Q&A: Bodyweight Training and Intentional Antagonistic Co-Contraction

Question:

I am using Project Kratos at the moment and you advise to squeeze your muscles at the fully contracted position on pulling movements and hold at the bottom position on pushing movements as a way of making the exercise harder. Sometimes when I do a wall squat after about ninety seconds my legs will get a little shaky. At this point I will tense/contract my whole lower body, I can tolerate this for about ten more seconds before failure (or more likely I give up).

Would it be beneficial to fully contract the muscles at the beginning of a static hold, or even during dynamic movements?

Answer:

It is possible to significantly increase the difficulty of both isometric and dynamic bodyweight exercises by intentionally contracting the antagonists – the muscles that oppose the actions of the target muscles or agonists – but you should build up gradually rather than contract as hard as you can right from the start. If you allow the target muscles to fatigue somewhat first you won’t have to contract the antagonists as hard and I have found it easier to control and sustain the antagonistic co-contraction this way.

For example, when performing a wall squat or squat hold you should do so normally for about the first thirty seconds, then gradually start to contract your hamstrings and quadriceps harder, taking around five to ten seconds to slowly build up to a maximum effort.

When performing dynamic exercises intentional antagonistic co-contraction (IAC) should be started after the second or third repetition, with the build up occurring during a hold at the start point on pushing movements and the end point or “fully contracted” position on pulling movements. For example, when performing push ups when you return to the start point after the third rep, hold yourself there motionless while starting to contract your biceps and back against your chest shoulders and triceps,  taking around five to ten seconds to slowly build up to a maximum effort, then slowly begin the next repetition while continuing to contract as hard as you can.

It helps to practice this while standing, pushing your arms forward and pulling them back working the chest, back, shoulder, and arm muscles against each other. Pay close attention to your breathing, as people have a strong tendency to hold their breath while doing this. There have been many exercise programs based on IAC alone (notable examples include Charles Atlas’ “Dynamic Tension” and Harry Wong’s “Dynamic Strength”) but, since you may not be able to fully activate antagonistic muscle pairs simultaneously, additional external resistance may be necessary for maximum effectiveness.

This is something I experimented with earlier during Project: Kratos and considered including in the book but found it difficult to teach and impossible to quantify (without equipment). While it appears that IAC can make bodyweight exercises intense enough for even the strongest  trainees (assuming relatively balanced strength between antagonistic muscle groups), it takes a lot of practice to do it well.