As a trainer of busy moms I like to help women find that they do not need as much time as they think to get their workout in... the suggestions below could be an addition to your Moms on the Run training program or as a substitute workout during off days.
Here's what you can do on the morning, in only 15 minutes! (why in the morning? because you only have time to shower once:) )
Step One: Take the clothes off the treadmill the night before.
Step Two: Warmup for 4 minutes walking, gradually increasing your pace.
Step Three: Do one minute very hard (running or fast walking) followed by one minute easy (walking or an easy jog), repeat 4 times.
Step Four: Do a 3 minute additional cool down.
That's it! You will burn more fat all day long due to the effects of intense interval traning on your metabolic rate. Long boring cardio sessions not needed. This does not get you out of strength training. Ha.