no gym necessary. lunge up and down a hill for 20 minutes, then do some pilates. FWIW, i consider 30 minutes more than enough time to exercise effectively. heck, i have a 10 minute workout that often makes me shake for an entire day, but i digress.

here is my lunge mania workout that takes 20 minutes or less. it's an ass buster too.

-walking lunge front, pull up toes in the show to target glute.
sprint back
-walking lunge front, pull up heel off the ground to targe quads
sprint back
-walking lunge wide to the side, like a sumo squat.
sprint back
-walking lunge wide to the side, lead with the other leg this time
sprint back
-walking lunge backwards and pup off the front foot
sprint back

rest a couple of minutes

lay on ground, hands under lower back or more advanced lay them strait out to the sides. put legs up in the air and lower barly to the ground, do 3 or 4 sets of 10. each set try to lower slower.

to make this workout more advanced, put hands on head (like getting arrested, LOL) or hold arms straight out to the side during lunges. super advanced is to hold palms up, arms straight out, with a small ball balanced in the palm.

these are the kinds of workout i do now, it is fast, challenging and no gym required.