While the concept of homeostasis is to maintain a stable internal environment, Allostasis which theorized later after Cannon (1929) by Sterling (2004) as the alternative extension model to homeostasis.
Allostasis
Allostasis is the body dynamic active process of adapting stressors, allowing for dynamic regulation around different set points as needed.
Allostatic balance often equate to the dynamic adaptation during exercise. It reference to the body dynamic responses to navigate complex challenging environments. For example the body support the adaptation to stimuli such as increasing load and time of exercise. While homeostasis emphasize the act of returning the system to baseline, the allostasis process anticipate the needs to change and modulating physiological reactions ahead of the actual demand.
Adaptive Environment:
Temperature Regulation: Athletes physiology modifying set points when adapting to challenging climates or prolonged physical activities.
pH Balance: Adjusting pH levels dynamically during intense exercise as lactic acid builds up, enabling sustained physical performance.
Glucose Concentration: Shifting glucose availability through glycogen mobilization and insulin sensitivity adjustments during prolonged exercise or fasting.
Oxygen and Carbon Dioxide Levels: Adapting respiratory functions during high-altitude exposure to ensure efficient oxygen uptake and carbon dioxide expulsion.
Adaptive Processes:
Thermoregulation: Enhancing circulatory efficiency and sweat gland adaptation for better heat dissipation.
Metabolic Pathway: The body switches between the 3 primary energy systems ( Phoshagen ATP-PCr, Anaerobic Glycolysis, Aerobic) depending on the type of exercise and its intensity and duration.
Cellular Respiration: Boosting mitochondrial density and function to increase ATP under exercise stressor.
Anticipation and Adaptation
Under Allostasis, fluctuation and perturbation refers to triggers that drive adaptive response to long-term balance.
Temperature: Body adjusting metabolic rate and cardiovascular responses to anticipate repeat exposure to cold or heat.
Dietary Changes: Modulating metabolism and hormone release in response to nutrient availability to maintain energy balance and electrolyte homeostasis.
Stress: Enhancing the HPA (Hypothalamic-pituitary-adrenal) axis to better manage exercise or environmental stress, and promoting resilience.
Physical Activity: recomposition of musculoskeletal structure ( muscle hypertophy, bone density) and improvement in cardiovascular capacity in response to exercise intensity and volume.
Allostasis maintains a dynamic, adaptable internal environment, enabling the body to thrive amid ever-evolving demands and stressors. In conclusion, Allostasis and Homeostasis are compatible and complimentary components of physiological regulation.
