JONGSON PARK

Part 3: So much power comes from tendons.

Tendons have the tensile strength ranging from 50 to 150 MPa, bones by comparison have a tensile strength of 150MPa¹. The achilles tendon can bear load stress of 8 times the body weight while running².

Functionally, the tendons must be pliable and elastic to elongate and let the joints move without restriction. But they must also be able to lock in rigidity at the joints when the body is delivering force into the ground. That is, for example, while sprinting the tendons and joints must be rigid in lock stiffness, absorbing and returning the kinetic energy that is being produced from the momentum of the body and the muscles creating the movement. While running the tendons are able to return 40% of the energy from the body, into the ground and back into the body³.

This varies depending on your running style. With the “eyeball test” we can visually see someone that is able to run with elasticity in their tendons, they look like they’re bouncing off the ground, as if they’re running on a trampoline. While another running style, looks like their legs are pumping, driving like pistons into the ground, they look like they’re running with all their “big” muscles to sprint – quads, hamstring, glutes, etc. The second method not requiring as fast and elastic tendons as the first.

How fast and elastic a tendon is depends on the tendon’s pliability, that is the ability for how quickly the tendon can go from released state to flexed stiffened state. In this capacity not all tendons are trained equally. Visualize the pliability action of a tendon on a bell curve with the peak of the curve being ground contact. Jogging, let’s say, is a wide bell curve and sprinting requires a narrow bell curve. The tendon’s reflexivity in jogging doesn’t require a narrow bell curve, because the ground contact is longer than sprinting and the leg has more time to stiffen and release as it cycles around. While sprinting require a narrow bell curve because the ground contact is so concentrated in a smaller fractional time and must go into flex and get back into the leg cycle almost instantly as it springs up from the ground.

Take another example of the importance of the tendon’s pliability, the ability to decelerate to a stop quickly depends on how fast and strong the tendons can hold that joint position, injuries will occur if the tendon is too weak and involuntarily gives way. Just because you can squat a heavy load doesn’t necessarily translate to being able to stop on a “dime” when sprinting at your max speed.

The pliability of the tendon is dependent on its length, strength and mobility. But also muscle control mechanics – the ability to completely control the release and contraction from the central nervous system. That is why the pliability requirement of jogging is not crossover compatible to what the equivalency would be as a sprinter. The length and mobility requirement is different, a jogger’s legs are cycling in a mid-range motion, and even short-range, never pushing toward the end-range positions. The strength component is different, the speed in jogging does not reach the force and velocity of sprinting, which produces greater loads. And the muscle control mechanics are different, jogging is training the tendons to reflex in the wider bell curve, going from wide to narrow bell curve reflex requires re-trained neural pathways, new muscle control abilities, and increased strength and length requirements.

References
¹ https://link.springer.com/chapter/10.1007%2F978-1-4757-2968-9_8
² https://en.wikipedia.org/wiki/Achilles_tendon
³ https://www.ncbi.nlm.nih.gov/books/NBK513237/

Part 2: How to strengthen & lengthen your tendons.

The tendons will only get as strong as needed by the muscles. i.e. the tendon’s standard of total force of the muscle’s total output. With regular workouts the tendons will only work as hard as the force put out by the muscles. Hence tendons will not maximize the tendon’s total potential strength.

Typical squats, curls and pushups never really go into deep range of the motion. For example, in a squat the person might stop parallel to the ground or just below but usually not all the way to the ground. Repeated mid-range squats will shorten the tendons in the knees, hip and ankle joints. Strengthening them in those positions but not strengthening them in the end-range positions, full flexion and even full extension.

My current tendon strengthening program for legs, hip, knee, ankle and feet. I do the following sections in sequential days.

Relaxed Deep End Range Positions

Maximum and increasing end range positions in a squatted position. No concentric work yet. Just sitting in a full squatted position to the ground and being able to fully bend the hips, knees and ankles. Remember no concentric work, no reps yet. Just sit in this position for at least a minute.

• The progression is going from body weight where your tendons might tighten up in the deep flex trying to protect itself because the tendons are so short.
• To being able to sit in that position with your knees, hips and ankles able to release and go deeper into that position, the tendons are lengthening.
• Now start adding weights to hold in that position, remember still not doing any concentric work it’s letting the weight push you down deeper into those end range positions. This is lengthening your tendons even more, time under tension, weights while your tendons are lengthening, which equals strengthening.

As an experiment try this in a push-up position. Relax into a deep push-up position, getting a nice lengthening in the deep shoulder tendons. After about 45 seconds to a minute hold, ease out of this position, don’t push-up, just relax out of it. Now do some regular pushups, the pushups will feel very easy, the shoulders will not tire first as they usually do in a pushup.

Bodyweight Pumps

Using the squat as an example. First, explaining the “pump”. Short range motion of about 15-25 degrees, rhythmic up and down (concentric/eccentric) action of the joint position. i.e. short range up and down motion in a mid-range squat position. So not going all the way down or all the way up.

Doing about 15-20 of these, not past discomfort. The short range pump helps focus the action to come from the tendons and not the main muscles, quads etc. The tendons in the knees should start to feel hot.

Now do this pump in the three positions of the squat position. i.e. mid-range, top-range, bottom-range. So that you are pumping the full range of the squat in all the different positions but separately.

Resistance Bands

For the third day of training I use resistance bands to start introducing some more resistance into the movement. Continuing on using the squat as the example, I’ll use a resistance band in the full squat exercise. It is important to keep getting into the full end range motion. Not quite the level proper eccentric training but focusing on slow eccentric movements would be good here.

Free Weights

The next day, I’ll use free weights in the exercise. Enough weight, where it starts to get challenging at 80% of max repetitions. I don’t go to full max reps or failure. I’m leaving enough in the tank to recover for the next day to repeat the cycle over again. Again it’s important to do the full end range motion.

I repeat these four sequences on a daily basis

• Day 1 – Deep end range – isometrics
• Day 2 – Bodyweight pumps
• Day 3 – Resistance bands – eccentrics
• Day 4- Free weights – concentrics

Plyometrics

I do a light, medium or intense plyometrics everyday. Ultimately my goal is to be able to move freely and uninhibited like a child’s joint and limber movements. And also get my tendons and joint healthy and strong to be able to perform powerful, explosive athletic actions. With pliability and rigidity – pliable to move the joint in its full range with the tensile strength to absorb and recoil the force created in the body into the ground, locking the rigidity in the joints. For example, the ankle joint must remain rigid at the point of contact in the ground when running so that there is no energy leakage in ground force production, and the energy can be sent into the ground and returned back into the body to propel it forward.

On a side note, I would like to introduce or figure out a way to do an eccentric overload program. Hopefully that will be in a later post if I figure it out.

The importance of joint and tendon health, maintenance and strengthening.

Tendon health is an overlooked and under-focused health development for everyday strength maintenance and movement longevity. The focus is usually on gaining muscle mass and targeting the bigger muscle groups.

Targeting joint and tendon health should be a focus for the complex functionality of biomechanics. One of my hypothesis is that in the long run tendon strengthening will also, actually unlock and delimit muscle growth potential.

Tendons have the capacity to be many times more stronger than muscle. Tendons are not usually targeted because it is assumed or taken for granted that tendons will just strengthen while working out and strengthening muscles. Tendon strength is crucially more important in athletic movement and sports than in just gym work and weight lifting, and the plyometric movements in a sports activity usually help strengthen tendons but a strength-only focus may not incorporated plyometrics into their routine.

The human body is a very smart system. The biomechanics of a running leg is a very complex function. The hip, knee, ankle and feet joints must work together to move properly and efficiently. But the nervous system will also limit the body from “over-clocking” the leg if there are any weak points in the system. The leg is creating a tremendous amount of ground force when running, theoretically it could run harder than the system is able to handle, i.e. the legs run so hard it breaks the ankle. So the nervous system will restrict the leg muscle’s total output and power, if the ankle or knee joints are weak, so it doesn’t cause injury or pain. Also for example, the body will not allow the bicep to output more force than what the elbow or wrist joint can hold together. The weakest points in a movement is usually in the joints.

Building more overall strength in the tendons, the ability to lock the joint in place, producing a rigid and immovable joint while producing force into the ground, preventing energy leakage, will unlock the muscles potentiation, allowing it to engage, fire and activate, recruiting more muscle in the action. Requiring more muscle for the action to produce more explosive power, hence stimulating hypertrophy.

Why strengthening tendons is not usually a high priority. As stated before it’s usually assumed tendons will strengthen as muscles strengthen and tendon pliability isn’t usually a focus outside the need of explosive athleticism in sports. But other reasons are, strengthening tendons is not glamorous. Tendons are “under the hood” strength, it doesn’t build the vanity and aesthetic muscles. But also the objectives, measurable and philosophies aren’t standardized, as in there isn’t a quantifiable approach to how and what is strengthening tendons. I know if I can bench press more weight, my muscles are getting stronger, but how can I target and specifically measure that my tendons are getting stronger. I also think, people don’t necessarily think it’s possible to target tendons to get stronger. Tendons also take longer to strengthen but will also retain its strength longer than muscles.