We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Cardio endurance training is one component of the Fitness Triad (strength, athleticism, endurance) or, as we usually divide it, strength, calisthenics, and cardio.
Unless one is a competitive runner, swimmer, biker, or rower, we believe it's good to mix up cardio exercises because just doing one improves one's efficiency too much for the cardiac stress you are looking for.
Cardio training (ie exercising your heart muscle) is like anything other muscle: you want to stress it without injuring it. That can either mean keeping your heart rate at 55-85% of your max heart rate for 30 minutes (depending on age), or it can mean HIIT cardio training with sprints. I recommend the latter for time efficiency and because it is gentler on your body.
I no longer recommend road-running, especially distance road running. A morning 5-mile jog is harmless but the main benefit is mental because few joggers get their heart rates very high. Distance runners/races (ie from marathoners to 50 milers to 100-milers) are admirable in their dedication and amazing endurance but it just isn't healthy for joints, heart, body inflammation, risk of kidney damage, and so forth. Pheidippides, who was a professional distance courier (before cell phones), died in Sparta.
Our current "Maggie's Recommended" general fitness training for the cardio component is roughly one hour of endurance cardio (a mix of elliptical, treadmill, stairmaster) keeping a solid (ie 55+% but sub-max heart rate; and 1/2 hour of HIIT cardio (30-60 second max sprints on rower, treadmill, combat bike, stairmaster, etc) with triple slow recovery times; and the mix of cardio and athleticism training in calisthenics/exercise classes.
I almost forgot to mention sports. Two hours of basketball is excellent cardio/athleticism exercise. Same for martial arts, or a tennis class.
Remember, unless you are in training for multiple hours daily, you can not lose weight by doing cardio exercise.
Is there a site you would consider authoritative regarding rehabbing a leg injury (I broke my ankle about 2-1/2 weeks ago). The bone is healing nicely, but it aches unmercifully, and I'm still not able to put full weight on it for long. Really, I just want some starter exercises that will prepare me to true rehab.
Do you folks really have time for all this working out? More power to you if you do. I do not.
Re: the broken ankle - sounds like you are too early getting weight back on it. Are you following the doctor's directions regarding keeping weight off it during the early healing? Not that it is the same, but when I had a bimalleolar fracture with a Maison-neuve addition, I had to keep off it for 16 weeks, as in now weight at all. 100% recovery was the result, and only one screw left in...
The main benefit of running 5 miles is mental because few “joggers” get their heart rates very high?
Any kind of running/jogging requires your heart to pump a lot of blood to serve the oxygen needs of those large muscles in your legs and butt plus your core, all of which is engaged 100% of the time while moving using your feet at any speed. This workload gets nearly everyone to 55% of their target rate and usually much higher. For a 30 year old this is just 104, for a 55 year old, just 90.
These low numbers are pretty easy to hit for almost anybody moving at faster than a walking pace.
There are definitely good reasons to avoid running, but lack of cardiovascular benefits is not one of them.