A new review from the National Institute on Aging introduces the Oxygenaging framework, detailing how oxygen delivery and utilization impact endurance athletes.
On August 28, 2026, the journal Aging Cell published an open access review titled “Oxygenaging: A Physiological Framework for Geroscience.” The paper was authored by Stefano Donega, Luigi Ferrucci, and several colleagues. The researchers are primarily affiliated with the U.S. National Institute on Aging and the University of Calgary. They propose a physiological model that directly links systemic oxygen transport to the biology of aging.
The authors define Oxygenaging as the progressive loss of equilibrium and resilience across the oxygen cascade. This framework argues that age related oxygen dysfunction actively contributes to molecular damage and functional decline over time. The paper presents oxygen biology as a connecting lens. This lens allows researchers to understand multiple aging processes together.
These processes include vascular decline, mitochondrial dysfunction, redox imbalance, and the loss of functional reserve. The primary conclusion of the review focuses on the complex journey of oxygen through the human body. This oxygen cascade describes the process of moving oxygen from the atmosphere to the lungs, bloodstream, and cardiovascular system. From there, it must reach the microvasculature, target tissues, and finally the mitochondria.
The central thesis is that oxygen delivery must continuously match changing metabolic demand. The research demonstrates that this critical coordination becomes steadily less effective with advancing age. The review identifies age related changes at several specific physiological levels. These include less efficient pulmonary gas exchange, reduced cardiac reserve, microvascular rarefaction, and endothelial dysfunction.
At the cellular level, the authors note impaired mitochondrial electron transfer efficiency and increased electron leakage. They also note altered oxygen sensing and weaker cellular quality control responses. The review categorizes these into three broad problems. The first is direct impairment of the oxygen cascade.
The second problem involves microvascular dysfunction. The third is molecular maladaptation in oxygen sensing and stress response systems. The authors connect Oxygenaging with several established mechanisms of cellular decline. These mechanisms include mitochondrial dysfunction, oxidative stress, iron dyshomeostasis, and ferroptosis.
They also highlight links to epigenetic remodeling, cellular senescence, and impaired cellular resilience. The paper emphasizes that the oxygen cascade is a highly coupled system. Impaired pulmonary or cardiovascular delivery can increase overall tissue stress. Similarly, impaired microvascular diffusion or mitochondrial utilization can worsen the mismatch between oxygen supply and demand.
The review explicitly states that Oxygenaging is a conceptual framework rather than a newly validated clinical diagnosis. It does not replace the established hallmarks of aging, nor does it claim oxygen dysfunction is the single primary cause of aging. Instead, it describes complex interactions among oxygen transport, tissue availability, and cellular resilience. The authors stress that the evidence base remains somewhat fragmented.
The exact relative contributions of oxygen delivery, mitochondrial content, and impaired oxygen utilization are still under investigation. To support this framework, the review synthesizes measurements from numerous clinical and physiological studies. The paper reports that maximal oxygen uptake, or VO2max, falls by approximately 10 percent per decade. The authors also describe an approximate 15 to 20 mmHg decline in arterial oxygen tension between mid life and older age.
Furthermore, the review states that maximal heart rate may decline by approximately 25 percent. The authors use an illustrative comparison of about 200 beats per minute in youth versus 150 beats per minute in older age to demonstrate this cardiac reserve loss. The research highlights measurable changes in how tissues receive and utilize oxygen. The paper reports that ventilation perfusion heterogeneity, measured by SDQ, rises from approximately 0.36 in younger people to 0.47 in older people.
In the cited data, resting frontal regional cerebral oxygen saturation declined from approximately 69.8 percent in young adults to 62.7 percent in older adults. A cited prospective study reported median cerebral oxygen saturation values of 67 percent among people aged 18 to 49. These median values dropped to 63 percent among those aged 50 to 74. Finally, they fell to 60 percent among those aged 75 or older.
The authors note that the reported cerebral oxygenation measurements require careful interpretation. Near infrared spectroscopy detects a composite arterial and venous signal and can include scalp contributions. However, muscle recovery metrics also show distinct age related shifts in oxygen kinetics. Cited measurements showed post exercise phosphocreatine recovery of approximately 37 seconds in young muscle.
In aged muscle, this recovery time extended to 52 seconds. This indicates a significantly slower recovery of oxidative energy metabolism in the older group. For the ambitious endurance athlete over 35, this framework fundamentally changes how we approach training, recovery, and longevity. It is common to view aging performance strictly as a loss of muscle strength or aerobic volume.
The Oxygenaging paper supports a shift away from that narrow perspective. Oxygen delivery, tissue diffusion, mitochondrial utilization, and recovery kinetics are deeply interdependent components. Older adults have slower muscle reoxygenation after exercise, lower resting muscle perfusion, and lower oxidative capacity than younger adults. Athletes must begin treating recovery capacity as a systemic oxygen utilization issue.
The most defensible takeaway is to protect your entire oxygen cascade through sustainable aerobic training. The review reports that regular physical activity is associated with better ventilatory function, cardiovascular performance, and microvascular density. It also improves endothelial health and mitochondrial oxidative capacity. Conversely, chronic inactivity is associated with the exact opposite pattern.
The paper describes exercise induced increases in temperature and local acidity as contributors to the Bohr effect. This effect helps shift the hemoglobin oxygen dissociation curve and facilitates oxygen unloading to working tissues. Maintaining this aerobic foundation helps preserve the body's ability to regulate oxygen delivery under changing demand. You can review how structured training models apply these concepts by examining an endurance training by decade framework.
Building long term physical resilience remains a central pillar of the science of active aging for endurance athletes. Focusing on sustainable cardiovascular health protects your baseline performance. This is why consistent cardiovascular screening is a practical priority for older athletes. The review also evaluates interventions like intermittent hypoxia and hyperbaric oxygen therapy.
Some meta analyses found VO2max improvements with intermittent hypoxic training. However, parallel design comparisons against normoxic training found no clear advantage. The authors attribute these conflicting results to differences in exposure duration, minimum inspired oxygen concentration, protocol design, and participant characteristics. They also cite research where daily intermittent hypoxia improved walking speed in people with motor incomplete spinal cord injury.
This finding applies to rehabilitation science and should not be generalized automatically to healthy masters athletes. Therapeutic intermittent hypoxia involves controlled, low dose exposure with planned reoxygenation. The authors explicitly state this should not be confused with obstructive sleep apnea, which causes uncontrolled oxygen cycling and sleep fragmentation. Even so, the therapeutic window for healthy older adults remains unestablished.
Interventions sit within a narrow boundary between beneficial stress and injury. The authors warn that this therapeutic window may narrow with age. This narrowing is due to reduced cardiopulmonary reserve, reduced antioxidant capacity, and expanded labile iron pools. Older adults also face multimorbidity, frailty, and greater susceptibility to oxidative stress.
Hyperbaric oxygen carries similar clinical caveats. The review describes a proposed hyperoxic hypoxic paradox. In this paradox, exposure to high oxygen followed by a return toward normal levels may trigger adaptive signaling. The paper cites a small prospective study reporting increased telomere length in immune cell subsets following hyperbaric oxygen therapy.
However, the authors note that the study lacked a randomized sham control and does not establish broad biological rejuvenation. The authors call for larger randomized controlled trials stratified by frailty status. They also suggest individualized monitoring of oxidative stress and mitochondrial function. Integrating these findings logically is part of maintaining metabolic health and endurance training.
Hyperbaric oxygen should be viewed as investigational for healthy athletes seeking longevity. The strongest actionable message is not to use more oxygen, but to preserve your body's ability to regulate it.
Endurance athletes should prioritize sustainable aerobic training to protect their systemic oxygen delivery, treating experimental hyperbaric or hypoxic therapies with caution until clinical evidence matures.
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