So sometimes I get out of work, and my legs just don’t want to cooperate in terms of running or doing significant cardiovascular work. So how to get my cardio in and keep my heart rate above 130 for one minute intervals at least 10 times? I find that if I try and grind it out by running fast on days like this, I get discouraged. Its not my heart rate and shortness of breath withe exercise that limits my running on days tike this, it my legs that just feel tight and fatigued. For example, every Tuesday I am in the clinic all day, on my feet seeing patients. I have been in practice for 25 years, and I see 50-60 patients on Tuesday. So my hack is when I get on the treadmill, I get my heart rate up by running slower on a steep incline, say 5-8 degrees at 4 mph. I usually cycle every 2 minutes, meaning I run at 4 mph at 8 degrees incline, then 4 mph at 1 degree for 2 minutes. I repeat this cycle for 40 minutes, and get a nice work-out. I vary the incline on how I feel. Usually, I will start off at 5 degrees incline, but as I run longer and feel better, I increase the incline on my higher intensity segments. Try it, it really does work.