i lied before when i said i don't do cardio. i do... for 4 minutes.
it's called a tabata. if you want to read details about it, you can
here. basically it is just a 4 minute interval:
20 seconds of activity, 10 seconds of rest, 8 times each.
most people do tabatas with sprints. you can do this really easy on a treadmill, sprinting for 20 seconds and then jumping to the sides for 10 seconds. i like to do a few of these at around 10mph, depending on how i'm feeling, at either the beginning or end of a work out. i swear it sounds easier then it is.
what i REALLY love to do with tabatas is to either add a tabata (of jumping jacks, burpees, etc) in between lifts to get my heartrate up. i never thought that i could be sore from jumping jacks, but if you do them as fast as you can with good form it's definitely possible.
i also love to do 4 or 5 different tabatas for a quick, at home workout for those days that i am in a hurry or just don't want to go to the gym. here is a basic tabata workout that can be done anywhere. it focuses on the lower body and trust me, it will get your heart rate going.
tabata 1: high knees {make sure you are using your abs to lift your legs to a horizontal level. the higher you get them the better the workout. }
tabata 2: frog jumps {if you feel like you can't finish all the rounds of frog jumps, change to squats - no resting unless it is during a 10 second rest period!}
tabata 3: butt kickers {this is probably the easiest one, but no cheating. heel to your butt every time and hopefully you feel it in your hamstrings. }
tabata 4: leg lift/toe touches {while standing, lift your left leg in front of you, keeping your leg straight. touch your right hand to your left toe, then lower. repeat on the other side. again, no cheating. keep your leg as straight as possible and try to make it to a horizontal level.}
tabata 5: squats {my number one rule of squats and lunges - don't let your knees go over your toes unless you want to ruin your knees! i usually do these squats with a kettle bell or dumbell because i always try to lift heavy for my lower body since i have such a flat booty, but feel free to do them weight free. }
and there you go, a 20 minute workout (and a really awesome picture of me doing high knees!). well, 24 minutes actually, because i recommend a 1 minute rest in between each tabata.
if it's too easy - you are a rockstar and should add on 200 walking lunges with weights and some tabata sprints. if it's too hard - cut out one of the tabatas (probably the frog jumps, those are the hardest).
everyone has a different fitness level and that is perfectly fine. if you are putting in the effort to workout, then you get an A+ in my book.
p.s. i recommend getting a tabata app on your iphone! there are a bunch of different ones and most are free.