A running coach of mine once said, "Anyone can run and feel good."
Let's make that an even more general statement shall we? Anyone can workout and feel good. It's supposed to feel good. But if you want to improve yourself, it's going to have to suck at least some of the time. It's these moments of suckiness in which our bodies really improve! We break our muscles down, but they build up stronger.
For instance, I know I am not making my biggest gains from my first 9 (assisted) pull ups that are easy-peasy. It's the last 3 I squeak out with my butt cheeks clenched that are really making me stronger.
Not every workout should suck. But if you want to improve, if you want to push yourself, it needs to suck sometimes! If you run the same route at the same pace everyday, you will not get faster. If you lift the same amount of weight for the same number of reps every lifting session, you will not get stronger.
Here are some variables you can play around with to make your workout suck a little bit more:
shorten/eliminate rest periods
I was doing a Deck of Cards workout at the gym the other day. I had just done a full body lifting session and wanted to throw some plyos in at the end. I wasn't even a quarter of the way through the deck when my legs and arms were shaking and sweat was dripping off my nose and onto the mat. 10 burpees, 15 jump squats, 5 more jump squats, 30 mountain climbers... no rest in between- augh!! It sucked, sucked, sucked. But it was fine. It was over in about 20 minutes. And now I feel stronger!
How often do you purposefully make your workout "suck" a little?