Us runners are the WORST when it comes to exercise exclusivity.
How do I know this? Because I totally was you and sometimes still am you.
I think runners are the funniest breed of athletes because all we ever want to do is go for a run. Ask a runner to come to the gym with you and she/he will probably STILL go for a run that day.
And it is true, in terms of cardio exercise running is the absolute king, bar none. On a 60 minute run you will burn 3x more calories than you would on a 60 minute bike ride. The problem though is it is WAY easier to eat 500 calories than it is to burn them. And when you've got minimal muscular structure to keep your metabolism going thoughout the day you're not going to have much luck with the just running for weight loss thing.
People don't believe me when I say that when I ran a marathon seven years ago I was 20 lbs bigger than I am today. That's because I ran like a turtle – slow and steady – but I ate like a trucker all day long and then most of the night. Everyone says during marathon training you can really eat whatever you want and I REALLY took that to heart. Using running as a weight control strategy is not effective, I've tried it and then re-tried it and it just doesn't work the way eating clean does.
When a runner can't run we immediately feel like we are bound to gain 15 lbs overnight. The truth is that's just not true. Food is the number one reason why we can't lose weight. Actually food is the # 1,2,3,4,5,6 … etc. reason. Not being able to run is probably around #80 for why you might pack on the pounds.
Think of it this way, for the average runner who weighs around 150 lbs and runs for 30 minutes you're probably only burning around 400 calories. Have a half bottle of wine or a creme egg mcflurry and you're back at ground 0… mmm cream egg mcflurry, sorry lost my train of thought there!
Over the winter I always gain a little extra cushion. This past polar vortex it was around 8 lbs and I don't get bugged but it at all. It allowed me to re-confirm that I unfortunately am not the exception, I can't eat a tub of ice cream and go for a run and expect them to cancel each other out. Bah hum bug! Exercise and weight make very little difference for me. I've worked out more than ever this past winter, I feel more fit than ever but the truth remains you still cannot out run a bad diet. But believe me I've tried!
The point here is for runners in order to maximize your fitness you must workout and cross train. It took me YEARS to learn this. Weights aren't scary your bum gets bulky from too much bread and butter not from 15 lbs dumbbells. If you're a runner and you can't run right now don't stress out about it. The stress will just make you overeat and honestly sometimes it is a good thing to give your body a break. Take the time to try something else out, maybe a Pilates or a dance class? Control your intake and use the outtake as a fun activity and not a chore.