Revising plans

What : brisk run
Distance : 5 miles
Time : 35:56

Good dinner out night last night with MrsW. The sticky toffee pudding was wonderful but a bit late to bed and not a good nights sleep having eaten so late. The run was supposed to be brisk (or about half marathon pace) which I would have liked to have done outside, but I didn't trust my digestive system after all that rich food. So it was the treadmill again.

Did a mile warm-up got off reset the HRM etc and started off on my 5 mile brisk. Not a lot more I can say really My HR only averaged 158 but was beginning to drift in the last mile as it went from 161 to 164. But neither of these are anywhere near the 171 which the upper limit.

Perhaps I'm not pushing myself hard enough? Don't suppose it really matters I'm on track for a sub 3:30 that is my main priority I'm not going to jeopardise that by pushing hard now and getting injured.