Former Bad Ass
Theoretically, the runner shouldn't have a problem hitting the correct GMP effort on race day. I agree with George. The body does not know numbers, it knows effort and you ran at similar effort. Of course nothing is exact but I'll bet you a runner that ran all the MP runs on pace in 100F will have problems hitting the GMP in 45F because he exceeded the effort several times and overworked the body.
For the sake of discussion let me throw this hypothetical out there based on your answer: a runner is unable to train for a significant time at GMP during training due to heat but the event is expected to be run under ideal conditions (45 degrees for example), should the original time goal be thrown out the window, or will the adaptations to running in heat translate to that of possible GMP on race day?
Damaris
Are we there, yet?
Are you also referring to a reduction in total miles run? Do you mean GMP for ideal conditions or GMP under summer training conditions?
2024 Races:
03/09 - Livingston Oval Ultra 6-Hour, 22.88 miles
05/11 - D3 50K 05/25 - What the Duck 12-Hour
06/17 - 6 Days in the Dome 12-Hour.
No, not a reduction in mileage, I meant a lack of training at goal marathon pace due to conditions like heat and/or humidity in July and August, for an event that may possibly be run on a cool morning. Like you might find some years for the Air Force marathon in September for example.
Couldn't say from experience since I've never trained at GMP. When I checked my race log, most of my best and fastest marathons have been in the spring or winter months, only one in the fall when I would have been doing much training in the summer heat and even that one was in November so there was a couple months training in cooler weather anyway. Back then the heat didn't keep me from racing frequently or running high quality workouts, but those didn't include GMP runs. I ran a lot of intervals and shorter races in the 5K-20K range.
If you were racing in that weather on that course, what would your GMP be? As has been pointed out many times, the body doesn't know distance and by implication pace, it knows time and intensity or effort. You'd adjust your pace if you raced under those conditions, so why wouldn't you adjust it during training.
If race day conditions were 85 and humid, at this juncture I would DNS and scramble to find another race the following weekend. (Knowing that even baseline BQ would be a chore, let alone BQ-10. And baseline BQ won't cut it this year.)
Hopefully the effort was the right kind of stressor, because rarely have I totally crapped out during a LR.
flashlight and sidewalk
This is a great topic by the way.
I question this a little bit. If the intensity and effort are kept the same but result in a slower pace than something has to be different. If we assume that you maintain the same cadence, than the difference has to be your stride length. Your body certainly "knows" range of motion. With a bigger range of motion (longer stride) wouldn't your muscles get worked a little differently? I don't know if that is important or not...just playing devil's advocate here
Our high school track coach was big into "muscle memory". He'd have high school kids getting "towed" with bungy cords by college athletes. The result was running faster than you ever possibly could on your own (or possibly falling on your face). I guess that's something that has stuck with me.
**Ask me about streaking**
This is a great topic by the way. I question this a little bit. If the intensity and effort are kept the same but result in a slower pace than something has to be different. If we assume that you maintain the same cadence, than the difference has to be your stride length. Your body certainly "knows" range of motion. With a bigger range of motion (longer stride) wouldn't your muscles get worked a little differently? I don't know if that is important or not...just playing devil's advocate here
Your body is expending energy for other functions like keeping you cool (or warm in the winter), energy that is no longer available for running. The body is also less efficient at higher or lower temperatures so there's more energy "wasted". The result is a slower pace for the same perceived effort.
I don't disagree with that. I agree that you will slow down.
The "mechanism" of the slow down has to be stride length or cadence. (stride length x cadance = pace)
I would venture that you probably wouldn't slow your cadance...that's an assumption (I think it's a fair one)
That leaves stride length as the main physical difference between GMP and GMP+heat (there are physiological causes, wasted energy, etc.). If you take a shorter stride (because of the physiological reasons you mentioned), than you are working your muscles a little bit differently (does this make much of a difference? I don't know) then you would if you were taking a longer stride. You would also be stretching tendons and ligaments a little less...working in a slightly different range of motion.
I guess this probably doesn't make much of a difference in the grand scheme. People don't run GMP for the "range of motion" benefits.
I don't disagree with that. I agree that you will slow down. The "mechanism" of the slow down has to be stride length or cadence. (stride length x cadance = pace) I would venture that you probably wouldn't slow your cadance...that's an assumption (I think it's a fair one) That leaves stride length as the main physical difference between GMP and GMP+heat (there are physiological causes, wasted energy, etc.). If you take a shorter stride (because of the physiological reasons you mentioned), than you are working your muscles a little bit differently (does this make much of a difference? I don't know) then you would if you were taking a longer stride. You would also be stretching tendons and ligaments a little less...working in a slightly different range of motion. I guess this probably doesn't make much of a difference in the grand scheme. People don't run GMP for the "range of motion" benefits.
I think you're overthinking this. Why does it have to be one or the other? I expect it's a combination of the two and highly dependent on individual response to the conditions. You aren't going to be able to overcome the effect by playing around with the supposed mechanism. You aren't going to get as much power in your stride, so stride length should decrease. Your reaction time may increase causing slower turnover and cadence. But mechanism, as you are looking at it, is not cause.
In my experience, my cadence has stayed the same no matter the weather (100F, 50F), so it has to be stride length. Maybe the body shortens the stride length when it's harder to power up (high dewpoint, high heat)?