Siim Land: What Happens To Your Body After 70 Days In Bed?

Key Takeaways

• Prioritize daily movement – Even short periods of inactivity cause rapid declines in muscle (23% loss in 70 days), bone density (1-3% loss), and aerobic fitness (10% VO2 drop).
• Exercise counters inactivity damage – NASA participants who trained horizontally (treadmill, cycling, resistance work) preserved fitness despite bed rest.
• Combat insulin resistance – Inactivity spiked HOMA-IR to prediabetic levels (1.74 → 2.24). Regular movement is non-negotiable for metabolic health.
• Target soleus/calf muscles – This muscle atrophied fastest (0.33% daily). Include heel raises and weighted leg work.
• Rebound quickly after inactivity – Detraining effects outpace aging (70 days = ~10 years of muscle/function loss). Resume activity ASAP.

Notable Quotes

“Movement is not optional, it’s the signal that tells your body to be stronger, fitter, and younger. Use it or lose it.”

Bottom Line

Move daily – even minimal activity prevents catastrophic declines in muscle, bone, and metabolic health. Prioritize resistance training and weight-bearing exercise.

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