When Harriet Anderson crossed the finish line at Kona — the Ford Ironman World Championship — in October 2009, there were a few reasons she stood out.

At 74 years of age, she was the oldest female competitor to complete the race. At 11:53 p.m. she finished, just seven minutes before the cutoff. And the reason she’d taken longer than usual?

The arm taped to her side was a clue. She’d broken her clavicle at mile 80 of the bike ride when another cyclist bumped into her. Did that deter Harriet? No. She picked herself up, finished the next 32 miles on the bike, and promptly walked the entire 26.2 miles of the marathon.

You can power through the 2.4-mile swim in ocean water. You can jump on your 27-speed carbon bicycle to ram through 112 miles of hot, dry pavement. Finally, you slip into a pair of shorts for a 26.2-mile marathon. Thousands begin the race and many fail to make the finish.  In 2013, at the age of 78, no one else could match her “Wonder Woman” power to cross the finish line—first in her age group.

Running an Ironman breaks most men down to physical misery and exhaustion. To do what she does at age 53 all the way to 78 defies our imagination. If you are a man or woman, look her story up on the Internet. She will motivate you, cause a sense of awe in you and bring out the best in your body, mind and spirit.

Endurance sports are not about finding your limits; they’re about finding out what lies beyond them. For Harriet Anderson, she lives with no limits.