Fifth day workout. Keeping my heart rate at fat burn range

I have calculated that my heart rate needs to be between approximately 112 - 131 BPM. I arrived at this range using this formula.

220 - 33 =187.  187 x 60%                                     187 x 70%
                         ------------   = 112 bpm                 ------------  = 131bpm 
                              100                                                100

I have realized that to achieve this target heart rate I will need to jog on the treadmill at a consistent 5.5 mph. I was able to jog at 5.5 mph for approx 10 minutes before having to back it down to my 4.0mph fast paced walking speed. After a short break to catch my breath I was able to jog at 5.5mph again for approx 5 minutes and then back down to 4.0mph again. My entire cardio exercise from start to finish was about 30 minutes before I decided to move on to working out legs

I worked out legs today by first doing squats. Which is my LEAST favorite exercise. I realized that I will need to work on my form a bit.

Squats (45lb plate on each side and 45lb bar = 135lbs) 10 reps x 3 sets
Leg press (45lb plate x3 on each side = 270lbs) 10 reps x 3 sets
calf raises - (using my own body weight) 20 reps x 4 sets
Lying leg curls (approx 90lbs) 10 reps x 3 sets
Leg extensions (90lbs) 10 reps x 3 sets

My entire workout was approx 1hr 20 minutes. I spent about 5 minutes stretching.