I started dabbling in running after college to help me lose the 40 pounds I had gained [1]. For years after that, running was part of my life on and off [2], but I didn't seriously get into it until after baby number two was 2 and a half years old, and I was ready to ditch the baby weight I was still holding onto.
How Much Did I Run?
It was March 2016, and the weather was just starting to get nicer, which inspired me to commit to running more regularly, three times a week (three to four miles). After about a month, I kicked it up a notch and started running four times a week. On Mondays, Wednesdays, and Thursdays, I ran from 6 to 7 a.m. (six miles) with some mommy friends, then I did solo 80- to 120-minute runs on Saturdays. I kept up these four weekly runs for about three months, through the end of June.
What Happened?
After three months of running four days a week, at least an hour each time (getting in about 24 to 26 miles a week), I was excited to step on the scale, convinced all my hard work would show.
I thought something was wrong with the scale.
I thought something was wrong with the scale. I seriously thought something must be wrong because I had gained almost 10 pounds [3] in the four months since I'd started running. Nope, it most certainly wasn't muscle, because when I compared photos of myself from April, my face and belly looked pudgier.
My first thought was that I needed to run more often, run longer, run faster, or do more hills. Then I came back down to earth and realised the issue wasn't how much exercise I was getting — I was doing more than enough! — I needed to point the finger at my diet.
My long morning runs caused insane hunger, and I was noshing all day long. A snack after my morning run, breakfast, another snack, lunch, a snack, dinner, than another little something before bed — I was eating a crap ton [5], but I thought that hour-long run gave me the green light to. I was actually burning way fewer calories than I thought I was [6], and eating in a calorie surplus is what caused the scale numbers to go up.
What I Did to Fix It
When I realised I was eating with reckless abandon, I took a closer look at my diet and cut out both the postrun and prebed snacks, so I was only eating three meals and two snacks in between. I focussed on getting more protein and including healthy fats and more fibre at each meal. I also cut down on the processed carbs and sugar [7] I was eating every day, and that definitely helped.
Aside from eating more than I needed, another reason I was gaining weight was because I was only focussed on doing steady-paced cardio. So in July, I gave my runs a rest and started doing CrossFit [8]. Now, almost two years later, I still do some running here and there, but adding weight training and high-intensity interval training (HIIT) made a huge difference in my body composition.
I also incorporated intermittent fasting [9] eight months after starting CrossFit, and that was the key to boosting my energy and helping me get a handle on sugar cravings and my tendency to eat all day long, which ultimately helped me lose the belly fat [10] that running had actually increased.
Can Running Cause Weight Gain?
Absolutely! For me, running a lot, eating a ton, and not varying my workouts definitely caused me to gain weight [11]. This was a huge surprise to me, since I originally started running to slim down! So if this sounds familiar, you're not alone. It is possible to run for weight loss [12]. Just be sure you're running enough, mixing up your runs with some HIIT [13] and weightlifting, and eating in a calorie deficit.