40 minutes

I used to only run cardio (albeit on the cross-trainer) for 19 minutes at a time. I would burn my legs and my arms for 19 minutes, hitting my heart-rate up to 170 and keeping it there.

As part of my (sporadic) marathon training, I have begun to train for 40 minutes. There have been times in the near past where I have attempted to even run at only 40% resistance on the cardio and struggled immensely. The spirit, the body and the will have simply not been there.

Today, though, I hit a 40 minute cardio with remarkable ease. My heart-rate was 160 throughout the first 20 minutes, and hit 180+ for the last 20 minutes.

The thing is, and this surprises me, I felt comfortable. My heart-rate meant I should not have been comfortable.

The truth is, my body will struggle with the impact of 40 minutes of running. But the cardio doesn't seem too much of a problem.

And so I have the 10k in two days. I wonder...