FB Fit day16

I’ve got upper body cardio. I love boxing, I have a question though Daniel or Kelli, how do I keep my heart rate up during this type of session? Even if I go faster I can’t go to more than 130 unlike the hi impact jumping ones where I can go 150 to 160 and I can maintain it through out the workout. This low impact ones and the strength training one I find hard to keep my heart rate up and I’m using 30lbs and 20lbs each hand depending on the exercise. My heart rate is not up but I do feel them muscles especially the chest after that extra credit burning.