While the treadmill is a great tool to build cardio endurance and get your miles in when it’s too frigid and icy, it can be – let’s face it – mind-numbingly boring. Music or podcasts – or if you’re lucky enough to have full TV access – are definitely helpful, especially when doing steady state cardio – but if you want to make time on Mr. T fly, intervals are your best friend.
With interval training you manipulate 4 variables: Work interval time/distance, intensity, recovery interval time/distance, and number of repetitions. Two main categories of interval training are Aerobic and Anaerobic Capacity intervals. Aerobic intervals are a great way to improve the ability of your heart to pump oxygen and blood to your working muscles. Their work intervals are 3-5 minutes with a recovery interval ration of 1:1 or shorter, stressing your aerobic system by not allowing a complete recovery. Anaerobic Capacity is the ability of your body to generate energy through the anaerobic system – or – glycolysis, therefore Anaerobic Capacity intervals increase the amount of energy and ability of your body to produce that energy using the anaerobic system. These work intervals last 30 seconds to 2 minute with a recovery interval ration of 1:2 to 1:4.
If you have a heart rate monitor you want to hit 95%-100% of your max heart rate during aerobic intervals and 90% (1-2 min intervals) to 95% (30 second intervals) during anaerobic capacity work intervals. You may find it easier to go by RPE (Rate of Perceived Exertion) instead of finding your heart rate (many machines can be drastically off). In this case your aerobic intervals would be a 9-10 and anaerobic capacity intervals would be 8-9. Use this chart to get familiar with what each intensity feels like to you. To some, a 6 min/mile sprint is their most intense interval but for others it may be a 14 min/mile power walk. Wherever you are, these intervals will improve both your aerobic and anaerobic systems.
Interval training is intense, and it’s advised to have a solid base of aerobic fitness before beginning, meaning you should be able to do 20-30 minutes of continuous aerobic activity 5 times a week. Below are a few treadmill workouts to get you started, but getting creative with intervals is near limitless! Warm up for 5-10 minutes before beginning the interval portion and cool down for 5 minutes.
Aerobic Interval Workouts
- 8 X 3 minutes @ RPE 9, 3 minute recovery
- 5 X 5 minutes @ RPE 9, 5 minute recovery
- 6 X .25 miles @RPE 10, .25 mile recovery
- 5-minutes @RPE 6, 5-minutes @RPE 7, 5-minutes @RPE 8, 5-minutes @RPE 9 X 3 (20 minute building interval blocks)
- Consistent moderate pace; 6 X .25 mile hill repeats @ 8% incline, .25 mile recovery at 1% incline
Anaerobic Interval Workouts
- 12 X 45 seconds @ RPE 8, 1.5 minute recovery
- 16 X 30 seconds @ RPE 9, 1 minute recovery
- 10 X .10 miles @ RPE 8, .10 miles @ RPE 9, .3 mile recovery
Mix in both with this ladder interval workout!
- 1 minute intervals @ RPE 10, 2 minute intervals @ RPE 9, 3 minute intervals @ RPE 8,
Work interval time = recovery interval time