1.
The August Krogh Institute: Capillaries and beyond.
Sjøgaard, G
Scandinavian journal of medicine & science in sports. 2015;:16-21
Abstract
Bengt Saltin knew very well the history and work of the giants whose shoulders he was standing upon, such as August Krogh and Johannes Lindhard. He was basically a physiologist interested in physical activity and exercise, particularly in the cardiovascular and muscular responses. Some of his major original contributions were (a) the human muscle model in terms of the one-legged, knee extensor quantifying work by the high-precision Krogh ergometer and, using this, challenging Krogh's proposed autoregulation of capillary blood flow during exercise; (b) the electrolyte fluxes quantification on an intra- and extra-cellular level in human muscle during exercise to reveal such changes as possible fatigue mechanisms; and (c) the evidence presented that underlined the health-enhancing effect of physical exercise training from bedside to workplace.
2.
Impact of diet and exercise on lipid management in the modern era.
Franklin, BA, Durstine, JL, Roberts, CK, Barnard, RJ
Best practice & research. Clinical endocrinology & metabolism. 2014;(3):405-21
Abstract
Unfortunately, many patients as well as the medical community, continue to rely on coronary revascularization procedures and cardioprotective medications as a first-line strategy to stabilize or favorably modify established risk factors and the course of coronary artery disease. However, these therapies do not address the root of the problem, that is, the most proximal risk factors for heart disease, including unhealthy dietary practices, physical inactivity, and cigarette smoking. We argue that more emphasis must be placed on novel approaches to embrace current primary and secondary prevention guidelines, which requires attacking conventional risk factors and their underlying environmental causes. The impact of lifestyle on the risk of cardiovascular disease has been well established in clinical trials, but these results are often overlooked and underemphasized. Considerable data also strongly support the role of lifestyle intervention to improve glucose and insulin homeostasis, as well as physical inactivity and/or low aerobic fitness. Accordingly, intensive diet and exercise interventions can be highly effective in facilitating coronary risk reduction, complementing and enhancing medications, and in some instances, even outperforming drug therapy.
3.
Performance in the heat-physiological factors of importance for hyperthermia-induced fatigue.
Nybo, L, Rasmussen, P, Sawka, MN
Comprehensive Physiology. 2014;(2):657-89
Abstract
This article presents a historical overview and an up-to-date review of hyperthermia-induced fatigue during exercise in the heat. Exercise in the heat is associated with a thermoregulatory burden which mediates cardiovascular challenges and influence the cerebral function, increase the pulmonary ventilation, and alter muscle metabolism; which all potentially may contribute to fatigue and impair the ability to sustain power output during aerobic exercise. For maximal intensity exercise, the performance impairment is clearly influenced by cardiovascular limitations to simultaneously support thermoregulation and oxygen delivery to the active skeletal muscle. In contrast, during submaximal intensity exercise at a fixed intensity, muscle blood flow and oxygen consumption remain unchanged and the potential influence from cardiovascular stressing and/or high skin temperature is not related to decreased oxygen delivery to the skeletal muscles. Regardless, performance is markedly deteriorated and exercise-induced hyperthermia is associated with central fatigue as indicated by impaired ability to sustain maximal muscle activation during sustained contractions. The central fatigue appears to be influenced by neurotransmitter activity of the dopaminergic system, but inhibitory signals from thermoreceptors arising secondary to the elevated core, muscle and skin temperatures and augmented afferent feedback from the increased ventilation and the cardiovascular stressing (perhaps baroreceptor sensing of blood pressure stability) and metabolic alterations within the skeletal muscles are likely all factors of importance for afferent feedback to mediate hyperthermia-induced fatigue during submaximal intensity exercise. Taking all the potential factors into account, we propose an integrative model that may help understanding the interplay among factors, but also acknowledging that the influence from a given factor depends on the exercise hyperthermia situation.