Is Your Workout Improving Your VO2 Max?
You do cardio three times a week. You work up a sweat. You feel like you are training hard.
Your VO2 max has not changed in two years.
In case you don't know, VO2Max is the maximum rate your body can use oxygen during exercise. It is the single best predictor of cardiovascular mortality.
A 3.5 ml/kg/min increase in VO2 max reduces all-cause mortality by 13%.
Most people training for "cardio health" are working at an intensity that maintains their current VO2 max but does not improve it.
Here is the training threshold. To increase VO2 max, you must work at 90-95% of max heart rate for at least 4-minute intervals.
This is not comfortable. You cannot hold a conversation. Your breathing is labored.
The most effective protocol is Norwegian 4x4: four minutes at 90-95% max heart rate, three minutes active recovery, repeated four times.
Twice weekly improves VO2 max significantly in 8-12 weeks.
Compare this to typical "cardio." Most people jog at 60-70% max heart rate for 30-40 minutes. This is zone 2 training, valuable for metabolic health and mitochondrial density, but it does not push your cardiovascular ceiling higher.
Training exclusively in the moderate intensity zone is not ideal.
The 80/20 rule helps. Eighty percent of your cardio should be easy, conversational pace, building aerobic base.
Twenty percent should be legitimately hard intervals, pushing VO2 max upward.
You need to test VO2 max to know if you are improving. Lab testing is gold standard, but expensive.
Wearables estimate it reasonably well if you do a max effort test regularly. Track it quarterly.
Your VO2 max declines about 10% per decade after age 30 without intervention. High-intensity intervals can slow this to 3-5% per decade.
Get a baseline VO2 max test, either in a lab or via a wearable max effort protocol. Replace one weekly cardio session with 4x4 intervals at 90-95% max heart rate.
Retest VO2 max every 8-12 weeks to confirm your training intensity is effective.
The ability to ingest and deliver oxygen determines to a great extent, the quality of your life.
Ritesh Bawri
Founder, Nira Balance. Harvard Medical School (Physiology) & Tufts Medical School (Nutrition). Helping people reverse lifestyle diseases through first-principles health science.
