Portland Trail Blazers forward Moe Harkless had a busy off-season.

The former St. John's star spent the summer working out at the IMG Academy in Florida, training to build off his career-best 2016-17 season, where he set highs in all major statistical categories.

Harkless kept an intense routine, spending most days doing two sessions of weight training in the morning, and two more sessions of basketball-related workouts at night.

“It basically was four different workouts every day,” Harkless told Men’s Fitness. “Deadlifts are my favorite, and I love pullups—I could do pullups all day. I really love lunges, too. Those are really effective. I try and mix things up in my routine.”

But no matter what workout Harkless is doing, he always makes sure to keep focus on his core strength.

“Keeping your core and legs strong is key,” Harkless says. “I do a lot of planks, I use them as a warmup in the weight room before I start my routine. I’ll do a five-minute plank series using front-planks, side-planks, planks with one arm up, all kinds. Planks and using kettlebell workouts are my favorite way to do core stuff. Kettlebell squats are one of the best ways to hit those areas."

Here’s a look at the core workout that Harkless uses to stay in shape.