The 4-Hour Body

The 4-Hour Body collects Tim Ferriss’s experiments across fat loss, strength, endurance, sleep, and other aspects of physical performance. It is a foundational biohacking text because it treats the body as a system to measure and iterate, but its personal experiments and aggressive claims need independent verification.

The book is built around self-experiments, mixed evidence quality, and broad claims; do not treat anecdotes or small samples as clinical evidence.