Training and immune system

Moderate, appropriately balanced training can support immune function, while prolonged intense exercise and inadequate recovery can suppress it.

• 60 minutes of brisk walking: Daily brisk walking for about 60 minutes is associated with increased T-cell function, natural-killer-cell activity, and macrophage function. 1
• Sessions of 60 minutes or less: Moderate-to-high-intensity exercise lasting 60 minutes or less can increase the circulation and activity of innate immune components for many hours—possibly up to 24 hours. Shorter workouts may also help: the discussion notes benefits from as little as 12 minutes, provided the effort is very intense. 2 3
• Prolonged intense exercise: After marathon-level exertion, T-cell function and natural-killer-cell activity can fall substantially, while stress hormones and inflammatory molecules rise. 4
• Overexertion and recovery: Huberman describes sleep deprivation and pushing exercise too hard or too long as patterns that preceded bouts of illness for him; he emphasizes moderation and avoiding inadequate recovery. 5 Sleep deprivation can also impair innate immune function. 6
• If you start feeling sick: For a minor sniffle, consider shortening the workout, reducing endurance intensity, doing fewer weight-training sets, and avoiding sets to failure. If you feel genuinely ill or have whole-body malaise, the guidance is to rest rather than train intensely. 7 8