Running on the treadmill

It always takes me a while to get going on the treadmill - I start walking at 3.8+ mph then after 5 mins speed up to 4.2 to run,increasing as and when I feel like it - however my legs always feel heavy until I finally get into my stride about halfway into a 30 min run.

I was only able to do 50 mins on the treadmill tonite before the cool down kicked in - think this is to stop people overdoing it - I actually only ran for 40 mins. Was sweating and my face was probably red but didnt look in the gym mirror.

Looking forward to ligher nights and warmer weather so can run outside again after work especially when on late shift (10am-6pm)