"I'm a recovering workaholic," admits Jullien Gordon, a nationally recognized speaker and founding partner of New Higher, on his website.
Workaholism, he says in a 2014 LinkedIn post, looks similar to high performance on the outside--but they're actually nothing alike.
Gordon spent years doing research and conducting experiments on himself to understand the difference between workaholism and high performance.
He found that while they both look like hard work, "the big difference is how the individual feels on the inside about who they are in [relation] to their work," he explains.
A high performer works hard in "healthy sustainable ways and feels happy and inspired," he adds. Meanwhile, a workaholic "works hard in unhealthy unsustainable ways and feels unhappy and burned out." 
Here are three more subtle differences between workaholics and high performers: