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.

The TSAC-F Online Practice Questions help candidates become familiar with the type, scope, and difficulty of the questions on the TSAC-F Certification exam. The questions assist in developing a better understanding of the content and help to assess relative strengths and weaknesses.

Sprinting is a key component for many individual and team sports. Therefore, to enhance sprint performance, various training methods are widely used by coaches and practitioners, including maximum sprint speed and resisted sprint training. Resisted sprinting with sled towing is a method that has recently received considerable attention from the sport science community. However, to date, no consensus exists regarding its acute and chronic effects in team sport athletes. This narrative review aimed to (a) review and analyze the mechanics of sprinting under unresisted and resisted conditions with a specific focus on team sport disciplines; (b) provide a thorough and applied discussion on the importance of considering acute and chronic effects of sled loading on technique, electromyographic activity, and force production, as well as on the role of muscle architecture and neural factors in sled training; (c) analyze the effects of increasing sled loads during acceleration and maximum velocity phases on contact and flight phases, while concomitantly examining kinetic, kinematic, and neuromuscular aspects, because all these factors affect each other and cannot be properly understood in isolation.

Agility is a key and complex concept within team sports performance. Because of its multidimensional nature, agility benefits from perceptual and cognitive skills as well as physical capacity (e.g., ability to exert acceleration, deceleration, and changes of direction). Agility should be integrated in different and complementary ways in team sports training. From more analytical to more ecological tasks, there is a need to comprehend the respective adaptations and identify how to integrate such a spectrum and, eventually, combine them in the training process and manage it accordingly to the player’s needs. Based on this premise, the purpose of this article is to present alternative methods and recommendations that may help to develop agility in field-based invasion sports. The main concepts pertaining to agility and associated capacities will be explored. Afterward, a proposal for a more analytical approach based on the use of cones and ladders will be introduced, as well as approaches based on small-sided games. Finally, an integration of agility training and a combination of approaches will be presented using soccer as an example.

NSCA Coach provides valuable takeaways for every level of strength and conditioning coach through quarterly, electronic issues. You can find scientifically based articles specific to a wide variety of your athletes’ needs with Nutrition, Programming, and Youth columns.