I usually run w/ the HR monitor, even on the easy runs. The only time I don't use it is on some of the morning runs where I'm doubling, as that very easy 4-miler is more of a recovery run, and it's so darn slow I'm not really getting any useful info from the monitor anyway.
This week has been my down week (I can't believe it's STILL the down week), and I've eliminated the daily doubles for the sake of taking it easy. After Thursday's threshold effort, I was set for a simple 5-miler on Friday. I did go to the gym beforehand which included some moderate leg lifting although nothing really heavy. I figured, "ah, the hell w/ it. I don't need the monitor today. It's just an easy run, and being that I did some leg lifting a few hours ago I'm sure it will be a really slow one, so let's just go out and get it done."
Somehow it didn't work out that way. The first mile and a half were a bit quicker than usual and the pace held steady through the first half of the run even though most of it was uphill. Should have brought the damn monitor! Why? Because it's a leash for me on days like this - days where I should be taking it easy (7:15 - 7:25 pace) but I happen to feel like going faster. When I've got the HR monitor on I can look down and say "hey bozo, you're blowing it here. You don't want to finish this run w/ an average HR that's 4-5 beats higher than normal", and so I appropriately back off, the run goes as planned, and I'm on to the next day. But w/o the monitor, I don't have that leash. Sure I knew my HR was a bit higher than the typical easy day, but since there will be no actual record of it, it won't really matter. Sort of like that tree falls in the forest thing.
So when I turned around and headed for home (now going downhill until the last mile) and my average pace was already 7:03 I knew all bets were off. Typically the return trip on these out-n-backs averages a good 30-35 seconds per mile faster simply due to the terrain and today would be no different. I think I was hitting about 6:22 pace for a good portion of the return and I finished up w/ a 6:40 mile uphill dead into the wind. Average pace for the 5-miles: 6:46 - quite a bit faster than planned, especially considering the T-work the previous day and the lifting earlier in the day.
I guess I really just needed a down half-week this time. I absolutely MUST take it easy the next few days - I've got a week from hell coming up next week, and I think the week after is even tougher. Rest dammit rest!
Fri, 9/31: lifting (upper-A, abs, legs) stretching, rolling
5-miles @ 6:46 pace (no HR data)