I hate running so much that, when I was younger and had to choose a more agreeable form of fitness, I took up Chinese Kickboxing (Sanda). Yes, I prefer getting kicked in the face to running, about the most intolerable form of exercise I know.
I wish I could get that joy from running, but my entire body hurts, from the inside-out, when I do it. It made it hard to get good cardio training when I was training for a fight, I usually substituted lots and lots of swimming, which I find far more enjoyable and seems to do a better job of training cardio without injuring joints you'll need later.
I love running and agree swimming is better for the joints, but the cardio workout I get from swimming is not comparable to what I get from running. While I'm a very good swimmer, it's harder for me to reach the same level of exercise intensity in water versus on land.
With the recent biking renaissance here in the US (which means easy availability of high-quality parts and more widely-adopted standards for equipment) and due to my consistently sustaining muscle injuries after 30 years of running, I've turned to biking to maintain cardio.
Cycling is much easier on the joints and easier (for a runner like me) to achieve and maintain intensity, though it does have its hazards. (Accidents will happen.)
Back on topic, I don't get the same kind of "high" biking as I do running. The biking high feels more adrenaline-based, laced as it is with anxiety, aggressiveness, and irritability. Running for me induces a more blissful harmonious state of consciousness than does cycling.
Somewhat related as you mentioned swimming and cycling, but both of those forms of exercise can lead to decreased bone density unless you are supplementing them with walking or running. Cyclists in particular often have lower back problems from sitting with their back in a weird position for long periods of time. That's not to say they aren't good forms of exercise, but it is also good to get some sort of impact based exercise as well (like running or walking). Of course too much running is probably bad for your joints and anecdotally I know a lot of older runners with chronic injuries, so it's tough to strike the right balance.
What kind of cycling do you do? I don't like riding near cars, so I do almost all of my riding in parks and forests. When I do ride around cars, I can never maintain a good pace. I'm constantly stopping for intersections.
On the other hand, when I'm on a trail, The anxiety of contending with cars is gone, and I can keep a high pace for much longer.
The best is mountain biking on single track. No cars, no sign of civilization, just wilderness.
I find mountain biking also is also a bit better for core and upper body fitness than road cycling as there is a lot more variation in movements eg obstacles, drops, grade changes etc. Apparently the extra bumpiness also help avoid the bone thinning effects of road cycling - but that is probably completely negated by full suspension bikes these days.
Alas due to circumstances, I've swapped MTBing for cycle commuting. I can no longer say I enjoy riding bikes - but it still beats public transport or being stuck in traffic.
> I wish I could get that joy from running, but my entire body hurts, from the inside-out, when I do it.
Running doesn't have to hurt! As long as you do it regularly and increase the length of your runs gradually.
> It made it hard to get good cardio training when I was training for a fight
Common alternative (or complement) to running in fighting sports is rope skipping.
Swimming is great but requires more technique and training discipline to be as efficient a cardio training. Plus you need a swimming pool nearby that isn't too crowded.
I wish I could get that joy from running, but my entire body hurts, from the inside-out, when I do it. It made it hard to get good cardio training when I was training for a fight, I usually substituted lots and lots of swimming, which I find far more enjoyable and seems to do a better job of training cardio without injuring joints you'll need later.