Eva Lopez Protocol

reboot wrote: Ok, I don't necessarily have an issue with that, but I assume the maximal isometric tetanic force does decrease over time w/o resting. So with intermittent stimulation, it's likely the average force output is higher than a continuous stimulation (i.e. the muscle will be doing more "work" externally),

Actually, that was the thing: the intermittent/short duration protocols show greater fatigue, a la the isotonic protocols, and therefore the force production is lower. More work = more energy = more fatigue.

reboot wrote:that's not to say rapid repeated cycles of tensioning/relaxing the muscles may be more fatiguing somehow. Although I doubt that's applicable to climbing (maybe besides the Elvis leg syndrome?)

I think it could be very applicable in the form of understanding how to train with regard to fatigue development since this directly affects muscle recruitment. It's also involved in anaerobic threshold.

slim wrote:i thought reboot's question about 30 seconds straight versus 5 on 5 off X 6 was a pretty good question. it doesn't seem possible that you could do this with the same loads(?).

You can do it with the same loads as long as you create a load which can be performed for the long duration/continuous contraction protocol and use that.

slim wrote:does this mimic voluntary exertion pretty well, in terms of the levels of recruitment, failure, etc? when i think of electrical stimulation i guess i think of flipping the switch, the muscles lock down indefinitely until you turn the switch off.

E-stim is not on/off. There is a switch(es), yes (lol), but the voltage is completely adjustable to vary the muscle's response - which depends on the muscle being stimulated, the physiological state of the muscle at that point in time, the person, etc.

As for whether it mimics voluntary exertion, well, I would hazard a guess that creating maximal tetanic activity in a muscle is (mostly) the same regardless of whether it's electrically induced from an outside force or electrically induced from the brain/motor axon (although voluntary exertions would still probably exhibit more fluctuations). However, the only research I have personally done in fatigue is with EMG-force calibration curves which involve EMG recording of voluntary isometric exertion using various load scenarios (and without measuring blood metabolites), so this is kinda outside the scope of my knowledge.

i guess i am still confused by this, you can obviously use a load that can be used for both cases (this load would be pretty low for the 5 on 5 off compared to what you would use if you were doing this exercise at your limit). however, this doesn't really seem like it would produce results that are really of interest(?).

i would think that you would want to use whatever load is at your limit for the 30 second rep, and compare the muscle responses to whatever load is at your limit for the 5 on 5 off.

so, boiling it all down - it sounds like with the same load, more fatigue is caused by the 5 on 5 off than with 30 seconds on? this doesn't seem to make sense(?).

slim wrote:i would think that you would want to use whatever load is at your limit for the 30 second rep, and compare the muscle responses to whatever load is at your limit for the 5 on 5 off.

You could be right, and maybe this is exactly what they were doing with the e-stim-induced maximal isometric contraction. Doing the same thing with outside loads and voluntary exertion would be far more finicky to dial in for each "set" as fatigue occurs (in a research study, that is). The reason I was thinking one would use a single load for both protocols is to control that variable. But I don't know too much about this type of research so I am not sure what is considered good methodology.

slim wrote:so, boiling it all down - it sounds like with the same load, more fatigue is caused by the 5 on 5 off than with 30 seconds on? this doesn't seem to make sense(?).

Again, most studies do not use an external load except when testing isotonically. It seems they measure force output via the muscle reaching tetanus and then sustaining it for the pre-determined time period. They induce the tetanus using an external e-stim source since I would imagine the participant cannot manipulate the response like they could with a voluntary effort.

Also, I don't believe a purely maximal isometric effort is required to see these patterns. You can reach tetanus in submaximal conditions and fatigue will still occur over time. You don't need ridiculous amounts of fatigue, you just need to see comparative patterns and outcomes.