Does aerobic endurance increase structural strength?

[REG]

Hello. I have diligently read all of Tom Kurz's column articles and according to Tom Kurz, in article column 24, he says that "Endurance training, that is, doing many repetitions per set against low resistance, increases structural strength of slow-twitch muscle fibers (Gleim and McHugh 1997). Such training also increases the structural strength of the connective tissue within the muscle, probably through the anabolic action of hormones that are delivered to the muscle with the increased blood flow (Tipton et al. 1975). The connective tissue damage is considered another one of the causes of delayed-onset muscle soreness (McArdle, Katch, and Katch 1996)." So my question is wouldn't doing any form of aerobic endurance training also increase the structural strength of both the slow-twitch muscle fibers and the connective tissue within the muscle, since aerobic endurance training consists of doing thousands of repetitions utilizing all your type 1 muscle fibers throughout your entire body? I would very much appreciate it if anyone could answer this question.

[REG]

Hello? Is there is anyone out there who could help me with this question please?

[dragon]

I'm certainly no expert on this subject but i'll explain it how i see it....

The high rep/low resistance exercises Kurz recommends in his material are to /strengthen/condition/prepare the connective tissues for isometric stretches(or any other activity that would stress the connective tissues).The exercises are to be performed with a full ROM with a complete stop at the biginning and end of each rep...

This would include deep lunges,side lunges,full squats,etc.

If you perform a traditional aerobic exercise such as running,skipping,etc, you aren't moving through a full ROM,and there are no full stops at the beginning/end of each rep to put the connective tissues under stress.

Depending on your fitness level,a strength endurance exercise could become aerobic.....But i wouldn't consider an aerobic exercise to be strength endurance.

Dragon.

[REG]

Ohh okay, well I kinda get it. Though I am still somewhat confused, because Mr. Kurz said that during running you should be moving through a full ROM. Also, why exactly are the exercises to be performed with a full ROM with a complete stop at the beginning and end of each rep?

[dragon]

There is a difference between performing a full ROM for a given exercise and a full ROM for a given joint-For example,you may be able to perform a full front split,but you certainly couldnt move your legs that far apart whilst running.So you perform the full ROM that each particular exercise allows.

The exercises need to be performed at a full ROM to strengthen the connective tissues-As Mr.Kurz explains in his book,it makes no sense using a thigh adductor machine at the gym that only allows you to extend to 120 degrees if you need to strengthen the connective tissues to perform at 180 degrees( or words to that effect).

A full stop at the beginning and end is applied in my opinion to:-

1)Stop momentum.An exercise becomes easier if it starts to become ballistic.You see this in gyms with people swinging barbells during bicep curls or bouncing the bar off their chest during bench press.These individuals would be either doing far less reps or with far less weight if they did the exercise strictly.

2)The pause in the bottom(deep position) will again lead to a greater degree of conditioning.This is a lead up to being able to hold a stretched position in isometrics.

Practical experience is always better than theory though.If you have any doubts,give both methods a try-Perform half squats at a relatively high speed with a constant rhythm..........Then perform full squats with a pause at the bottom.I'll say you'd be able to perform less reps and be more sore the day after the second method.

Dragon.

[REG]

Oh I see. So, would you say that the exercises need to be performed at a full ROM to strengthen the connective tissues, are used to balance or even out the strength of the joints and connective tissues of a given muscle group? Also, how long are the full stops at the beginning and end of each rep supposed to be?

[dragon]

Strengthening your connective tissues does just that-Strengthens the tissue at the insertion point...I think it would be impossible to truly "balance" the strength of the muscle and the insertion point strength ratio....For example,doing push ups with your arms wide apart will always be harder than conventional push ups.

The full stops don't have to be held for any length of time.It's just a "stop" to ensure the exercise isn't ballistic and you're relying on your own muscular strength as opposed to using momentum.

Dragon.

[REG]

So the full stops at the beginning and end of each rep are held for about a split second and are done to make sure that you utilize good form and control during weightlifting movements?

What do you mean by saying "..at the insertion point?"

In addition, in referring back to what you said earlier,

There is a difference between performing a full ROM for a given exercise and a full ROM for a given joint-For example,you may be able to perform a full front split,but you certainly couldnt move your legs that far apart whilst running.So you perform the full ROM that each particular exercise allows.

I was thinking that since that is true, then why does Kurz say that in order to improve or maintain good flexibility in your legs while training to improve or maintain good aerobic endurance, that you need to do running and never use the bicycle, because the bicycle can't have your legs go through the full ROM like running can?

[dragon]

Yes,that is what the full stops are for..

The insertion point is the connective tissue-Where it connects(or inserts)...This is the "weak link" in a muscle and needs to be strengthened in order to be able to perform/handle workloads in extreme ROM.

The reason why running is recommended over cycling is because sitting on a seat pedalling can actually reduce flexibility as it will tighten the hip flexors.Most people have tight hip flexors naturally due to the average daily lifestyle-Sitting in a classroom,sitting in an office,sitting in a car,sitting watching TV,etc.....There aren't many reasons for a person to extend the thigh behind them whilst keeping their trunk upright(and therefore stretching the hip flexors).

Running puts the joint through a better ROM.

Dragon.

[REG]

I see, so the insertion points are the connective tissues all around the given muscle group and joints? Right?

So then when you are running, even though you said before:

...you may be able to perform a full front split,but you certainly couldnt move your legs that far apart whilst running...

, do still need to extend the rear leg pointed backward nearly horizontal while keeping your trunk upright as if doing half of the front split?

[dragon]

The insertion points/connective tissue are where the muscle connects.For example,with the bicep,the connective tissue would be the front of the shoulder and the inside elbow.....To put plainly,either end of the muscle.

I think you are over analyzing your workouts far too much.Whilst it is important to understand what you are doing and why,trying to make the changes you describe(in regards to running) could lead to injury.Make each movement in whatever you do as natural as possible.When running,just run....This will be your natural full ROM.

Dragon.

[REG]

Sorry, I do have a tendency to overanalyze things. It is actually true according to much scientific research and discussion on running that trying to make changes in your running form can lead to injuries. However, according to the Fall 2007 newsletter, Kurz seems to urge a certain correct running technique saying "Running is the most commonly used form of movement for developing general aerobic endurance. It is a simple, natural movement, yet people can do it wrong. Here is a description of the correct running technique:....." All of this confuses me.

Regarding running and flexibility, you're saying that even if I jog at a slow pace and/or with short strides, I should still be able attain or maintain enough flexibility in the hip flexors for the full front split?

[dragon]

The problem you have is that it is almost impossible to self diagnose a problem with training technique....Simply because you can't see yourself doing it.You could be reading articles and trying to make adjustments that don't need to made.Unless you know you have a technique issue,you shouldn't try and address one.

If in doubt,go to a running track/club or a specialist store that sells running shoes.....These people will analyze your technique and tell you the best type of running shoes to wear and if you have performance issues.

You need to understand significance of what you're doing.....Kurz says that individuals shouldn't participate in intensive strength training until they have developed other areas of their conditioning(i believe it's something like 3000 metres in 12 mins?)...

So running alone will not mean you will be able to perform the splits.If this was the case,every marathon runner in the world would be able to do the splits-They can't.

Running will develop aerobic conditioning and strengthen/condition your muscles....Then you can move onto specific conditioning-Strength endurance,maximal strength,etc..

Dragon.

[REG]

Oh okay, that makes more sense. Yeah, you're saying that unless I do have some sort of major problem with running (i.e. a neurological disorder or coordination issue) or want to go to some sort of a track/running club that I don't need to change my running form.

So running alone will not mean you will be able to perform the splits.If this was the case,every marathon runner in the world would be able to do the splits-They can't.

What I was trying ask is that even if I jogged at a slow pace and/or with short strides, would the flexibility in my hip flexors still not be reduced compared to if I were riding a bicycle?

[dragon]

Oh okay, that makes more sense. Yeah, you're saying that unless I do have some sort of major problem with running (i.e. a neurological disorder or coordination issue) or want to go to some sort of a track/running club that I don't need to change my running form.

Not quite.I'm saying if you feel you may have issues with your form,go to someone who can advise/correct you.Don't try to self diagnose a problem which may not even be there.

The pace at which you run won't affect flexibility at all.Short strides(or even walking) won't reduce your flexibility like cycling can.

Dragon.