Zone 2 Versus Zone 5 Training

You may have heard about the importance of Zone 2 and Zone 5 training for health and fitness. But what are these new buzz words? And how much do we really need? Read on!

Zone 2 training is just a new term for what have been doing for years…aerobic steady state exercise…traditionally walking, jogging, swim, and stair climbing done at a relatively easy pace. During zone 2 aerobic training, you can breath in & out through your nose. Nasal breathing is important here as “aerobic” means in the presence of oxygen…therefore oxygen is required for energy production during Zone 2. Think of Zone 2 training as the base or foundation of all zone training. Again, remember the nasal breathing for oxygen as I’m going to go deeper on that after
this…

Zone 5 training, on the flip side, is high intensity or anaerobic threshold training. For years we have known it as HIIT training. Now, we call it Zone 5. “Anaerobic” here means “without” oxygen. Remember when you were sucking wind in your last sprint? That’s your body going anaerobic to fuel your muscles

As long as your cardiovascular system delivers enough oxygen to working muscles, the aerobic energy system can keep up with muscle demand for fuel. This fuel source (fat/carbs) can go on for hours. This is why we can walk for hours!

Once breathing intensifies and you find yourself inhaling through your mouth, the aerobic energy system can no longer keep up with the demands of the working muscle.

The anaerobic energy system kicks in to to provide fuel (glycogen) - but that fuel source is limited to a few minutes. Once you find yourself needing to open your mouth to breath, your energy system is leaning away from aerobic and moving towards anaerobic.

By practicing nasal inhalation as long as possible (*note exhaling out your mouth is ok)
during a walk, jog, run, stair climb, spin…you will train your body to stay aerobic (and use more fat for fuel) under increasing exercise stress.

Back in the 80’s & 90’s we used aerobic training to burn calories for weight loss. We know now that is a poor use of exercise time (a blog post for another time). Nonetheless, there are still benefits to Zone 2 work including:

• Increased cardiovascular health (bullet proof heart and lungs)
• Increased blood oxygen transport & circulation
• Increased blood vessel density and mitochondria (power house of every cell) in our muscles
• Increased ability to burn fat as fuel (the flip side, this isn’t license to eat whatever you want)

For me…the most important benefits of Zone 2 training are regarding the brain. Many scientist agree that exercise is the number 1 preventative measure for neurological decline…even greater than any pharmaceutical drug out there.

• Just like muscles, your brain benefits from zone 2 training with improved blood supply
  health and mitochondria in the brain!
  • Zone 2 training triggers the same brain centers as meditation
  • This helps you tap into your parasympathetic nervous system or “rest & digest”
  • Improves mental health including stress, emotional resilience, mood, creativity, focus,
    immunity and sleep

Let’s not forget the Zone 5 benefits!

• Increased power and speed (Don’t think you need this? What about the next time you have to dodge a car out of nowhere on your Zone 2 walk?)
• Increased lactic acid tolerance in muscle
• Improved muscle economy and efficiency
• Most importantly, USE IT OR LOSE IT. Train Zone 5 to hold onto your “fast twitch” muscle fiber. I failed to mention before, Zone 2 uses “slow twitch” muscle fibers which are preserved as we age. As we get older, we lose fast twitch UNLESS we work it.