Strength = Power Part 2: Train your Superpowers!

Welcome back to part two of our Coach’s Corner discussion on the exciting skill of wielding great strength at high speed; also known as power – the super hero edition! In our previous newsletter we addressed the importance of maintaining some degree of explosive athleticism as we age. A recent study on the subject was even able to conclude that the bare minimum power output for us to keep living independently is likely about 23.7 watts per kilogram of bodyweight. This represents the brawn required to simply get up out of a chair, move around and get back down again in a safe and reasonably efficient manner. If you’d like to catch up on all the details of that earlier newsletter, you can find it here:

Now, having established the obvious importance of maintaining our strength and the ability to use it explosively, let’s take a deeper dive into some of the methods for training this skill more safely and effectively. As Peter Parker’s adventures have taught us, “with great power comes great responsibility," after all!.

Speaking of Spider-Man, there are few heroes form our modern comic mythology who are depicted in as thrilling and athletic a style as he is. As such, he’s always been one of my favorites. From the character’s inception, he has been drawn in some of Marvel’s most dynamic and explosive frames of all time. Often leaping effortlessly to impossible heights only to land adroitly, posed in a perfect deep squat, or fearlessly swinging like a gymnast from the flagpoles and traffic lights above Manhattan – this is a character who expresses the thrill of possessing explosive strength!


How then can we, without the benefits of a radioactive spider bite, get a taste of this ebullience? Virtual reality? Springy footwear? Not necessary or even all that practical! Clever coaching and programming is all that we need to tap into our inner power. Enter the concept of “Tri-Phasic” training, a fascinating paradigm coined by Calvin Dietz at the University of Minnesota, but based on some age-old movement principles used by everyone from the warriors of ancient Greece to the yogis of India.

The crux of this training methodology is that if we study any dynamic human movement, an obvious recurring pattern is revealed as to how the body is able to generate force. Whether it’s a squat, hinge, push or pull, the body will perform some aspect of an eccentric, isometric, and then concentric movement. These phases could also be described as a loading phase (eccentric), a firing phase (concentric), and the moment of high tension that exists between those two (isometric). These are the three phases referenced in the name “Tri-Phasic” training.

Unfortunately, many of today's popular fitness methods only emphasize the concentric action when it comes to producing power. Although the concentric phase is the “sexier” part of the movement (locking out the squat gets big cheers, while going down into the hole does not), disproportionate emphasis on this phase in training results in less powerful, “half cocked” movements. This is why there are requirements to squat below parallel or pause in the bottom of a bench press in the sport of powerlifting; it represents a greater feat of strength mastery to control all three phases of the lift, not just the last part of it. In order to reach our true power potential, we must train eccentric and isometric aspects of dynamic human movements with as much zeal as the concentric ones. This is like our very own dose of gamma radiation to produce super powers like those possessed by Spider-Man or The Incredible Hulk! Sounds exciting, but what exactly does it look like? Here’s a little more detail on each phase and how we might train it:

An eccentric action can be described in kinesiological terms as a movement causing the proximal and distal muscle attachment points to move away from each other. In more plain language, this usually refers to a muscle lengthening or yielding phase while under load. Since every single dynamic movement begins with an eccentric phase, it is such an obvious training target that it often gets overlooked; hidden in plain sight. But if you want to jump, for example, you have to dip at the hips and knees first, otherwise it’s not much of a jump. Teaching athletes to expel energy is important, of course, but learning the skill of absorbing it is perhaps even more so.

As it turns out, our muscles can actually generate more force under eccentric conditions than the other two phases of a lift. Growing research in the field of injury rehabilitation is putting more and more emphasis on eccentric training because it makes our explosive movements safer to perform and helps to reestablish proper joint functionality. An effective method to train the skill of loading up or absorbing more potential energy, is to use slow movements (5-8 seconds) through the eccentric phase of a lift with loads between 55-85% of a maximal effort. The availability of competent spotting and assistance, especially with loads above 80%, is a must for this type of work! Even though the eccentric part of the lift is performed slowly in this case, it’s still a good idea to try to accelerate the load on the concentric. Remember that we are trying to teach ourselves to be more powerful overall, so signaling the central nervous system to change over from the eccentric to the concentric with as much alacrity as possible will make us faster at moving the load, hence explosiveness!


Isometric action occurs when the distance between the proximal and distal muscle attachments remains the same. You might think of this as a moment frozen in time, not going up or going down but stuck somewhere in between. The key with training the isometric phase of a movement is to emphasize taking all the potential energy created by an eccentric movement and diverting it maximally into the concentric, without any leakage. A harder stop at the end of a muscle lengthening phase will produce greater force recoil and make the shortening phase more explosive. To work on the skill of harnessing potential force and turning it around to produce force (without losing any along the way), a pause is used at the end of an eccentric movement and held for several seconds before accelerating into the concentric. While frozen in this moment of high excitation, it’s important that an athlete practices creating even more tension by squeezing the muscles involved as tightly as possible. For more advanced practitioners, speeding through the eccentric phase and stopping at the isometric point as suddenly as possible will produce even better results; “you want to hit the ground like a brick!”

A concentric action takes place when the proximal and distal muscle attachment points move toward each other. This is the jumpy part of a jump and the punchy part of a punch. In this phase of movement, all the energy that an athlete has worked so hard to create in the other phases finally gets released. Training this phase seems simple; move fast! The real magic occurs when we train this phase with great respect for the other two. The focus is on reproducing the flawless movement of the slow eccentric in reverse and bouncing off the hard stop of the isometric. If we can create seamless synchronization, high speed, uninhibited, coordination of inter-muscle contraction, then we’ll be frighteningly powerful. Just like our favorite comic book heroes.

Hopefully this brief overview of training the three phases of a dynamic movement can offer some insight as to how we might improve our power potential. Taking on the responsibility of mastering these aspects of explosive energy production will not only make us more powerful athletes, but will keep our joints safer and maintain our freedom of movement for many years to come.

Cheers! Caleb

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