iron will: unyielding chain of resilience. concept strength training, mental toughness, resilience

iron unyielding chain resilience strength determination endurance perseverance tenacity courage fortitude persistence grit backbone steadfastness resolve toughness indomitable unbreakable unwavering steely robustness stalwart solidity resolute spirit firmness bravery boldness fearlessness dauntlessness valor mettle steel rocksolid aigenerated