Use any cardiac modality you have available at the gym that you can sustain for at least 10 min
– you can change machines every 10 min to keep variety
– must be able to track speed and time passed

Age Max HR (approx.) Zone 3 (70–80% Max HR) Zone 4 (80–90% Max HR) Zone 5 (90–100% Max HR)
20 200 bpm 140–160 bpm 160–180 bpm 180–200 bpm
30 190 bpm 133–152 bpm 152–171 bpm 171–190 bpm
40 180 bpm 126–144 bpm 144–162 bpm 162–180 bpm
50 170 bpm 119–136 bpm 136–153 bpm 153–170 bpm