I was a runner ("jogger") for 35 years and only stopped when an unrelated injury put my hand in a cast for 6 weeks and I couldn't figure out a way to run without compromising the injury.
So I did some research, and concluded that running is not actually so good for you. It isn't even all that great at weight control (a constant issue for me). The harm to joints outweighs the minimal cardio benefits, and I actually think running 3-4 days per week (doing nothing else) inhibits muscle growth. Show me a marathoner who does not look malnourished.
Any good fitness regimen includes three essential parts: resistance training, flexibility, and some form of "cardio." And of course, no training regimen can do you any good unless you actually do it.
According to what I have found, the best "cardio" is progressive interval training. And like it or not, the best tools for progressive interval training are a treadmill and/or a stationary bike. Typical regimen would be (i) jog two minutes, then walk two minutes, (ii) run for 1 minute at a slightly faster clip, then walk until fully recovered (60-90 seconds); (iii) run faster for one minute, then walk until fully recovered. Repeat, increasing the speed each time, until you reach a speed where you cannot continue for the full minute. Walk for a minute or two to recover, then stretch. The whole workout will take around 15 minutes, and is much more beneficial than a half-hour run. This workout can easily be converted to a good stationary bike. Max heart rate for the last interval should be at or near ((220 - age) times 0.85. For me it is ((220-66) * 0.85 = 131.
Walking is better for weight loss than running, although obviously more time must be invested. In either case, hills enhance the workout greatly, although running downhill is hell on your knees. Running burns sugar and carbs; walking burns fat.
Resistance training should include some reps at maximum effort, and should conclude with multiple reps (at least 20) at a light weight
