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The Value of Running at the Top End of Zone 2

I was thinking about this topic while running in the peak of the Alabama heat this week.

I couldn't keep my heart rate any lower than the top end of my zone 2 heart rate whether I slowed down or not.

This was mostly due to the demands that the heat and humidity bring into play during the summer months.

With an accurate heart rate band, I mainly focus on trying to keep my HR right around the top end of zone 2 one easy days.

While I wanted the run to feel easier, I also know that running with my heart rate at the top end of zone also has its own special set of benefits.

Here are the benefits, even in the heat:

1. Your cardiovascular system doesn't know pace, it knows stress.

2. This HR zone allows for the maximum aerobic adaptations without accumulating fatigue on the legs

3. You still get increased mitochondrial density and fat oxidation.

4. You get better at cooling and are increasing blood plasma volume due to the heat stress

Here are the benefits once heat becomes less of a factor:

1. Ability to hold the same zone 2 HR while running 20-60 seconds per mile faster

2. Improved running economy at race pace speeds

3. More marathon-specific muscular endurance

4. Mechanical loading of the tendons and connective tissue to create a stronger and more resilient chassis.

Once cooler weather arrives, you are still training the aerobic engine, but you are also teaching your body how to move efficiently at a faster pace.

Summer teaches your heart to work efficiently; fall lets your legs cash in those gains.

P.S. - Don't be scared to ride the line of your top end zone 2.

P.S. - Your watch's predetermined HR zones are wrong and if you want them to be more accurate we can test them for you with our VO2max test.

Happy running,

R2S Team

Dr. Dylan Glass, PT, DPT, SMTC

Dr. Josh Cornett PT, DPT, COMT, CDNT

Return 2 Sport PT

www.Return2SportPT.com

256-513-9525

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