The air felt unusually warm as I set out on the trails. Spring had finally arrived in full force, and I could feel it with every step on the path ahead.
I was still covered in chlorine from my morning swim, which wasn't helping with the sweating. I probably should have rinsed off, but there were miles to cover, and I was curious how my body would respond to a pace-pushing 21K in these conditions.
First 5K: Surprisingly Strong
The first 5K went by quicker than expected—40 minutes and 24 seconds. I was pleasantly surprised by how good I felt, especially considering I'd completed a marathon just six days earlier.
My legs had recovered remarkably fast. All week, I'd seen good sleep metrics and productive workouts. Even this morning's swim session had gone well. Things were looking encouraging despite the warm conditions and the chlorine-enhanced sweating.
Pushing Through Zone 3
The second 5K came in under 40 minutes—39:50-something. I maintained a pace that was pushing me into significant Zone 3 work, but my body was responding well.
For me, this was moving fast on trails. My heart rate distribution was showing exactly what I was aiming for — significant time in Zone 3 without pushing into Zone 4 territory for long. This kind of threshold work felt sustainable, even with the warmth.
Knowing When to Stop
As I approached 10K, I made a decision. Rather than pushing to complete the originally planned 21K half-marathon distance, I decided today was enough at 10K.
With my last big training run — a 50K — scheduled for next weekend, showing a little "showmanship" (as George would say) and ending on a high note seemed like the smarter call. The body was working well, the pace was solid, and sometimes the best training decision is knowing when to call it.
Final Thoughts
Today was a good day to push a little but not too much. With a 50K coming up, the body needed to be challenged but not depleted. A fast 10K with nearly 50 minutes in Zone 3 was the right balance—getting the training effect without demanding excessive recovery time.
The productive training status and 40-hour recovery time confirmed this was the right call. Sometimes the best run is the one where you know when to stop.
Final Stats
Here's the breakdown for those keeping score:
Distance: 6.26 miles (10K)
Time: 1 hour, 21 minutes, 3 seconds
Average Pace: 12:56/mile
Heart Rate Zones:
Zone 1: 1% (≈50 seconds)
Zone 2: 34% (≈28 minutes)
Zone 3: 60% (≈49 minutes)
Zone 4: <1 minute
Elevation Gain: 879 feet
Training Effect: 3.6 aerobic, 0 anaerobic
Training Status: Productive
Recovery Time: 40 hours
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