Exercise Tracking

MFP isn't the greatest for tracking exercise, but you can add exercises by specifying the minutes and calories.

I suspect you've been trying to use the Strength Training section on the Exercise tab. That section is specifically for when you do want to enter sets, reps and weight. Instead, select Add Exercise under the Cardiovascular section. Search for "strength", then you'll be able to select Strength training (weight lifting, weight training), and enter the duration, start time and calories burned. This works for just about any type of exercise, whether you think of it as cardio or not.

That said, there is also the option to copy exercises from one day to another. You needn't enter them from scratch each day. So, if you had a workout plan where, let's say, you alternate upper body workouts and lower body workouts, with a set of exercises for each, then once you've entered them for one day, you can copy them to future days. You could actually have any number of planned routines to select from, if you kept track of the day you first entered each routine. Once copied, you could add/delete as needed for that current day.

Of course, none of that is necessary if you can afford a fitness tracker. Also, I imagine there are at least a few phone apps that can time your routines, estimate your calorie burn, and sync that data automatically with MFP, without the need for something like a fitbit, apple watch, Garmin, etc.