Today’s training run didn’t quite go to plan.
The session was supposed to be 6.5 km, another step toward my forthcoming 10K runs. I started strongly and, for the first few kilometres, felt reasonably comfortable. But by around 4 km, I could feel myself beginning to weaken. I carried on to 5 km, but at that point decided I’d had enough and stopped rather than forcing myself through the remaining 1.5 km.
It was disappointing not to complete the planned distance, but looking at the numbers afterwards gives the run a little more context.
A Tougher Run Than Expected
I completed 5.09 km in 40:20, at an average pace of 7:56 min/km.
My average heart rate was 130 bpm, peaking at 148 bpm, and my average running cadence was 161 spm. The route was almost completely flat, with just 15 metres of ascent.
Garmin classified the session as Tempo (High Aerobic), with an aerobic Training Effect of 3.7, Impacting, and an exercise load of 104. So although I didn’t complete the planned 6.5 km, it certainly wasn’t a wasted training session. Garmin still regarded it as a meaningful aerobic workout.
That matches how it felt. I rated the effort 7/10, Very Hard, and described myself as feeling weak afterwards.
Interestingly, Garmin’s stamina estimate finished at 59%. On paper that suggests there should have been something left, but that clearly wasn’t how I felt. It’s a useful reminder that the watch’s numbers are estimates. How I actually feel while running matters more than whether an algorithm thinks I should keep going.
The Heat Didn’t Help
It was also a warm afternoon, at around 23.9°C (75°F).
That certainly didn’t help. It wasn’t extreme heat, but it was warm enough to make running feel harder, particularly as I was trying to extend my distance.
Garmin estimated my sweat loss at 740 ml, which also suggests the conditions were affecting me.
Not Every Run Goes to Plan
Garmin gave me an Execution Score of just 30%, which reflects the fact that this wasn’t the workout I was supposed to complete. I stopped short of the planned distance and clearly didn’t follow the intended session particularly closely.
But I’m not going to read too much into one difficult run.
I still completed just over 5 km in 40 minutes, and Garmin recorded a useful high-aerobic training effect. More importantly, when I realised I was fading rather than simply finding the run a little uncomfortable, I decided not to force the remaining distance.
With the 10K getting closer, I’d obviously have preferred to finish 6.5 km comfortably. But training isn’t a straight line. Some runs feel surprisingly easy, others don’t, and today was definitely one of the latter.
The plan said 6.5K. The legs said 5K. Today, the legs won.