Abstract
John O. Holloszy, as perhaps the world’s preeminent exercise biochemist/physiologist, published >400 papers over his 50+ year career, and they have been cited >41,000 times. In 1965 Holloszy showed for the first time that exercise training in rodents resulted in a doubling of skeletal muscle mitochondria, ushering in a very active era of skeletal muscle plasticity research. He subsequently went on to describe the consequences of and the mechanisms underlying these adaptations. Holloszy was first to show that muscle contractions increase muscle glucose transport independent of insulin, and he studied the mechanisms underlying this response throughout his career. He published important papers assessing the impact of training on glucose and insulin metabolism in healthy and diseased humans. Holloszy was at the forefront of rodent studies of caloric restriction and longevity in the 1980s, following these studies with important cross-sectional and longitudinal caloric restriction studies in humans. Holloszy was influential in the discipline of cardiovascular physiology, showing that older healthy and diseased populations could still elicit beneficial cardiovascular adaptations with exercise training. Holloszy and his group made important contributions to exercise physiology on the effects of training on numerous metabolic, hormonal, and cardiovascular adaptations. Holloszy’s outstanding productivity was made possible by his mentoring of ~100 postdoctoral fellows and substantial NIH grant funding over his entire career. Many of these fellows have also played critical roles in the exercise physiology/biochemistry discipline. Thus it is clear that exercise biochemistry and physiology will be influenced by John Holloszy for numerous years to come.
Highlights
The last 50 years has seen dramatic advances in the fields of exercise biochemistry and exercise physiology, and a substantial number of these advances have come from the laboratories of Dr John Holloszy, who spent virtually his entire academic career at Washington University School of Medicine in St.Louis, MO
In a 1973 study the Holloszy group demonstrated that the various skeletal muscle fiber types differentially expressed glycolytic enzymes [6]. These enzymes were affected differently by endurance exercise training, with the slow-type fibers increasing their glycolytic capacity while the opposite occurred in the fast-white and fast-red muscle types. These findings collectively demonstrated a pattern of adaptation such that endurance-trained skeletal muscle took on properties more similar to those of cardiac muscle, which represents the epitome of endurance-trained muscle
Keith Baar in the Holloszy group found that transgenic mice overexpressing the transcription factor nuclear respiratory factor 1 (NRF-1) were characterized by increased muscle expression of MEF2A and GLUT4, as well as a greater capacity for insulin-stimulated glucose uptake [4]
Summary
The last 50 years has seen dramatic advances in the fields of exercise biochemistry and exercise physiology, and a substantial number of these advances have come from the laboratories of Dr John Holloszy, who spent virtually his entire academic career at Washington University School of Medicine in St. Keith Baar in the Holloszy group found that transgenic mice overexpressing the transcription factor nuclear respiratory factor 1 (NRF-1) were characterized by increased muscle expression of MEF2A and GLUT4, as well as a greater capacity for insulin-stimulated glucose uptake [4] He subsequently reported that a single prolonged exercise session (2 bouts of 3 h separated by 45 min rest) resulted in greater NRF1 and NRF2 protein abundance at either 12 or 18 h postexercise [3]. His research was instrumental in establishing that increased GLUT4 protein abundance in skeletal muscle is a hallmark of chronic exercise, and a series of studies from his laboratory made significant contributions to the current understanding of the molecular processes responsible for this adaptation His discoveries using animal models paved the way for his laboratory’s important research on the effects of exercise on glucose metabolism in humans. This follow-up study demonstrated for the first time that the beneficial effects of intensive initial training can be preserved for long periods in motivated patients who continue to exercise
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Schedule a callMore From: Journal of applied physiology (Bethesda, Md. : 1985)
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