Mitochondria as the Cellular Foundation of Movement: Why the Condition of the Cell’s “Power Plants” Determines Physical Performance with Aging
Abstract
With aging, the decline in strength, endurance, and mobility is not caused only by a reduction in muscle mass. One of the key factors is the loss of the muscle cells’ ability to efficiently produce energy.
In this review, Cummings, Coen, and Ferrucci analyze data from the Study of Muscle, Mobility and Aging (SOMMA) — one of the largest studies investigating the cellular mechanisms underlying muscle aging. The analysis included 879 individuals aged 70 years and older. Researchers examined biopsies of the vastus lateralis muscle and assessed the condition of mitochondria — intracellular structures responsible for energy production.
The authors found a strong association between the maximum capacity of mitochondria for oxidative phosphorylation (maximal mitochondrial oxidative phosphorylation, maxOXPHOS) and physical performance.
Participants with higher mitochondrial capacity demonstrated greater muscle power, better cardiorespiratory endurance, and faster 400-meter walk times. In contrast, reduced mitochondrial energy-producing capacity was associated with increased fatigability and physical frailty, although no direct association with fall risk was identified.
The study also shows that age-related decline in muscle function is associated with multiple cellular changes, including accumulation of oxidative damage to proteins, reduced antioxidant defense capacity (particularly the SOD2 enzyme), impaired autophagy and mitophagy processes, and deterioration of neuromuscular connections.
The authors conclude that mitochondrial bioenergetics is one of the key cellular determinants of maintaining strength, endurance, and mobility in older age.
Conclusions
This study is important because it demonstrates that physical performance depends not only on the amount of muscle tissue but also on the functional quality of the cells that make up the muscle.
Mitochondria are the primary energy-producing structures in muscle cells. Their ability to efficiently use oxygen for ATP production is directly associated with strength, endurance, and preservation of mobility. When mitochondrial function declines, cells produce less energy, fatigue more rapidly, and become more vulnerable to age-related changes.
In the context of hypoxic-hypercapnic training, this work is important because it highlights mitochondria as one of the major cellular systems involved in adaptation. Controlled exposure to hypoxia and hypercapnia creates a metabolic signal that is detected by cells and may activate processes responsible for mitochondrial renewal and optimization.
A key component of this adaptation is mitochondrial quality control: the removal of old and damaged mitochondria through mitophagy and the stimulation of new mitochondrial formation through mitochondrial biogenesis. These processes can improve energy metabolism efficiency, enhance cellular oxygen utilization, increase energy production, and reduce excessive generation of reactive oxygen species (ROS).
Therefore, adaptation to hypoxic-hypercapnic exposure is associated not only with improved oxygen delivery to tissues but also with an increased ability of cells to efficiently utilize oxygen within mitochondria.
However, it is important to note that this publication analyzes the relationship between mitochondrial function and physical performance in older adults and does not directly investigate the effects of hypoxic-hypercapnic training. Its significance lies in demonstrating that mitochondrial function is a central factor determining physical capacity and in explaining why interventions aimed at improving cellular energy metabolism may be important for maintaining muscle function.
Full bibliographic information
Cummings SR, Coen PM, Ferrucci L. The cellular bases of mobility from the Study of Muscle, Mobility and Aging (SOMMA). Aging Cell. 2024;23(6):e14129.
DOI: 10.1111/acel.14129
PMID: 38429931
