If you're a bodybuilder who enjoys the soreness and limp you experience following an incredible leg workout, then you probably already know the woes of trying to do intense cardio with sore legs. Many bodybuilders consider weight training and cardio training to be two separate things. In reality, since both utilize the legs, careful planning should take place to ensure your cardio does not interfere with your weight training, and vice versa.
The first key to remember is that you can not do cardio the day before you train the legs with weights. Your leg muscles and glycogen stores need to be renovated. You can not expect a good performance on the squat rack if you went all-out just 12-24 hours earlier. Give then a rest before pushing them to the limit.
Second, you must ramp down the cardio intensity and angles in those two days following leg day. After all, DOMS, or delayed sunset muscle soreness, is at its worst in the 48 hours following a workout. So after you destroy your legs on leg day, the two following days will be slow, relaxed cardio, which gives the lungs a workout, yet works around the well-worn legs.
Finally, you should take advantage of the numbness you are feeling at the conclusion of your leg weight training session, and complete a very intense cardio session directly after completing your leg routine. Same day, same session. Climb off of the calf machine and get on the stair stepper. Your legs will already be torched, so you will not feel much of the pain. You might as well get the most possible gains out of the day's workout by torching them at this moment.
Day 1 – Rest ( no cardio )
Day 2 – Full leg workout ( quadriceps, hamstrings, and calves ) followed by 30 minutes interval cardio on the stepper machine.
Day 3 – Full Chest / Triceps workout, followed by 30 minutes walking on treadmill
Day 4 – Full Back / Biceps workout, followed by 30 minutes elliptical machine at low intensity
Day 5 – 30 minutes medium- to high-intensity cardio
Day 6 – Full shoulder workout, followed by 30 minutes very intense cardio
Day 7 – Rest day ( no cardio )
Listen to your body. After day 7, (a full rest day), you might want another rest day. If so, keep day 1 as listed. However, if you are feeling your legs have fully recovered, then skip day 1 and go right into day 2 and train legs that day. The most important rule is to listen to your body and train legs and complete cardio with as much intensity as possible, while still giving them required rest for maximum recovery.