Aerobic Metabolic Adaptations in Endurance Eccentric Exercise and Training: From Whole Body to Mitochondria.
Level 5 - mechanism / opinion, no new human data
Narrative review summarizing human and animal literature
PubMed 33584331 · doi:10.3389/fphys.2020.596351
What was done
The authors reviewed published human and animal studies assessing aerobic metabolic adaptations to endurance eccentric exercise (specifically eccentric cycling and downhill running). The review examined components of the oxygen transport system across systemic oxygen consumption, peripheral vascular distribution, and cellular markers of mitochondrial biogenesis and respiration.
What was found
No specific numbers or effect sizes are provided in the abstract. The reviewed evidence indicates that the aerobic demand of eccentric training is generally too low to significantly increase peak maximal oxygen consumption (VO2peak), likely because the power outputs required to drive central aerobic adaptations are unsustainable or intolerable. Additionally, training did not demonstrate an impact on skeletal muscle mitochondrial respiration or selected mitochondrial mRNA transcripts, and data on peripheral flow distribution remain largely undocumented.
Why it matters
This review clarifies that despite substantial benefits for muscle mass and strength at low cardiopulmonary strain, endurance eccentric exercise alone appears inadequate to drive central cardiorespiratory or mitochondrial aerobic adaptations.
Limits
The abstract describes a narrative review without reporting study counts, sample sizes, or quantitative pooled estimates. Much of the mechanistic mitochondrial data relies heavily on animal models, and peripheral flow distribution remains largely undocumented.
Cited by
- supports Downhill running is an eccentric form of aerobic training.