Some athletes are motivated by anger — but the rest of us shouldn't follow their lead

And for many of them, it can be downright motivational.

For instance, here's NBA star Isaiah Thomas talking about how he uses slights from others as motivation to get better to ESPN in June:

"My mental edge is being counted out, being doubted. If you've ever been doubted in your life, you want to prove people wrong. So that's what I always wanted to do. I've been doubted every step of the way.

"I use every little bit of negativity as motivation to keep getting better and to show people what I'm capable of doing."

He's not alone. Many athletes believe anger helps them perform better.

But while professional athletes are at the top of their field, it doesn't mean everything they do is worth imitating in pursuit of success. Discipline? Yes. Workout schedule? Maybe. Angry grudges? No.

Anger is a double-edged sword

Even among athletes, the relationship between anger and performance is unclear. For example, a 2011 study on high-level karate athletes found that although anger helped some of them in certain situations by giving them more energy, in other cases it hurt them, leading them to use their energy ineffectively.

Further, most people (non-athletes) have to be even more careful with anger. Even if it can be conducive to physical activities, it's much less so for mental ones.

Psychologist Roger S. Gil explains to Lifehacker that though channeling anger can be effective, "[i]t helps when the activity that needs to get done is physical (i.e. requiring you to use your hands or body) since anger tends to speed us up. It's important not to do anything that requires too much thought since our minds are likely going to be clouded by the anger and we will not be able to make sound choices."

While anger is not necessarily always a bad thing, it's clear that we have to be careful in when, and how, we use it.

Grudges are unproductive and unhealthy

And that's just talking about anger. A grudge is a different animal — a persistent anger you hold over perceived slights for a prolonged period of time.

Holding a grudge has been shown to be very detrimental for productivity and health.

TalentSmart founder Travis Bradberry notes that focusing attention on past events that angered you "create and prolong negative emotions and stress, which hinders performance."

Further, holding a grudge allows the initial feelings of anger to fester, eventually leading to resentment and thoughts of revenge. All these negative emotions can block you from feeling happiness. Instead of holding a grudge, consider practicing forgiveness instead, which has been shown to lead to less stress and significantly better mental and physical health.

It can be tempting, even exciting, to relish in anger, picturing ourselves getting revenge on the people that we think wronged us. The reality, however, is that you may just be hurting yourself.