Higher run cadence

I found that I was more efficient running with a higher cadence but quicker with my normal stride but I tired sooner for the same effort. I used to listen to my metronome ( an application/ device on my iphone for keeping your timing when playing the guitar) set on 180 bpm and I would run to that and make sure I was striking at the same time. Terribly boring but it works - I find that I know run without it at a cadence of about 88 but it's a lot higher than what it was. I am happy with my progress since focusing on this.

I think I remember reading that a higher cadence is recommended because at a lower cadence runners tend to over-stride instead of striking the foot directly under their center of gravity.

that's just an opinion and not based on the available evidence which suggests there isnlt really any optimal cadence since it is a function of your stride lenght, fitness, speed, natural gait, biomechanics, terrain where you run, etc. There are elite runners on the 80-85 cadence x foot while others on the 95-100 and yet others around 90. 

I would be careful about changin anything in your run style just for the heck of it and *if* you still choose to go that route do small changes and see how your body responds. As you noticed, some of your muscles are not used to the work induced by running in a certain way because you have simply run in your natural gait for many years; hence doing drastic changes can easily lead to injuries just because your muscles are not trained to handle the work.

The low rpm ride is also nothing but an opinion as rpms is a function of torque and rpms, if one goes up the other one does down and viceversa and that is more a result of your power output, genetic make up, terrain, fitness, fatigue, etc.

I personally believe we all are different and respond different to training hence trying to match all athletes through a "one-size fits all" mold is a risky practice.

I shortened my stride and increased my cadence after ITBS struck me at Boston. I think I run slower but I've had less injuries. Not sure what this means for you. I was a runner before I came to tris.