You might be expecting some discussion about periodization, overtraining, or the importance of pre-race tapering to follow such a title. But i'm interested in commenting on a something that i've experienced recently on a much shorter time scale than months or even weeks....think minutes. [Note - it's probably debatable as to whether the idea of 'peaking' even applies over the time scales of individual workouts. The system that encompasses athletic achievements might not be scale symmetric, putting it in the same category as most physical systems. I'm sure Galileo would know the answer.]
When i say I've peaked too soon during a single workout, i'm really indicating that i failed significantly during it. For example, last tuesday during my run I intended to perform seven work intervals at a sub-seven minute pace. I only made three. The remainder of the intervals i had to drop the speed significantly - to an eight minute pace - and even that was challenging by the end. Ouch.
Why did this happen? Well, i can think of a few reasons - 1) I was over-reaching. 2) I was mildly ill/malnourished/dehydrated going in to the session. 3) I was somehow mentally unprepared - i.e. i had an ill will ;-)
After the workout i reviewed my training log and found, as expected, that i had completed the same workout several months prior while training for my jaunt on the mantario trail. If i was over-reaching, it meant i was also less fit than i had been then. I may have also been suffering from #2, but based on my records some of my best training sessions have come when i had to squeeze them in, knowingly hungry and slightly dehydrated. Perhaps i also experienced some lack of will - however i'm pretty sure that if i hadn't dialed back the pace i'd have ended up on the floor during the next interval or quickly thereafter. I wore a heartrate monitor so there was no doubt that i was physiologically well up where i wanted to be in terms of training zones (HR stayed above 180 most of the time, peaking around 193 - definitely Z4/5), and this knowledge helped curb some of the immediate disappointment I felt after realizing i wasn't going to make the workout as planned.
The main reason i'm chosing to write about this seemingly insignificant event is that as i've been training Dave, he's occasionally missed paces or 'failed' to complete workouts as prescripted and has always seemed pretty bummed. I'd had a long string of success until recently (maybe i'm setting the bar too low for myself!) and so didn't really 'get it' in a sense - but now i think i do. While it can be depressing if you aren't prepared i think the truth of the matter, especially in a one-off situation like mine (fingers crossed) and most of Dave's, is that it's a good thing.
Failure means you've worked to failure. 'Peaking too soon' means you've at least hit the peak. Unless you're really dealing with a motivational issue (with genuine reflection this ought to be apparent), then you have pushed the edge of - or at least approached - your physiological limit. Not only that, but you have done so early in the workout and so get the added bonus of exploring the mental headspace that can be so crucial during race day. Because lets face it, when it comes to running an endurance event on only three hours a week of training, you're almost certain to feel like you've hit your 'peak' LONG before the finish line is even a speck on the horizon.
On the off chance that you keep 'failing' during your workouts, however, it's probably time to suss out the bigger issue or, if you're Dave, get a new trainer.