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Adaptations of skeletal muscle mitochondria to exercise training
Author(s) -
Lundby Carsten,
Jacobs Robert A.
Publication year - 2015
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/ep085319
Subject(s) - endurance training , mitochondrion , vo2 max , mitochondrial biogenesis , skeletal muscle , interval training , respiration , citrate synthase , medicine , exercise physiology , endocrinology , biology , physical medicine and rehabilitation , physical therapy , anatomy , biochemistry , heart rate , enzyme , blood pressure
New FindingsWhat is the topic of this review? We review recent work relating to exercise‐induced alterations in mitochondrial structure and function.What advances does it highlight? Training mitochondrial volume density increases due to 1) an increase cross sectional area and 2) longitudinal growth. Specific respiratory alterations appear dependent on exercise training intensity. Low‐moderate endurance training primarily improves the capacity for fat oxidation whereas high‐intensity interval training (HIT) improves global respiratory capacity. The latter includes maximal state 3 mass‐specific respiration, which is the strongest individual measure predictive of endurance performance. This highlights the importance of training specificity in endurance athletes.Mitochondrial volume density (Mito VD ) is composed of two distinct mitochondrial subpopulations— intermyofibrillar mitochondria (Mito IMF ) and subsarcolemmal mitochondria (Mito SS ). With exercise training, Mito VD may increase by up to 40% and is, for the most part, related to an increase in Mito IMF . Exercise‐induced adaptations in mitochondrial function depend on the intensity of training and appear to be explained predominately by an increased expression of mitochondrial enzymes that facilitate aerobic metabolism. Although mitochondrial content often increases with training, it seems that mitochondrial adaptations are not needed to facilitate maximal oxygen uptake, whereas such adaptations are of greater importance for endurance capacity.