Isometric vs Isotonic

Would like to know everyone’s opinion on the subject. ^^^

There are a lot of really knowledgeable people here and it has been great learning from all of you.

Discuss please.

When you say isotonic, do you mean true isotonic with specialized equipment such that the force is the same throughout the entire range of motion? Or are you referring to the more applicable exercises we all do, such as a barbell curl where the load is the same throughout the movement but the tension is not (ie, if the bar has 100 pounds, when you are at a sticking point and it is barely going up you are applying approximately 100 pounds of tension but when it is moving up more quickly you are applying more than 100 pounds)? The other consideration besides bar speed is the strength curve; for the barbell curl at the very beginning you are moving the bar more horizontall than vertically (ie, not against gravity) but then when your arms are ~90 degrees you are moving the bar almost completely vertically so the actual weight you are moving against gravity is considerably higher. In a curl machine this is not the case as the weight you are moving is the same throughout the movement.


Also, are you curious with respect to hypertrophy, strength, or some other variable?

[QUOTE=Heisman2;1617637511]When you say isotonic, do you mean true isotonic with specialized equipment such that the force is the same throughout the entire range of motion? Or are you referring to the more applicable exercises we all do, such as a barbell curl where the load is the same throughout the movement but the tension is not (ie, if the bar has 100 pounds, when you are at a sticking point and it is barely going up you are applying approximately 100 pounds of tension but when it is moving up more quickly you are applying more than 100 pounds)? The other consideration besides bar speed is the strength curve; for the barbell curl at the very beginning you are moving the bar more horizontall than vertically (ie, not against gravity) but then when your arms are ~90 degrees you are moving the bar almost completely vertically so the actual weight you are moving against gravity is considerably higher. In a curl machine this is not the case as the weight you are moving is the same throughout the movement.


Also, are you curious with respect to hypertrophy, strength, or some other variable?[/QUOTE]

As I understand it, strength at a particular lift isn’t unmarried from hypertrophy. But some sources that I read when you perform isometric exercises, you only get stronger at that position held.

As another example, a glute bridge/hip thrust could either be held for time or performed for reps. In that case, what would be better?

The general rule of thumb for an isometric is that you get stronger in 15 degrees both ways of the joint angle at the position. To me it is a type of special strength that you probably don't need to train outside of a very advanced powerlifter or oly lifter.
My old gym had the ancient York Isometric rack and I don't know how you would really do things correctly without something like that too.

[QUOTE=BeginnerGainz;1617645361]As I understand it, strength at a particular lift isn’t unmarried from hypertrophy. But some sources that I read when you perform isometric exercises, you only get stronger at that position held.

As another example, a glute bridge/hip thrust could either be held for time or performed for reps. In that case, what would be better?[/QUOTE]

[QUOTE=powerlifterer;1617648191]The general rule of thumb for an isometric is that you get stronger in 15 degrees both ways of the joint angle at the position. To me it is a type of special strength that you probably don't need to train outside of a very advanced powerlifter or oly lifter.
My old gym had the ancient York Isometric rack and I don't know how you would really do things correctly without something like that too.[/QUOTE]

This is how I understand it as well.

Wow that York rack is a relic at this point.

[QUOTE=BeginnerGainz;1617645361]As I understand it, strength at a particular lift isn’t unmarried from hypertrophy. But some sources that I read when you perform isometric exercises, you only get stronger at that position held.

As another example, a glute bridge/hip thrust could either be held for time or performed for reps. In that case, what would be better?[/QUOTE]

With initial strength increases there is a big disconnect from hypertrophy as initial changes are mainly neural or neuromuscular in nature. As one becomes more advanced, there is more correlation. Isometrics do generally lead to the most strength gain at the angle studied and then +/- 15 degrees as powerlifterer mentioned. However, the can be used for hypertrophy as well. See the following few sentences I've included from this review ([url]https://pubmed.ncbi.nlm.nih.gov/30943568/[/url]) (not open-access... my apologies to anyone who thinks it is wrong for me to post these few sentences):

Here IST: isometric strength training, CMJ: counter movement jump, MVC: maximum voluntary contraction. Also, ballistic refers to generating force as quickly as possible.

[quote]It is recommended that IST be performed in concurrent with dynamic strength exercises as performing IST alone might not be beneficial to activities that involve the 3 phases of stretch shortening cycle such as CMJ. In addition, the effects of IST alone on strength trained athletes have not been well studied. When the objective of training is to in-crease muscle hypertrophy, IST should be performed at 70–75 % of MVC with sustained contraction of 3–30 s per repetition, and a total sustained contraction duration of > 80–150 s per session for > 36 sessions, while adopting a joint position that induces long muscle length. If the objective is to increase maximum strength, IST should be performed at 80–100 % MVC with a with sustained contraction of 1–5 s, and a total contraction time of 30–90 s per session, while adopting multiple joint angles or specifically targeted joint angle. It is also recommended that IST to be performed in a ballistic manner so as to maximise the improvement of RFD[/quote]

[QUOTE=powerlifterer;1617648191]The general rule of thumb for an isometric is that you get stronger in 15 degrees both ways of the joint angle at the position. To me it is a type of special strength that you probably don't need to train outside of a very advanced powerlifter or oly lifter.
My old gym had the ancient York Isometric rack and I don't know how you would really do things correctly without something like that too.[/QUOTE]

I agree it is not needed but it can be a good tool for additional work on sticking points. You could do isometrics in a regular power rack by setting safeties just above the sticking point and pressing the bar up into them (bench press), squatting the bar up into them (squats), or pulling the bar up into them (deadlifts).