Aerobic Endurance in Summer Heat – July 27, 2025

Build Phase 1 / Week 3 / Run 5 – Road to TOWaterfront 42K

Setting the Scene

Another Sunday, another heat warning. An hour before heading out, I downed a Maurten Solid 160, then began sipping Nuun in preparation for what I knew would be a sweatfest. I brought a full 500ml bottle with me on the run and tossed in a few SaltStick Fastchews for good measure, two before launch, then every 2K or so.

After 5 minutes of dynamic mobility drills, I hit the road.

My plan? Run conservatively. My reality? Let’s just say it’s a work in progress. I knew from the get-go that my heart rate would creep: full sun, high humidity, even the occasional nose scratch would spike it.

But on days like this, I defer to HR and RPE over pace, always.

🎧 Binaural tones through my Shokz kept me dialed in, steady in stride and in mind.

📊 Workout Details

🧠 Coach’s Corner

This was a solid aerobic effort in tough conditions. A few standout points:

• IF (Pace 0.83) vs IF (HR 0.74) confirms smart pacingyour internal load stayed in check despite heat.
  
• Pa:HR at 8.02% shows a slight cardiac drift, which is expected given the humidity and elevation.
  
• EF at 1.00 signals efficient aerobic output relative to heart rate, even in suboptimal weather.
  
• Elevation Gain of 148m adds contextthis wasn’t a flat cruise.
  

You executed well by leaning on heart rate and perceived effort over pace metrics. That’s veteran decision-making.

🔗 Related Reads

• 🧊 Zone 2 Easy Run – July 22
  
• 🔥 Speed Workout in Parry Sound
  
• 🌡️ Smart Devices, Dumb Trust?
  

💬 Final Thoughts

Some days, the real workout is staying smart. I didn’t chase the pace, I monitored the drift, and I kept my effort true.

Heat, humility, and hydration. This one had it all.