What is the exercise that burns the most calories aside from running?

I have plantar fasciitis and i cant run right now so im scared i’ll lose conditioning while on this break, so i have to find another exercise for now to stay in shape without damaging the foot any further. Also I dont have acces to a swimming pool so i can’t do that…help?

What is better exercise running a mile or doing stairs for a mile, which burns more calories?

What is better exercise running a mile or doing stairs for a mile, which burns more calories?

What kind of exercise burns as many calories as running?

I’m trying to lose weight, and I’m getting tired of running everyday to do so. But running burns so many calories, so I feel guilty just walking because then I’m not burning as much and therefore not losing as much weight. I’ve tried riding a bike, but I’m bored of that, too. Is there some kind of exercise that burns as many calories as running .. something new I can try?