Knowing when to train and how much time to devote to training each of the three energy systems is an important ingredient of success in endurance sports. This knowledge is also reflected in a well-designed and scientifically-based training plan.

In this session from the 2015 NSCA National Conference, Nelson Ayotte—the Strength and Conditioning Coach for the St. Louis Blues National Hockey League (NHL) team—explains how to design and implement a specific energy systems program at the elite level. Ayotte demonstrates the characteristics of each of the three energy systems and their trainability, and explores how to understand the energy demands of a sport by analysis of its characteristics, competition intensity, and duration of efforts and recovery periods.

In this session from the 2017 Coaches Conference, Joe Eisenmann explains the three major energy systems in the human body, identifies appropriate tests of physical work capacity, and explains how to design programs that maximize energy production and fatigue resistance in sports.

In this session from the 2015 NSCA Coaches Conference, Cal Dietz, MS, presents the best applications in training of several sports that can be applied to most sports at various times of the year. The systematic approaches and the reasoning behind the step-by-step approach to block training, and the application of specific needs in the sport and energy system training also are covered.

In this 2018 coaches conference video Todd Hamer describes his experience working with collegiate football players, and his methods for targeting appropriate energy systems to increase athletic performance in speed and conditioning.

This excerpt briefly describes the different energy systems used by structural and wildland firefighters.

This excerpt from NSCA's Essentials of Tactical Strength and Conditioning aims to educate on some fundamentals of energy systems training in tactical personnel.

In order to effectively prepare an ice hockey player for the season, it is necessary to have a thorough understanding of the specific demands of the sport.

This article explains Fartlek training as well as how it can be programmed and individualized for different clients.

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.