Reddit reviews Running: The Complete Guide To Building Your Running Program

At the risk of sounding unmotivating, I'm going to summarise a bunch of stuff from a running book I have, because these are things I didn't pay attention to a month ago and paid for it with a knee injury.

Basically, if we train too hard or overstress our bodies, it can lead to lack of motivation, fatigue, aches & pains, lingering colds, elevated resting heart rate, etc. The author advises visiting a doctor to rule out a virus, but says that otherwise it "may be your system's way of saying 'Give me a rest!' Decreases in performance are because our bodies are responding to training stresses. With a bit of rest and time you'll be back stronger than ever. It is part of the training cycle."

He says not to get worried if you miss a run or two, because taking a rest now will give you energy to run better in a few days. (Kind of like how taking a walking break gives you enough energy for another minute of running.) And he also warns that aches and pains can be a early warning of overuse injuries, and that it's better to take a couple of weeks off to heal now (if needed) than to be out for six months because you ignored the problem and decided to run through the pain.

He also give a checklist for running through an injury that I'm just going to put down here and hope it's not violating too many copyright laws...

Run if:

• it doesn't hurt to walk or use stairs
  
  
• pain/stiffness goes away during
  
  
• pain does not get worse with regular running
  
  
• stretching or icing before a run keeps the pain under control
  
  
• you are not creating chronic problems that will affect your daily activities
  
  
  Don't run if:
  
  
• you have substantial swelling/bruising
  
  
• the pain is intense and gets worse as you run
  
  
• the pain after you run is disabling
  
  
• you have upper respiratory problems concentrated in your chest
  
  
• you have to drastically alter your form in order to be able to run
  
  There's also a lot of advice on how to deal with pain during runs that mostly comes down to, slow your pace, spend more time warming up and decrease your running distance.
  
  Okay, so enough of the bad stuff. He also give some advice on how to get motivated.
  
  
• Run with a friend, pet or running group. (Personal warning from me: running with a large, leashed dog might not be the best idea to avoid injury. I started out running with my roommate's dog, but she'd get bored/tired after 15 minutes or so and I'd do the rest of my runs with tension on one side of my body as I had to keep pulling on her leash to keep her going.)
  
  
• The 10-minute rule. Pretty much what iplaywithbugs was saying. Gyourself out there, do a walking warmup (built into the 5K program) and then jog for 10 minutes (or in our case, do the first free-form run). If you feel better, keep going. If not, listen to your body and take a rest.
  
  He also suggests a change of scenery. I don't know if you run on a treadmill or not, but I've found that running outside (even though it's harder work and you have to deal with weather changes) is so much nicer than running inside on a machine. Maybe spend some time just researching a place that would be nice to run and then go check it out. Do the 10-minute run test, and if you're not feeling it slow down and enjoy a nice walk in a new area.
  
  And if all else fails, sometimes when I'm just not feeling motivated I tell myself that all I have to do is get dressed. Usually I feel like enough of an idiot sitting around the house in my running clothes and shoes that I'm out the door in just a few minutes!

This book is a terrific motivator: John Stanton, Running It contains a ton of helpful advice and even has training programs for various levels including marathon.

His Running: The Complete Guide to Building Your Running Program
https://www.amazon.ca/Running-Complete-Guide-Building-Program/dp/0143176099