Spicy Intervals in the Cool Morning Air - August 15, 2025

Build Phase 2 | Week 3 | Run 3 — My Road to TOWaterfront 42K

Wide, vintage comic‑style illustration of a middle‑aged Black runner wearing a blue tank, black 7‑inch shorts, blue/gray cap, Shokz Open Move headphones, Garmin on the left wrist, and blue Altra Experience Flows, sprinting across the frame. Behind him, a TrainingPeaks‑style blue interval bar strip spans the width, with a faint Maurten Mix 160 + Gel 160 fuel‑timing line graph layered behind the bars.

Introduction

Today’s Build Phase 2 | Week 3 | Run 3 had a bit of everything: cool morning air, an alternating 2-min-on / 1-min-off speed set, and just enough spice in the legs for a final push. Coming in with the dew point comfortably under my recent heatwave experiences, I was ready to see what my legs could do without the humidity dragging me down.

I did good!

Pre-run fueling was textbook: 500 ml Maurten Mix 160 starting an hour before, topped up with a Gel 160 just before my dynamic warmup. Two SaltStick caps and some Nuun rounded out the pre-launch prep.

Once rolling, I hit my warm-up and strides cleanly, then dove into the 15-minute alternating set: 2 min in Z5, 1 min in Z1, repeated five times. I took intra-interval walk breaks when needed, but still kept pace honest.

I’m not sure whether it was the Marcora effect (Motivational Intensity Theory), those quick walks, or the Maurten magic, but I had a little extra snap for the final hard rep. Cool down felt smooth, and I walked away satisfied.

Metrics Table

Metric	Value
Duration	0:34:08
Distance	5.41 km
Avg Pace	6:19 / km
NGP	6:07 / km
EF	1.83
Elevation Gain	103 m
Elevation Loss	109 m
Avg HR	149 bpm
Max HR	168 bpm
Pa:HR	5.30 %
hrTSS	36
rTSS	54
IF (pace)	0.93
IF (HR)	0.76
VAM	181 m/h
VAM W/kg	0.91
Cadence Avg	166 spm
Cadence Max	186 spm

Coach’s Corner

This was a well-executed speed session under much friendlier environmental conditions than earlier in the week. The alternating 2 min Z5 / 1 min Z1 format kept your cardiovascular system challenged without extended lactate buildup.

EF at 1.83 is solid for a speed session-higher than your recent tempo and long runs, as expected given the intensity. Pa:HR at 5.3 % is well within range for a controlled workout, confirming that your pacing and recoveries were balanced.

The walk breaks didn’t detract from the overall intensity-in fact, they may have allowed you to sustain a sharper kick in the final interval, which is a good sign of muscular resilience. Given your consistent cadence (avg 166 spm), you maintained form under stress.

Conclusion

Today felt like a breakthrough on multiple fronts: cooler air, effective pre-run fueling, and a well-paced execution that left something in the tank. Speed and control are starting to merge into a confident, sustainable top gear.