The first form of circuit training was a short, intensive strength training workout that consisted of no more than 12 resistance exercises performed for just under a minute each, with minimal rest between. Resistance training in a circuit gets your heart rate up, so you can maximize your time and achieve a strength workout and a cardio workout in one session. Circuit training has evolved to include cardio exercises. You can incorporate the treadmill into different types of circuits for a variety of workouts.
Upper and Lower
One way to use the treadmill in circuit training is to make it your lower-body workout, alternating between upper-body exercise sets with free weights and the treadmill. Pre-select 12 upper-body exercises, such as overhead press, triceps extensions and upright rows. If you use different weights for different exercises, have them all at hand. Start with a three-minute warmup on the treadmill. Hop off and perform your first upper-body exercise for one minute. Don't rest. Run for two minutes on the treadmill. Hop off and go straight to your next upper-body exercise. Perform the circuit once. Add a three-minute cool down for a total workout of 42 minutes.
Full Cardio Circuit
Even though the original circuit training workout only involved resistance exercises, you can create a full-on cardio circuit and derive a similar benefit, especially if you include the stair climber and the seated rowing machine. Warm up for three minutes on the treadmill. Without resting between machines, row as fast as you can with good form for two minutes, and then climb the stairs as fast as you can for two minutes without holding on to the handrails. Run on the treadmill for two minutes, or power walk if you need some recovery. The main idea is to keep your heart rate elevated for the duration of your workout. Perform the circuit six to seven times before cooling down.
Body Weight Circuit
Performing body weight exercises in between each interval on the treadmill is a way to circuit train if you own a treadmill but don't own other equipment. You can do full-body exercises, such as mountain climbers or planks, or you can focus on your upper body and do push-ups, pull-ups and triceps dips. To incorporate some lower-body exercises, do squats, lunges and lateral shuffles. Perform each exercise with perfect or near-perfect form. After a three-minute treadmill warmup, perform a body weight exercise for one minute. If it's a plank, hold it for the duration of the interval. If it's a squat, move quickly and precisely. Rest for 15 to 20 seconds, and then run on the treadmill for a minute. Go through the circuit for up to 45 minutes.
For an especially challenging treadmill circuit routine, alternate between walking up an incline and performing one well-chosen exercise. Begin with a three-minute warmup, walking at a moderately-intense pace without an incline. Stay on the treadmill, adding as much incline as you can while maintaining your pace and not holding onto the machine. Keep the incline for two minutes. Jump to a compound exercise, such as a squat or a push-up, rather than an exercise that isolates one muscle, such as a bicep curl. Try holding a plank for one minute between each treadmill interval, for example. You can progress planks by lifting a foot off the ground or using a stability ball. Rest minimally between sets. Go through the circuit for 20 to 30 minutes.