High mileage runners generally speed up gradually during each days training, so it becomes part of their conditioning of the nervous system to get faster after a few miles or a few fast efforts.
Also as someone else said, the faster the race, the more warm up is needed.
It definitely takes me a long time to warm up. If you tell me to go run a tempo today, I'll groan and roll my eyes. If we're 10 miles into a run and you say how about we pick it up for the last 3 miles, bam, no trouble doing the tempo.
Well, call me anti-social but I prefer to do most of my training on my own. I suppose, if twere a nice day we could go for a bike ride together?
To get more mileage.
Been there. Done that.
I had this conversation in another thread when someone asked how you can run for 2+ hours every day and I explained that when you have a 30 minute warmup it's easy.
I do the bulk of my mileage at a pace much much much slower than I race at. It takes time to get ready for that kind of intensity. I think a lot of it now is that's just how I train, so that's how I have to warm up for races too.
Most high mileage runners aren't running much faster than 7min/mile for a lot of their running, so just getting up and running 4:30 is a bit of a shock to the system. With a good warmup though, it becomes easy to do.
For example, I would be shocked if I could step outside right now and break 4:30. If I could I would probably be sore after. However, with a proper warmup, I could run two without stopping or however many 1600m intervals at that pace. I can only speak for myself and those I know well, but none of us can just jump up and run fast.
I remember one summer my high school coach was holding a youth running camp, and I went to help out. Four of the kids wanted to race a 4x200m against me running 800m. I had just been standing around for most of the day, and didn't do any kind of warmup prior to the race. They crushed me. They got out to an early lead and ran somewhere around 2:20. With a warmup I would have won by the whole finishing stretch at least.
I only do about 20-30 mpw but my warmup routine takes around 35-45 minutes. Easy jog, drills, stretches, strides plus a few other things. The warmup can easily go to an hour if I add a couple more sets of drills.
Dan George wrote:
Once you are sweating, you are warmed up. Anything after that is a crutch or padding the weekly miles.
By this logic, I'm warmed up the minute I step outside my door. My body may be warm after a few minutes of jogging, but my legs need much longer than that to feel loose.
When you start running your heart rate spikes, and you're not fully warmed up until you heart rate can stabilize at a modest pace. If your heart rate never goes down (stays in cardio effort, etc.) then you're running too hard for the warm-up.
Longer races (i.e. marathons) take much shorter warm-ups because you start at a pace that is much more aerobic, and you need to reserve glycogen fuel cells which can be burned if an excessive warm-up is used.
I think the OP may have been referring to why when one is at a higher mileage point in their cycle, they take longer for their body to loosen up on a training run or to feel ready to work out, not why high mileage runners make the conscious decision to warm up longer. Th exact reason for this I'm not sure, but I've experienced this. I believe part of it just comes from the chronic exhaustion that occurs when you increase mileage, and it likely is a side-effect of the massive trauma your body experiences when you make a jump in volume. Your system takes longer to recover and therefore feels tight/colder longer because of the mitochondric processes taking place in your muscles. Extra stretching after each run, and stretching before the run can help you feel better earlier in the run. I know last year sometimes it would take 35-40 minutes of running before I felt like I got into a good comfortable rhythm.