It depends, that was just climbing. On a 40 min run it's doable without anything affecting the heart rate significantly, I say that because it's just a calculation following heart rate.
In truth, the more fit you get, and this is talking cardiovascular fitness + endurance and strength in your legs, you can burn more calories within each time category. So someone starting out and pushing 70-90% of their maximum heart rate can burn 400 30 mins, then over time, like a year of being consistent and increasing resistance where needed, they can easily expect to damn near double that, if not 1.5x.
I believe in gamifying things to increase consistency, it's easy for me to just do things because I come from a wrestling background but I can easily see how cardio is boring as fukk. In that case I recommend anything that attempts to gamify the effort, giving you badges and reminders to get back in it and even providing a virtual experience.
So if a peloton bike is too much I would go with this
With that, you can do the peloton exercises, or you can try Zwift, or sufferfest or just any bike related app.
Something I plan on getting into is online competitive rowing, and things you can look into for rowing would be the WaterRower + Ergatta, which translates power data and provides a gamified experience. That's not the best rower, the best rower is easily the Concept2, but that thing is loud as hell and beginners would find it boring as hell.
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But I incorporate all of that with tracking on my Apple Watch (fitbit or others), and I use Cronometer to track calories. Also, a Polar H9 for HR tracking.
edit: Let me know if that Amazon link doesn't show up, my adblock hides those type of links.
status.
Im a grown man. fukk I look like eating all that goofy shyt. You prolly still play the games on the back of the box & collect box tops 
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