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 discusses the ratings of perceived exertion (RPE) scales and how to educate older clients to utilize them, as well as how to monitor and safely progress their training intensity.

This article reviews the use of heart rate as a way to program cardiovascular exercise.

The purpose of this article is to discuss the health and occupational implications of firefighters not currently meeting the National Fire Protection Association (NFPA) aerobic capacity recommendations.

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

The loading intensity a person chooses depends on his or her goals and training status (i.e., whether the person is a trained athlete or a sedentary individual). Ultimately, the number of repetitions you can perform at a given intensity or load determines the effects of training on strength develop.

The 3-minute all-out exercise test (3MT) was developed over a decade ago and enables the estimation of time for onset of momentary fatigue for a given speed or power output exceeding critical speed (CS) or critical power (CP), respectively. The 3MT has been validated for conducting high-intensity interval training, used with load carriage prediction and prescription, and validated for shuttle running. These prescriptions are novel because they allow for standardizing exercise intensities relative to metabolic parameters as opposed to a percentage of a given maximum or reserve. Research was identified using leading search engines (e.g., PubMed, Google Scholar, and Research Gate) and citations to similar articles. The objective of this review article was to summarize research that emerged on the CS/CP concept with emphasis on applications since the advent of the 3MT. The review concludes with application of the CS/CP concept to the frequency, intensity, time, and type of exercise for exercise prescription.

The goal of this brief review is to describe what classifies as high-intensity interval training (HIIT) and summarize the potential benefits for various populations: athletic, general, and clinical.

This article from NSCA Coach explores how beet juice and nitrate supplements can enhance athletic performance. Learn more about nutrition and exercise physiology online at NSCA.com.

High-intensity strength training paired with explosive, high-velocity movements is suggested to enhance endurance performance. It is recommended that a practical approach be taken when implementing this model of strength training, which would involve a thorough preparatory period.