When you are trying to lose weight the idea of “oh I’m training today so I’ll have more calories but tomorrow I’m not gonna train so I’ll eat fewer calories” seems plausible. Mathematically, there is some logic to it — you don’t need those calories because you don’t burn them off so why the fuck would you eat them?
I’m taking issue with this idea because it is unnecessary. Here’s my reasoning:
First, how many calories do you actually burn in a 90-minute resistance training workout? Based on the METs or metabolic equivalents — not a whole lot (if you haven’t heard of METs, google it). If you are a female weighing 160 pounds, you would burn around 300 calories in a 90-minute INTENSE resistance training workout. Like I said, not a whole lot.
Now, if you hadn’t gone to the gym and for that same 90 minutes you chilled on a couch looking for interesting ways to kill brain cells scrolling the Instagram feed, you would have burned around 80 calories. Or if you were doing some everyday activity, like cooking or grocery shopping, you would have burned 140–200 calories.
So please try not to throw your protein shake at the screen as you read this but on a training day you are burning like 100–200 calories (200 if you are some sort of a buff animal) more than on a non-training day.
Thus, eating fewer calories on non-training versus training days is unnecessary. But hold on, there is more.
When you complete a weight lifting workout you set in motion a cascade of biological events that I won’t bother listing because I am just not that intelligent. But what I do know is that adaptation from resistance training when it comes to muscle and strength gains is a continual process — you don’t build muscle and strength in one day.
So it is very likely that by eating fewer calories on non-training days you are robbing your body of using those calories to recover from yesterday’s workout. So it can interfere with muscle growth when massing or muscle preservation when cutting.
