Don't feel like doing traditional cardio? Feel soft when you are on an elliptical machine, like its stealing your manhood every time that you are on it? Have some fun with it and add different exercises to your training.
Switch it up, switch it up. How about adding some shadow boxing or heavy bag kicks and punches to your weight training session?
For example, let's say that you are working on squats for the day. Now you have to pick weights that are around the 70-80% range or even lower. It's simple. You perform a set of squats and then you immediately go to the heavy bag and either do punches or kicks. If you have somebody to hold Thai pads for you, its even better. And if you don't have a bag or Thai pads , then you can shadow box adding kicks and knees in there also. You don't want to do so many punches and kicks that you can't finish the next set of weights, so make it hard, but quick.
Here is a workout that I used to do all of the time-
Sets of 6 in the squat at 70%, immediately followed with 20 hard punches on the heavy bag or Thai pads, mixing up the punches. Then take a minute rest or you partner goes after you. Then go back to the squats. After the squats, immediately do 10 left kicks and 10 right kicks. After the next set of squats, do 20 total skip knees on the bag or Thai pads. And you can change it up all the time. Some sprawling can be added in there, also. Punching, kicking and knees are the best way, in my mind, to get some cardiovascular training in without boring cardio, and stay sharp self defense wise and get your lifting in at the same time. Obviously, if you are training for a powerlifting meet, this should only be done early on in your training cycle, but you can do this for football and sport training in season and offseason, except when you are close to peaking for strength.
You can also go outside for some training. Find a hill or some stadium steps and bring some weights with you or maybe a heavy kettlebell. Run the hill or stadium and then immediately when you get back to the bottom (or when you get to the top), do 10 kettlebell swings, or presses or even get-ups. Be creative with it.