Not so weakly wandering

I've just done my walk again and this time and I mustn't be as unfit as I thought. This time I was able to walk the 3.2 km in about 35 minutes with an average speed of 5.43 km/h. I did the walk at about the same time of day and at about the same pace and now I'm here I don't feel as tired as I did before. Must have just been a bad day.