A book by a friend of ours, Nassim Nicholas Taleb.
It begins with:
"Some things benefit from shocks; they thrive and grow when exposed to volatility, randomness, disorder, and stressors and love adventure, risk, and uncertainty. Yet, in spite of the ubiquity of the phenomenon, there is no word for the exact opposite of fragile. Let us call it antifragile. Antifragility is beyond resilience or robustness. The resilient resists shocks and stays the same; the antifragile gets better"
A great description of why it is so important to resistance train with barbells. We recommend this paperback book to many of our clients.