Thought I'd pass this little bit of info along. I grew up in central Tx and lived nw of San Antonio for over 20 years. Much of that time I lived on well water that rated a 34 on the natl hardness scale of 0-10. Had to filter the sediment out but was excellent water with plenty of calcium and magnesium, both of which are required for muscles to work properly. Calcium is required for muscles to contract and magnesium for them to relax. The calcium part I knew about but I didn't know at the importance of magnesium. When we moved to Fl, I (recently) found that both calcium and magnesium are pretty much filtered out of the city water supply. About 9 months after we moved, I started dropping power. I thought it was just due to age, then last year it abruptly plummeted. I have always been very, very flexible yet I was suddenly almost rigid. Nothing I did improved the issues or power and it just kept getting worse.
 
This year's Sebring was the worst performance I have ever done there and I reaiized there was something really wrong with me, not just age related. So I started reading and talking and studying. Discovered the importance of magnesium and how cyclists are particularly susceptible to magnesium-depletion. The symptoms of magnesium deficiency mapped exactly to my symptoms and vice versa. So I searched more about how to solve the problem and started in with the solution. Took me a few weeks to find what started working for me but it did. Almost immediately I felt more relaxed. The knots in my muscles started relaxing and I was finally able to start breaking things up and gaining more flexibility and power. Did a couple of time trials the past few weeks were it was clear I was coming back. Sunday a week ago I did the 168-mile Cross-Fl ride and was beat only by Hannon-the-Cannon in his Milan racing velo by only about 15 minutes. We traded for first all the way until the last ~25 miles into a hard headwind and I watched him motor off. Primarily because I mis-mixed my fuel (I realized later) and ran low on protein after about 6 hours. Yesterday I did the annual 61-mile Spring Classic which has a lot of the really fast locals show up for a hammer-down ride in pretty windy conditions. Last year I pulled about 45 miles of the ride but was struggling quite a bit towards the end. This year I started out a bit weak still from X-Fl but after 20 miles things loosened up and I just kept getting faster, stronger and more comfortable as the ride progressed. At the 45 mile mark the fast guys (only 6 left at this point) finally asked me to bring it down a notch and several times after that I had to soft-pedal to let them recover and hook back up. My average power was basically the same as all but the two guys who spent the most time on my wheel. Past the first 20 miles I was averaging about 250 watts except when I had to roll it back so they could stay on and won all of the bridge sprints hands down.
 
I'm evidently coming back. Is good to not feel so old and weak again. So if you are having trouble making power because you muscles aren't fully releasing and can't get them to stretch out as they used to, maybe check into adding magnesium to your diet.  BTW, as I have heard from a number of sources, adding more magnesium has managed to curb my sweet tooth. Spiced food (without sugar) tastes so much better than before so have drastically cut down my sugar intake.

Funny thing. Before I discovered the cause of my power loss I had discussed it with a number of older local riders and they didn't say anything. Afterwards, I mentioned my solutions and most of them said "Yes, I've been doing that for several years!"  Evidently too much competition around here. They don't want to give up their tricks. :^)
 
If you spend a lot of time on a bike, you might discover that you can't ingest enough to keep up with what you are sweating out. In that case you might want to apply it externally also. There dosen't appear to be a big health hazard to taking a fair amount orally though it is somewhat self-limiting as your body will tell you very quickly when you are taking too much.

I didn't lose her, She moved out here when I did...
 
Oh, wait. You mean my grumpiest ridin' buddy?
 
I'm still waiting for him to come out and help me drag the tri guys around at 32mph in his fancy new M5 RailGun. I pulled a 30mph 5k TT and a 28mph 10k TT recently in mine. I'm expecting him to be riding my wheel.  But he better not wait too long, I have a new guy working his way up to staying on my wheel. He's doing better every race.

Yes. Bone density and magnesium... I didn't want to bring too much into this discussion but thanks for mentioning this.
 
One of the main supplements I use is made by Calm (there in Austin on Shoal Creek).  You can get just magnesium powder or with added calcium. We tend to get a lot more calcium in our diet and there is evidence that too much calcium is bad for both magnesium intake as well as bone density, whereas magnesium is good for increasing bone density. as this article suggests. It also touches on the topic I hinted at regarding sugar vs. magnesium.  
 
We used to get much of our magnesium from green vegetables but it appears that in many farms the magnesium has been mostly leached from the soil and is not replentished so we don't get nearly as much as we did say 50 years ago.

Lol.  I'm going to try and put it together this weekend.  I finally have a Sunday free.  I've got a waiting list of purple wanting a ride already.  Unfortunately, until I finish getting this weight off that all these meds made me put on, sprinting to 30 is all I've got.
 
Quote from goatstick on Apr 15^th, 2014, 8:51pm:

I keep trying to talk to him about his m5 build.  I need someone to dull and cable my bike like he has done.  Of course, speeds previously mentioned were on the carbent.  I should be faster on the m5

About 50 pounds from now.    what I remember most is the tunnel vision, and how everything went dark those last few minutes.  All I could see wad your back wheel.
 

Quote from goatstick on Apr 16^th, 2014, 10:51pm:

 
Had a DF rider do that on Tuesday, when another clipped wheels -- he went off the side into the grass, falling on his right side...   when he got up, he discovered the smashed banana in his rear pocket!!!!