If you have an Instagram account., then we’re willing to bet that the face (and absdelts and quads) of Eric Leija has graced your 6.5-inch screen before. The Onnit coach, aka @primal.swoldier, is known for performing quick-hitting and dynamic kettlebell routines for his 500,000 followers. But before he was repping #Onnit and #PrimalSwoldierOpens in a new Window. on the gram and coaching hundreds of clients at the Onnit gym, he was packing boxes for the Texas-based fitness company as a warehouse employee. 

“Then Aubrey Marcus, the CEO, was like, ‘Hey, we should open up a gym so that we can show people how to use all of these unconventional tools,” Leija says.   

In addition to selling supplements, Onnit also hucks a variety of “functional” equipment, from kettlebells to more enigmatic tools. like Indian clubs and steel maces. Leija, who was in pretty good shape and trained mixed martial arts, had experience with kettlebells, so he decided to get certified and begin teaching classes.  

“It was the IKFF [International Kettlebell and Fitness Federation] certification, taught by Ken Blackburn,” Leija explains. I learned how to do the snatch, the swing, and the jerk and got really good at them. Then, I started training clients..”  

Nowadays, Leija is the resident kettlebell. guru at Onnit. He still implements the barbell and dumbbell training he picked up as a teenager from Arnold Schwarzenegger’s Encyclopedia of Bodybuilding, but his routines don’t require as much heavy lifting. now—for good reason.   

“I started having a lot of joint pain, and my back and shoulders were hurting a lot” Leija explains. “I wasn’t paying attention to my mobility or durability I was just kind of going hard and heavy all of the time. I use kettlebell movements to maintain my level of strength without putting my body under a lot of stress..”

You cannot (and should not) build up to a heavy one-rep max using kettlebells, Leija says, but he likes them for two major reasons: First, you can train hard with them and still tax your muscles using submaximal weight. Because the load is on the lighter side, you’re less likely to hurt yourself. Also, they’re more versatile than a barbell. 

Most compound movements. like deadlifts. are pretty one-dimensional as far as movement is concerned. You lift the weight up and down. Leija likes to spice up kettlebell exercises by adding movement to them, such as a twist at the top of a press or a lunge after a clean. This, he says, is a more athletic way to train and prepares your body for the type of movement you experience in real life—such as swinging a golf club or tossing your kid (safely) in the air. 

To add kettlebells to your program, Leija recommends performing them either with light weight., as a warmup, or after your main compound movements as accessory work. If you’re tight on time, you can also string a few kettlebell moves together to form a sequence or, as Leija calls it, a flow, for a complete training session. 

Start by mastering the five moves below, all demonstrated by Leija, and then work on the flows he also provides. 


“This move really lights up my lats and upper back,” Leija says. “And if I’m doing deadliftsor a lot of pulling, it helps me to reinforce a strong hinge position with that side-to-side shifting so I’m more familiar with position changes.”

How to do it:

  • Start with feet shoulder-width apart and a kettlebell next to the inside of one of your feet.
  • Hinge at your hips, keeping your back neutral, to bend over and grab the kettlebell with one hand. Row the bell up until your elbow passes you torso and then let it go.
  • Quickly grab the kettlebell with your other hand and let the bell float back towards the floor before rowing it back up.
  • Keep repeating this back and forth without letting your torso twist to one side. 

Pro tip: “Suck in your pelvis as far back as you can, you should feel your hamstrings light up,” Leija says. “Don’t flex or round your spine. Make sure that everything is engaged.”


“Even if I’m focusing on my chest and shoulders, I like to hit the legs a little bit just because they’re our foundation,” Leija says. “This is one of my favorite moves to do before floor presses or bench presses, as I’m engaging the legs and glutes and keeping my abs tight.”

How to do it:

  • Get into a bridge position with your heels and upper back planted on the ground and your hips high up in the air.
  • Hold a kettlebell by the base with both hands, and then press it directly over your chest. 

Pro tip: “Tuck your heels in close to your butt, and instead of thinking about sticking your hips up as high as you can, think about driving your knees forward and extending the hips,” Leija explains.”


“This move works your core through anti-rotation [the action of preventing your body from rotating], as you’re fighting not to twist away from the elevated hand,” Leija says. “It also helps me better protract [extend] my shoulder and strengthen that range of motion.” 

How to do it:

  • Get into a standard pushup position with one of your hands on the base of a kettlebell turned onto its side.
  • From there, Lower yourself down until your chest is about an inch from the floor.
  • Drive back up and raise your non-elevated hand up past your torso. 

Pro tip: “Make you go slow and controlled with every rep,” Leija explains. “This isn’t a dynamic exercise. You really want to strengthen the entire range of motion, retracting and protracting your shoulder blades with control.”