When you engage in aerobic exercise such as running, your body primarily uses type 1 muscle fibers. These muscles rely on aerobic metabolism (oxygen as fuel). The better your body can take in, deliver and metabolize the oxygen, the better your endurance will be.
The best indicator for aerobic fitness is VO2 Max.
What is VO2 Max:
VO2 Max is the maximum volume of oxygen your muscles (type 1/ aerobic) can consume in a minute.
How to Calculate VO2 Max:
VO2 = (milliliters of air inhaled per minute)(percentage of oxygen in the air inhaled) / (milliliters of air exhaled per minute)(percentage of oxygen in the air exhaled)
VO2 max = 15.3 x (MHR/RHR)
MHR = Maximum heart rate (beats/minute) calculated using age = 208 – (0.7 x age)
RHR = Resting heart rate (beats/minute) = number of heart beats in 20 seconds x 3 (calculate just after waking up, before getting out of bed)
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What Your VO2 Max Means for Your Aerobic Fitness:
How to Improve Your VO2 Max:
High-Intensity Interval Training (HIIT) is considered the best method for improving your VO2 Max.
During HIIT you alternate between high exertion and low exertion. During the high intensity portion you get very close to your VO2 max and sustain that level of exertion. Distance running is considered moderate intensity.
- Increased aerobic fitness, measured through VO2 max.
- Increased anaerobic fitness
- Decreased fasting insulin and increased insulin sensitivity
- Reduced abdominal and subcutaneous fat
For best results, do HIIT workouts 2-3 times per week. This can be a great way to improve your running performance without going on as many patience-testing long runs.
Sample HIIT Workout:
How to Determine Which Speeds to Use:
The speeds used will be dependent on your current fitness level.
- Do the high intensity portion at the fastest you can sustain for 1 minute (Think long sprints).
- Do the low intensity portions at whatever you need to recover in 2 minutes to repeat the high intensity portion (Probably slightly slower than your typical jogging pace).