College Strength and Conditioning Coaches
Question on isometric training
I just simply did a search on the Journal of Strength & Conditioning Research for isometric training power. The first thing that came up had some information on there. The first study is plyometriv vs isometric training influences on tendon stiffness, which indicated that isometric training with iso's does in fact have a positive effect on tendon stiffness. It was a trend towards significance, and not statistically sig, so you could have an argument there, but so does he. I didn't see anything in the methods, but I just breezed through it. Anyway, you can try a search on pubmed too, for whatever reason I couldn't get onto their site though just a minute ago.
You may be able to reach some sort of compromise with him on something. Find out why he wants to build the mental toughness with iso's. If it's just because they suck, you may find some other way. I'm not sure if there are time constraints on high school workouts like there are on college, and if so, what those are, but I can find other ways to spend 10 minutes to build mental toughness. Various things that work strength endurance, etc (think strong man stuff, ropes, etc). They all suck, and thus must make you tougher, according to the way he thinks.
Anyway, good luck!
Doing a quick search this article may help to support your claim a bit. Other than this you can more simply explain that a 2 minute isometric hold in a squat position is really not training strength and power. Your just fatiguing the muscles and more likely improving a strength endurance aspect of the muscles as opposed to a emphasis on power. Personally, if I was in your shoes, I would have asked the coach why he was suggesting that type of training and where he is coming from. If your the strength coach with a certification, a coach should have to explain to you why he/she may want to change something in the program, with evidence for support, not the other way around. But that is just my personal opinion. Every setting is run differently but thankfully in my University setting the AD supports us 100% because he understand that were the ones with the training and certification. Like what Bryan said, you may be able to compromise and keep him happy by doing some of that stuff on a light day in the program and lower the weight to have a more strength endurance effect. Hope this helps and good luck.