Here at Jezebel, we really want to cover fitness magazines. We buy Shape and Self, we read them... and somehow, our brains run dry. After hours of concentrated thought (translation: long plane flight), we've figured out why it's so hard to talk to you about Glamour and Vogue's sweatier sisters. It's because they're actually worse than fashion mags. Sure, they claim to focus less on looking hot and spending money and more on feeling good, but in reality they make us feel bad — not just about ourselves, but about the very concept of human life. Three reasons fitness mags fill us with existential despair, using December Shape as our exemplar, after the jump.1. They're boring. You know that friend who goes on a diet and then talks about nothing else? Fitness mags are like that friend, except the diet (and exercise plan) lasts forever. At least Glamour has stories about bipolar boyfriends and kept women in foreign countries to break up all the expensive shit. But in this month's Shape, even the sex feature is all about exercising and eating leafy greens. Hot. 2. They treat food like an enemy. Sure, fashion magazines have diet tips, but these are mere skirmishes compared to fitness magazines' nuclear war. Shape's editor says in this month's letter that the holidays are a time to enjoy food. But a few pages later, Shape calls this time of year a "diet danger zone" and baked potatoes a "fat and calorie minefield." Cheesecake is not a guy with a grenade hiding in your fridge. It's just a food. Eat it — or don't. But don't take Shape's bizarre and difficult advice and measure out your portion with a shot glass. 3. They remind you of your mortality. Look, times are hard. Everyone is worried. The last thing we want is to remember that our health is extremely tenuous and the most innocent-seeming habits might kill us. Unfortunately, fitness magazines have to put out an issue every month, so they need a constant supply of newer, weirder health scares. Shape's latest: petting your dog. It won't give you a cold, but it could give you E. coli. So play it safe and wrap your entire body in plastic. Cut two holes. One is for shoving in leafy greens. The other is for sex, but only because it's good for you.