Nov 28, 2018
ROM Challenge
Tim DiFrancesco

I’ve recently had a number of folks ask about what the “kBox thing” is that I keep showing in my videos. Like in this video.

I figured that if that many people were wondering about it, I may as well shed some light on it. The kBox4 by Exxentric is one of those tools in my training toolbox that I often wonder how I would do without now that I’ve experienced its value.

I always approach writing a training program with the same primary agenda: How can I help this person be more durable to do what they love to do. Don’t get me wrong, there is no magic bullet to athletic durability and you will always have to put the work in and spend the time under tension to get the results, but the key is applying the right training modes, methods, and modalities. I have a very short list of training equipment that I consider a lock for promoting physical durability and the kBox4 is right up there.

The differentiating feature of the kBox4 and the flywheel training that it allows for is that it offers isoinertial resistance. Let’s take that fancy word and simplify: Imagine you were lifting weights on a cable that acted like a yoyo and as you pull it up it generates force that’s going to pull you back down. This is clutch because in traditional weight lifting or cable machine work the resistance levels vary depending on your joint angle and position. During use with the kBox4 and the flywheel technology, you get constant resistance at all ranges of motion throughout the entire repetition. You’re getting more challenge on your muscles during more range of motion.

On top of that, the harder you pull on the flywheel, the more energy it stores up and the harder it pulls back on you. This means that the eccentric loading is significant during use of the kBox4. You have to work hard to slow this thing down, and that makes the exercise special. Your ability to slow yourself down or decelerate during physical activity and sport is one of the keys to both performance and durability. Eccentric loading or the lowering phase of resistance training is one of the most valuable currencies in the search for structural durability for sport. I’ve found that the kBox is a jackpot for eccentric loading.

Now that we’ve cleared up what’s going on with the kBox4, let’s look at a few of my favorite exercises with it:

1. kBox4 Split Squat: This exercise challenges your patellar tendon as well as surrounding quadriceps and gluteal muscles of the hip. It promotes knee health, lower body strength, control with deceleration and even core stability. Click here to see a video of it.

2. kBox4 Kickstand RDL: This exercise challenges your posterior chain and in particular your hamstrings. Eccentric loading of the hamstrings is one of the best ways to prevent hamstring injury. Click here for a video.

3. kBox4 Split Stance 1-Arm Row: This exercise challenges your core and upper back muscles. It’s a great way to build upper back and postural endurance while building better core control to help prevent low back discomfort. Here is a video.

4. kBox4 Step-Up: This exercise works your patellar tendon, the surrounding quadriceps, and gluteal muscles of the hip. Like the kBox split squat, it also promotes knee health, lower body strength, control with deceleration, and core stability. The video is here.

5. kBox4 Lateral RDL: This exercise is a hybrid between the traditional lateral squat and a sumo RDL. It’s a big hit in my book because it targets hamstrings, groin/adductors, and the low back. It’s a great one for reinforcing durability in those commonly aggravated areas of the groin, hamstrings and low back. Click here to see it in action.

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Tim DiFrancesco, PT, DPT, ATC, CSCS, spent six seasons as the Head Strength & Conditioning Coach of the Los Angeles Lakers and is the founder of TD Athletes Edge. He is nationally renowned for his evidence-based and scientific approach to fitness, training, nutrition, and recovery for athletes and fitness enthusiasts.


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