Really, isn't that what portion control and working out are all about? Modification ... modifying your body, your health, your habits ...
But that's actually NOT the kind of modification I'm talking about. I'm talking about "mods" in your workouts. 21 Day Fix actually has a gal, Kat (she's awesome ... I wouldn't have gotten through my first round without her modifications and great attitude), doing modifications for every single exercise.
It's OK to be flat-out unable to do something. You have to start somewhere! I started 21 Day Fix with 3 and 5 lbs weights and now I used 15 and 20 lb dumbbells! That doesn't happen overnight, and it doesn't happen the first time you workout.
In the past I've been guilty of what could only be called something like workout bulimia. I either did nothing, or I pushed myself to the limit. Long cardio sessions, running TO the gym, working out, and running home when I was in college after months of a relatively sedentary lifestyle outside of walking to classes. Krav Maga and Crossfit where I considered it a great workout if I had thrown up at some point. Where I beat myself up if someone beat me. Where I was embarrassed if I was one of the "slow ones."
This kind of mindset and body abuse isn't a long-term health plan. It's like doing 3 sets of 10 reps of sit-ups and crunches and expecting to see abs the next morning.
You have to start somewhere, and if that means going slower, using lighter weights or even no weights at all ... you are MOVING. Slow down, and learn to think of these changes as long term. I avoided 21 Day Fix (and P90X) because of their names for a long time. "Psh, nothing can fix me in 21 Days" ... yeah, that's true. But you can start new habits in 21 days.
That side-plank in the picture? It took me nearly half a year to get to where I didn't have to modify those. I was clumsy, I was weak, but I was trying. I did the modified version (with my knee on the ground) and eventually I didn't beat myself up for it anymore. And one day, I decided to try it again. And I did it. Because I had been consistent.
Autumn is right ... you can't wish for it, you have to work for it. And you have to work consistently. But it'll eventually pay off. So you modify if you need to - there is NO shame in it! And one day, maybe after many months, you'll find out that you don't need to anymore. And you may not be at goal weight, but you'll have conquered one more little thing and that kind of victory can keep that forward momentum going!