Boston Celtics head coach Joe Mazzulla says that he loves BJJ – despite being regularly getting beaten on the mats.

Speaking on the Champion Mindset podcast, Mazzulla explained that most sessions leave him discouraged, and that’s precisely the point:

I would say like 60% of the time I leave the mats, I’m like crushed emotionally.
I’m like just discouraged, disheartened, like just got my butt kicked, but I need that.

For Mazzulla, the sport serves a purpose beyond fitness, too:

I can go a whole season and have zero physical stress on my body. The players have physical, mental, and emotional stress.
So if I can be in the arena with them by training and I can almost act as a player, I can empathise where they’re at on particular days.

The BJJ blue belt described a parallel between earning his promotion and winning the 2024 NBA championship:

I had the same feeling the day I got promoted to my blue belt as I did when we won the championship.

That mindset traces back to Mazzulla’s upbringing in Rhode Island, where his father instilled physical and mental toughness early on, reinforced later by a college coach who built an environment where fear was channeled into competitive drive.

As a head coach himself, Mazzulla recognized how easy it becomes to lose that edge once leadership allows someone to direct others without facing the same scrutiny.
And, well, Jiu-Jitsu became his answer to that problem:

You need something that exposes yourself to yourself.
You need to feel what it’s like to be disheartened. Feel what it’s like to be discouraged.

Sloth Jiu-Jitsu: The Ultimate Guide for Calmly Beating Bigger, Younger Opponents

💥 What if slowing down was the fastest way to win? 💭 Tired of Getting Smashed by Younger, Stronger Grapplers? It’s not your age. It’s your strategy. If you’re a passionate grappler over 35 who’s sick of getting outpaced, outmuscled, or out-cardio’d by opponents half your age — this 120 page e-book was made for you. 🔓 Unlock the Power of Sloth Jiu-Jitsu:

Build Sustainable Strength—Without Wrecking Your Joints, Energy, or Jiu-Jitsu

Tired of waking up sore and burnt out after lifting? Sloth Strength is a proven blueprint for grapplers over 35 who want to get stronger—without the pain, burnout, or injuries.

Developed from 25 years on the mats, this no-burnout approach is made specifically for BJJ athletes in their 30s, 40s, and beyond.