Isometrics for hypertrophy aka "It'll never work..."
​
One of the knocks against iso have to do with it supposedly not being effective for gaining lean mass.
Some quick guidelines for isometric hypertrophy work *as I understand it*. The usual disclaimers re other valid approaches with which I am personally not acquainted - this is for overcoming iso as I use it. Included is a bunch of speculation for 'why' I make these recommendations.
I'll also add to the confusion by coming up with my own terms for isometric contractions different from "overcoming/yielding, Push (PIMA)/Holding (HIMA), and any other definitions currently in use.
I have come to think in terms of 'Assertive' and 'Resistive' based on intent. 'Assertive' is an active increasing effort toward higher force. 'Resistive' is a holding effort attempt to maintain a current force level.
Very important to breathe - use a standard exercise breathing pattern of exert hard on exhale, relax on inhale. When gunning for hypertrophy you want to relax the working muscles as completely and rapidly as possible between reps unless you are using static hold across multiple breaths.
Basic static holds can trigger some initial hypertrophy but become less effective over time. A big part of this is twofold:
-a basic static hold is not very energetic. Non contractile elements like titin will kick in, taking some of the tension.
-metabolite turnover in the muscle is reduced, lowering the volume on metabolic downstream signalling that is inseparable from tension when using traditional lifting. Additionally isometrics are most energetic at the initial assertive effort.
These can be countered by:
-during a static hold, rededicate every exhale with more effort. If you use a crane scale you'll notice that your force output goes up on exhale and down on inhale. With a tremendous effort, you can maintain tension on inhale, but only for a couple of breaths. If you allow slackening on inhale, you'll find your ability to hit high % force on repeated exhales is more enduring than you might think, 8-10 breaths.
-use of multiple repeated efforts of several seconds per, using a somewhat casual ramp up. An assertive effort with relax between to allow metabolite and blood turnover in the muscle. For hypertrophy, these should still be held for three or four seconds per. In use these "feel" very much like traditional lifting reps.
-intent to fire explosively into the hold and then maintain that force for three to four seconds, no slackening after the initial effort. Two parts - explode and hold. The hold after the initial 'Assertive' pop, becomes a 'Resistive' effort - you are fighting the stretch of non contractile elements trying to return to their resting lengths.
Using a scale to benchmark these, I found that the explosive efforts generated between 10 and 20% more force than a slow ramp up. I expected this, after observing how much my plywood deck deflected on the ends when using these compared to a slower start. What I didn't expect was that I could maintain a higher level of force (it wasn't just a spike) than I could even reach using a slower start over several exhales. Difficult to explain this in any light other than resisted eccentric(ish) contraction.
In use, I structure every set in two parts - initial static effort or initial string of explosive efforts, followed by pulse efforts. These are typically 10 breaths of each. On squat and deadlift I often cannot hit 10 pulse reps on my last set.
Alternatively a high effort rapid limb movement interval can be used in place of the pulse efforts, as the second half of the set. Jump rope, sprint in place, sprint bike etc. This provides the metabolite turnover and downstream signalling boost to accompany the tension component. An added bonus made possible by the reduced metabolic load from isometrics - when combined with intervals it improves cardio markers of resting heart rate and resting blood pressure.
Overall set volume is going to be similar to traditional, with the rep count (determined by breaths) a good bit higher than typical. I use two sets when combining it with intervals, three sets when combining it with pulse reps.
Me at start of Isometric training 5 years ago age 54:
https://imgur.com/a/ovcEt08#TrJvIqc
Me currently, a few weeks from 59, a huge thank you to everyone who told me it'll never work: