Yes I believe you really do need to warm up your brain if you want to get the best out of it.
In the process of writing a previous article about performing well when it counts I hit upon a way of explaining several theories I've yet to put to paper.
Ok the basic concept I have about your brain needing to be warmed upis that as far as I know it's because your brain functions well when blood is supplied to the relevant parts of it that need it. My guess is that until that area is well supplied with blood then it just gets by on the emergency rations stored with the relevant cell or local cells. thus there isn't much energy around and any wast can't be evacuated.
Of course you'll ask where on earth did I think the brain needed to be warmed up. Simple answer: because every time I play tennis I take say 20 minutes for my body to warm up but then I still don't play brilliantly. Then around 10 -20 minutes later I really kick in to gear and I notice it's because my brain is remembering how to deal with the conditions on the court and so it's adjusted it's timing. First off it needed a good blood supply to get the right resources (fuel, water etc) to the cells and then these cells neede dto talk to each other to solve the problem of my timing being off. Thertefore you have a time lag of say 30 minutes. If i played more regularly the time lag would be less but the need to warm up my brain would be the same.
Another way i've noticed this is when I have caffeine or when I'm over stimulated e.g. running on adrenline, I noticed that I'm much more mentally tired by the end of the day than when I have no caffeine or don't run on adrenline. My other posts on sleep and recovery talk about the brains need for rest. My point here is that each brain cell only has so much stored energy. Therefore to function at a high level like when solving a crossword it needs fuel and resources from the blood supply and it needs waste products taken away. Therefore each cell can function without the blood supply but only for a limited period. In a similar way the muscles can funciton without blood supply but they soon tire.
Every training adaptation thathappens in your body when you train for a marathon is designed to save carbohydrate because you cannot burn fat without a carbohydrate flame. If for any reason your muscle cells burn through their stored carbs too early then you won't go as far or run as fast it's as simple as that.
I feel the same happens with the brain. I beleive that caffeine is fantastic for helping you focus but it also gets you to run through your brains local store of carbs quicker than normal and so you feel more tired than usual at the end of the day. an extreme example of this has been made clear to me because I've started to get migraines in recent years. I never used to get headaches at all. So it's easier for me to figure out why I've just started. In every case I can think of it's always come at a time when I'm not sleeping very well for days on end and I have intense mind work to do. When it's lots of physical work I'm doing I don't ge ta migraine but when I have to think really hard and my body isn't reasting so my brain isn't recovering from each day then I eventually get a migraine. Therefore I'm inclined to believe that a migraine, for me at least, may simply be an example of my brain being exhausted and crying out for a rest.
Why would this hurt?
My guess is that the individual cells become inflamed which must put pressure on the intracranial cavities and eventually we feel pain. I don't know if this happens I just know that we can actually feel pain in our brain it's only when it's surrounding tissue gets hurt or pressed in some way that we feel any pain.
Why would we get sick or see colours?
Again if your brain is that tired then who knows what is going wrong with the rest of your body. I suggested in another post that a tired brain could cause problems throughout your body since your brain controls and coordinates a large part of your bodily function. It seems natural to assume that many other parts of your body will go wrong. Including your senses.
Ok I see I've moved away for my original topic. Apologies, I'll have to separate these two later. to summarise what I set out to say is that wihtout warming up your brain I wonder whether each cell or set of cells has only enough resources to function at a high level for a short while and that shortly it becomes full of waste products from the exertion. the only remedy for this is to let it rest for a time until it has recovered. Warming up the brain on the other hand by increasing it's activity in a controolled manner and not allowing either waste to build up or fuel to run out will ensure the brain can run fast for as long as possible.