Interval training and 5 mile run

The last 2 days have consisted of interval training and a 5 mile run
Interval training on Monday in the gym, it's very intense, you start by warming up for 5 mins. Then you set the speed to 17km per hour and gradient to 2% and you do 30 secs on 30 secs off. This then increases to a min on and a min off on 17km speed, then up to 18km speed for 1 min on and off, 45 secs on and off, then 2 mins rest. Then set the gradient to 1% for 15km for 2 mins and 1 min off x 2, then 8-12 x 20kms 15 secs on and off. This really is intense and gets your heart rate right up, the beauty of interval training is it increases fitness massively and gets your legs used to running to proper speeds. If you keep the above up 1-2 times a week you are on your way to breaking 3 hours in a marathon, something which I would like to do this year but not sure I have the time with lots on but we will see, you need to find the right race, conditions and timing, etc. Today I just ran 5 miles up the gym in 35.28, so quite a strong pace. With 3 days to go until 45 miles I am feeling a little tired having run the last 8 days, I think I will squeeze in a run either tomorrow or Thursday and take Friday off pre 45 miles. Last year I ran the race in 8.06, hoping to beat that this year but you never know how your body is going to react, specially after a month of boozing, this race is a funny time of year just after Christmas but great to get back into it. I am suppose to be running on Sat with my mate Elson but he may not be able to run now due to knee problems but he hasn't completely ruled himself out.... It's much more fun to run this race with someone as you can have a chat, bit of a laugh, etc but if Elson can't run I will have to go it alone.
P.S - 81 days to go