’s Essentials of Tactical Strength and Conditioning, 2nd Edition.