Low-impact cardio you can dial up as hard as you want.
Keep a smooth, round pedal stroke and don't bounce in the saddle when resistance climbs.
The bike delivers steady cardiovascular work through a smooth circular pedal stroke, with the resistance dial letting you sit anywhere from easy recovery spinning to lung-burning intervals on the same machine. Because there is no impact, it trains your engine without the joint cost of running, which is why it pairs so well with heavy leg training. It earns a place for warm-ups, recovery days and serious conditioning alike.
For heart and lungs, absolutely, effort is effort. You just have to bring it, because the bike will happily let you coast in a way a run will not. Use resistance and pace targets to keep yourself honest.
Set it so your knee keeps a slight bend at the very bottom of the pedal stroke. Too low grinds your knees, too high rocks your hips in the saddle. That one adjustment fixes most bike complaints.
Both work, for different goals. Steady moderate riding builds your aerobic base and aids recovery, intervals push fitness harder in less time. Most people do best mixing the two across the week.
