Many people choose running as a primary exercise because they think it’s something easy and free. Not only do they spend a lot of time hurting themselves with improper form but they also tend to only run, foregoing other types of workouts. This is a problem because it only works a few muscles in a limited direction, and these are the same muscles that we use anyway whenever we walk!
Myth #1: Running is easy
Proper running form does not come naturally.
In fact, the incidence of running-related injury is high. This is regardless of how quickly you ramp up running intensity, according to a recent study a graded training program for novice runners that was centered on reducing the risks of injury failed to prevent injuries. About 20.8% of runners that were in a graded training program got injured, compared to 20.3% of runners that got standard training. The study disproved the most frequent advice given to novice runners, which is to increase running intensity (duration and speed) by no more than 10.0% at a time. 
Despite countless studies, sports scientists are still unsure what training errors are most likely to lead to which running injuries because sports are so complex. Lastly, maintaining proper running form is hard for many of us because we’ve been running in bad form for our entire lives.
Here’s a video that goes over proper running form in a simplified but step-by-step manner
Myth #2: Running is free
The majority of Americans run on a treadmill, for which they either have to buy a gym membership or the treadmill itself. To complicate the issue, people don’t generally realize how important it is to have proper running shoes. This has to do with the high-impact of running that can easily lead to injury. For example, I did not go to a running-specific store to get my walk judged and appropriate shoe recommendations until after I had developed a case of runners knee, which still bothers me two years later. The time commitment of going into a running-dedicated store is worth the investment to get customized advice because everybody’s feet are unique so you can’t just pick out the same running shoes as your buddy. Also, sneakers should be changed more often than I had ever imagined, it depends on the brand so make sure to do your research! Good running shoes easily run $60, which still may be cheap compared to other exercise equipment but running is definitely not free.
An elliptical machine can be the solution to doing workout similar to running, but much lower impact. Also, there are many introductory offers for fitness classes, whether they are sport-specific, bootcamps or gyms, where you can learn new moves. Either way, if you just run or do cardio workouts exclusively, you end up hampering your potential health and strength wise. Consider new kinds of workouts, like weight lifting, to reduce injury risk and amplify the effectiveness of the time you spend on fitness.