Elitetrack: Sport Training & Conditioning

Abstract The present study aimed to investigate the effect of isometric squat training on human tendon stiffness and jump performances. Eight subjects completed 12 weeks (4 days/week) of isometric squat training, which consisted of bilateral leg extension at 70% of maximum voluntary contraction (MVC) for 15 s per set (10 sets/day). Before and after training, the elongations of the tendon–aponeurosis complex in the vastus lateralis muscle and patella tendon were directly measured using ultrasonography while the subjects performed ramp isometric knee extension up to MVC. The relationship between the estimated muscle force and tendon elongation was fitted to a linear regression, the slope of which was defined as stiffness. In addition, performances in two kinds of maximal vertical jumps, i.e. squatting (SJ) and counter-movement jumps (CMJ), were measured. The training significantly increased the volume (P<0.01) and MVC torque (P<0.01) of the quadriceps femoris muscle. The stiffness of the tendon–aponeurosis complex increased significantly from 51±22 (mean ± SD) to 59±24 N/mm (P=0.04), although that of the patella tendon did not change (P=0.48). The SJ height increased significantly after training (P=0.03), although the CMJ height did not (P=0.45). In addition, the relative difference in jump height between SJ and CMJ decreased significantly after training (P=0.02). These results suggest that isometric squat training changes the stiffness of human tendon–aponeurosis complex in knee extensors to act negatively on the effects of pre-stretch during stretch-shortening cycle exercises.

RJ- you posted this on CF

Yes, the load present in this type of training is very low, but not much load is required to cause occlusion within a given muscle group. This state of occlusion generates a hypoxic environment, and in a hypoxic environment, the ST fibers have no way to generate fuel. If they have no way to generate fuel, they cannot contract. This leaves only the FT fibers to do the job.

I have a very limited knowledge on this stuff so if these are stupid questions then just tell me, but these posts have intrigued me.

1: If isos recruit fast twitch fibers better, aren’t the lifts still going to be counterproductive to force production during sprinting because you are eliminating the firing patterns by making it a hold instead of a movement?

2: if that is the case, then shouldn’t isos be primarily done in early offseason to recruit the fibers with ample time to train the newly recruited fibers properly? Is that even how it works?

Did that make sense? It’s been a damn long day.

00Scoots - 22 April 2008 06:48 PM

RJ- you posted this on CF
I have a very limited knowledge on this stuff so if these are stupid questions then just tell me, but these posts have intrigued me.

1: If isos recruit fast twitch fibers better, aren’t the lifts still going to be counterproductive to force production during sprinting because you are eliminating the firing patterns by making it a hold instead of a movement?

2: if that is the case, then shouldn’t isos be primarily done in early offseason to recruit the fibers with ample time to train the newly recruited fibers properly? Is that even how it works?

Did that make sense? It’s been a damn long day.

Don’t worry, your questions aren’t stupid.

1) No, there is little difference between an isometric and a regular contraction in terms of the neural signals. But if you want to get right down to it, long duration isometrics are actually prolonged and extremely slow eccentric contractions. Now, eccentric contractions do have different recruitment patterns than concentric and isometric contractions as the FT fibers are preferentially recruited during the eccentric. If anything, this is actually another upside. But to answer your question, isometrics will not damage firing patterns. They are not a system in themselves, but they’re a useful supporting method, just like weight training or plyos.

2) I’ve found that ISOs actually help me recover faster than anything else I’ve done. For this reason, along with the fact that they won’t throw off firing patterns, they can be done year round.

If you have any other questions, just ask.

K, putting long duration isos aside for the moment… Mike, do you know much about the inno-sport system, and what do you think about it?

I can’t say I know it in and out but I did train someone who trained under Shroeder (I know it’s not exactly the same but obviously more similar than most training systems) who gave me some insights although that was a long time ago and I have read a little of the now-obviously-bogus DB Hammer stuff.

I think there are some interesting concepts in the inno-sport system but from the little I’ve read many of its practitioners seem to be somewhat dogmatic (almost to the point of being snobbish) and despite claiming to be the new wave in science backed training, they often ignore what research as well as dozens of years of anecdotal coaching experience has to say about far less sexy training means (like plain ole’ squatting). I will say that I use some similar concepts in my training plans but they are never the sole focus. For example, I tend to give fairly large roles to isometric and eccentric strength and power development (although no long holds) and fast coupling / switching mechanisms. In my opinion, there’s a time and a place for almost anything in a well rounded training plan and the inno-sport stuff is no different in this regard.

It seems like you’re critiquing it mostly based on exercise selection, but what do you think of the use of drop-offs to manage fatigue? I think it’s brilliant, because it makes alot more sense than just picking a random number for the amount of sets. Plus, the system itself can be applied to several different training “styles”. If you like to use squats, then you can do squats to whatever modality, bracket, and training percentage that fits with what you are trying to train.

I think the system is written off because of the acronyms and the other oddities, but if used by coaches of your caliber it could be very effective. What about it makes you think that it is “obviously bogus”?

Beau

How do drop-offs make that much more sense than just picking numbers based on observations?

You have no idea what amount of fatigue is going to be best in response to that workout. Will 1%, 5%, or 7% be best on any given day?

Looking at sport results, we can see many people seem to “drop-off” only before performing their best result of the day. Look at LJ/TJ/and various throws.

And how do you use drop-offs once you get to competition or are planning for a competition? If you know you need to have the fitness to run 3-4 rounds in at least two events, then what? Do you continue to set arbitrary drop-offs when you know you need to get to another level of sports fitness and readiness?

I just fail to see how drop-offs in the way they are used by DB/Inno/WGF are in anyway more logical than using good eyes and going by feel--you’re still picking an arbitrary level of fatigue to stop and use.

I see where you are coming from, but think of it this way. If you’re training a sprinter, then doesn’t it make sense for them to train at near-maximal velocity? Using drop-offs you know that all of your reps are being performed within a certain percentage of maximal velocity. You can also manipulate the drop-offs to achieve certain effects. If you are training for maximum speed / strength / power you use a lower drop-off, and if you’re training for work capacity, you use a higher drop-off. They already have set drop-off %s to use for different situations, so you can just tweak them to what works best for you.

Believe me, if you try it you will find that it works very well.

I know that if I went by that logic, I would never run more than one or two reps in training because I’m so far away from my race times anyway.

I don’t think many people need to be told when they’re running slow and when they’re running fast. Yeah, you may not know the exact time in training, but if you’re fatigued and slogging out crappy reps, you know it.

Arbitrarily choosing drop-off percentages does nothing but change how you’re measuring and deciding when to cut things off. If one coach uses their experience and their eyes to decide when the athlete should stop and another picks a percentage drop-off as the point for where they should stop, it’s pretty ignorant to say using the drop-offs is brilliant because it may in fact hinder things if that is your main concern.

And you are saying you can manipulate the drop-offs. Well no crap, that isn’t the question. No one knows how much of a drop-off or fatigue or whatever will generate the best response from any given workout. No percentage is best all the time or even most of the time and effects will vary workout to workout, exercise to exercise, etc.

What have your results been with it? Talking absolute improvements. The results we’ve seen from the drop-off system so far have been 10.3x to 10.4-10.5x, 12.1x to 11.71 in a c2 year period, and some others. Not to say it can’t be used, but it’s how its used as drop-offs in themself are just a tool and certainly not brilliant.

I’m not a fan of quantitative dropoffs for sprints. I have played around with them but ultimately there’s just too many variables that come in to play to use them effectively (other than as a placebo benefit) IMO. I frequently cut off workouts when I feel that a detrimental performance dropoff has occurred or is about to happen but I don’t think using timing gates to do it is the best way and I think it has many flaws. It sounds great and very scientific but it’s like trying to measure the power of a car by the sound of it’s engine. There’s some relationship there and in many cases it’ll work (like with a mustang) but it’s just as likely to not work (like with an audi).