Overview
- Professor Michelle Spear of the University of Bristol synthesizes evidence showing that small physiological shifts converge in midlife as responsibilities intensify.
- Skeletal muscle begins to decline from the late 30s unless maintained with resistance training, making everyday activity require more energy.
- Cellular energy production becomes less efficient in the 40s, so late nights or stress exact a larger recovery cost than in early adulthood.
- Sleep grows more fragmented due to hormonal variability, including perimenopausal changes, with a greater chance of nighttime cortisol rises that reduce restorative rest.
- The analysis emphasizes modifiable steps—regular sleep timing, strength training, stress management, and adequate protein—with many people reporting more stable energy in their 60s.