Exercise physiology is the study of the acute responses and chronic adaptations to a wide range of physical exercise conditions. In addition, many exercise physiologists study the effect of exercise on pathology, and the mechanisms by which exercise can reduce or reverse disease progression. Accreditation programs exist with professional bodies in most developed countries, ensuring the quality and consistency of education. In Canada, one may obtain the professional certification title - Certified Exercise Physiologist for those working with clients (both clinical and non clinical) in the health and fitness industry.
An exercise physiologist's area of study may include but is not limited to biochemistry, bioenergetics, cardiopulmonary function, hematology, biomechanics, skeletal muscle physiology, neuroendocrine function, and central and peripheral nervous system function. Furthermore, exercise physiologists range from basic scientists, to clinical researchers, to clinicians, to sports trainers.
Since their discovery, anabolic steroids (AAS) have been widely used as an ergogenic aid to improve performance in sports, to improve one's physical appearance, as self-medication to recover from injury, and as an anti-aging aid. Use of anabolic steroids for purposes other than treating medical conditions is controversial and, in some cases, illegal. Major sports organizations have moved to ban the use of anabolic steroids. There is a wide range of health concerns for users. Legislation in many countries restricts and criminalizes AAS possession and trade. A political counter current has formed in some of these countries.]citation needed[.
Performance-enhancing substances have been used for thousands of years in traditional medicine by societies around the world, with the aim of promoting vitality and strength. The use of gonadal hormones pre-dates their identification and isolation. Medical use of testicle extract began in the late 19th century, while its effects on strength were still being studied. In 1889, the 72-year-old French neurologist Charles-Édouard Brown-Séquard injected himself with an extract of dog and guinea pig testicles, and reported at a scientific meeting that these injections had led to a variety of beneficial effects. However, almost all experts, including some of Brown-Sequard's contemporaries, had agreed that these positive effects were induced by Brown-Séquard himself. In 2002, a study replicating Brown-Séquard's method determined that the amount of testosterone obtained was too low to have any clinical effect.
Pen needles are used in conjunction with injection pens to deliver injectable medications into the body.
A pen needle consists of a hollow needle which is embedded in a plastic hub and attaches to injection pens. Pen needles come in a variety of needle lengths and diameters and are used by both health professionals and patients for injection of a variety of medications. They are commonly used by people with diabetes who often require multiple daily insulin injections.