“I visit my fitness club 5-6 times a week and ALWAYS do a 9-11 minute HIIT program on an elliptical. A quality heart rate strap and phone app will maximize your efforts.”
I have the Polar H-10 and run the app on my phone.
I plan HIIT once per week, but weight training gives the same cardiac effect. After warm up this morning, I got to 142bpm just doing dead lifts.
Everyday I do HIIT on the elliptical first followed by weights & machines.
I use the Polar app - an excellent read out/summary.