Zone 2 HR Training Benefits

Hi everyone!

Hope all is well on your side. Been a while - about 3-months since the last blog update. Today's update will be me re-sharing or refreshing my Lactate Threshold/Heart Rate Zone write up in January 2013 and 2019. This was greatly influenced by my personal in-activities after Ironman Langkawi 2019, and myself taking a big step in "resting" where I saw my personal fitness dropped rather significantly and decided that this is a great opportunity to rebuild my base.

I've been training this year (2020) for (to date) 38 runs and 8 cycling on my "Base-load Zone 2" (80% of the time) and pushed past Zone 3 20% of the time. This is critical if you are training as a beginner, and even seasoned age-grouper may find this useful.

As reference, the three articles i wrote on heart rate training are:
1. Finding your Lactate Threshold - 2013
2. Training Zone based on Lactate Threshold - 2013
3. Training Zone using your Heart Rate - 2019

A chart i did in 2004, way before GPS and HRM being affordable, and using stop watches and fingers as HRM was the norm. Nowadays, you don't need to do this anymore as devices are more affordable and technologically accurate

For today's sharing, I want to make things a bit simple. So this is the TL:DR version of both the write up above:
A. Finding Your Lactate Threshold 2013 write up
Look at your latest best 5km or 10km run results:

• Look for your average HR - this will be your your Lactate Threshold Heart Rate (LTHR)
• Look for your average Pace - this will be your Lactate Threshold Pace (LTpace)
• The LTpace is particularly useful if you are looking for a tempo pace. Tempo (or max Zone 3) workout should be your mainstay workout. I wrote extensively on this back in 2013 - Tempo Run
• Remember this for now, LTHR and LTpace will only improve once you get stronger and faster, this simply meant you will have to continue to work harder to achieve same level of workout quality as you improves.

B. Training Zone based on LT 2013 write up

• LTHR and LTpace relates very closely to your VO2Max or Volume Oxygen maximum which is the amount of oxygen your blood can carry (in mililiter) and process for your weight (in kg) in one minute. 
• A trained person can naturally carry and process more oxygen vs an untrained person - which is an indication of their fitness level. 
• Your LT is an indication of how much of the VO2max your body can effectively utilise. So having a high VO2max but a low LT simply meant the VO2max number is just a "nice to have" as you won't be able to maximally expense that potential. 
• In many cases, LT is a better indication of an athlete's capability to remove lactic acid faster than the muscle can accumulate. A (highly) trained athlete will reach their lactate threshold at 80-85% of their VO2Max. For this reason, many devices calculate your predicted VO2max based on the time you spent at this 80-85% HR zone.
• Run Zones (Joe Friel Formula based on Triathlete Training Bible)
  Zone 1 (Recovery) Less than 85% of LTHR
  Zone 2 (Aerobic) 85% to 89% of LTHR
  Zone 3 (Tempo) 90% to 94% of LTHR
  Zone 4 (Sub Threshold) 95% to 99% of LTHR
  Zone 5a ( Super Threshold) 100% to 102% of LTHR
  Zone 5b (Aerobic Capacity) 103% to 106% of LTHR
  Zone 5c (Anaerobic) More than 106% of LTHR
• Based on the above... the reason for a " Zone 1 and Zone 2" run became more apparent - because it is to build your cardiovascular system and build a strong base (of fitness)

C. Training Using Heart Rate Zone 2019 write up

• Co-relation between Maximum HR (HRmax), Resting HR (HRr) and LTHR. How each reading effect your training zones, and why finding the correct one is important.
• Not everyone has the same Zone 2. You need to know your HRR, HRmax and LTHR. There is no shortcut to get these data - you have to go and run and find it (also see Section A and B above)
• Again, 80% training at "easy" (up to Zone 3), and 20% at "hard" (Zone 3 and above). In simpler term, if you run 5 times a week, 4 days should be easy, and 1 day is hard. 

My HR Zones based on my HRR, HRmax and LTHR. HRR eats into many zones of HRmax and LTHR. Using HRR is better if you are an accomplished runner

• Many conversation on the internet (such as Twitter, Facebook and Instagram) has strong (and accomplished) Malaysians runner advocating using HRR as their preferred zones. I prefer to use LTHR because as a multi-sports wannabe triathlete, i need to last longer, and be more efficient, and thus, relies greatly on my lactic acid buffering ability to not get "tired".
• If you see the chart above, you will see if I were to use HRR, I will have to run harder and enter into my Z3/Z4 at HRR Z2. If I use HRmax, it will be too easy as it will stay more at my LTHR Z1
• So before you try to follow another person's plan (or pace), know what kind of HR zones you want to use, and your zone!

Why Zone 2?

Zone 2 is often termed as a steady aerobic rate where you can sustained for a long period of time. This is why it is known as a base load training. Ability to hold a conversation, keeping a steady pace (speed), and being able to run (or bike) efficiently. I can tell you it is not an easy task to run at Zone2. Here are some benefits of Zone 2 workout:

Easy 10km at Zone 2 LTHR

• A strong Zone 2 base-load training will allow you to build strong aerobic and endurance capability. It will also increase your threshold capability. 
• Please bear in mind that Zone 2 for running and cycling may differs as running is limited by your cardio-system and cycling is limited by your muscular system. This is the reason why running VO2max and cycing VO2max differs.
• A solid aerobic capacity will help you recover faster between higher intensity effort (in same session like intervals or speed-work), which meant you can perform intervals at shorter rest in-between sets, or perform a higher volume (distance, time) at the same pace. 

Higher interval volume with shorter rest, at similar pace and at similar power profile

• Sticking to lower HR training will help increase aerobic efficiency, allowing you to increase your pace with lower heart rate.With this, you can log in longer workout without sacrificing forms and functions of the run or bike - essential for long races! 
• Zone 2 LTHR allows usage of fat as primary fuels. The faster you go, the more glycogen storage your body will use - which is a limiting factor as the glycogen is being depleted, causing you to slow down as more oxygen is required to convert fat into energy. I wrote on this in 2012 : Burn Fat as energy
• Zone 2 LTHR will utilise your Type 1 muscle - or slow twitch muscles essential for endurance athletes. Type 1 utilises fat as main fuels and it is important to keep training these muscles. Fat provide double the energy of carbohydrate, so it is more energy dense (9kcal vs 4kcal per gram) and make more sense. Zone 2 will help you manage your "bonk" and "wall" at KM32 of a marathon!

I have put my wife on Zone2 workout and the improvement has been significant in space of 5 runs (80-20 rules) where she reported to be able to run easier and in more control, and in that one hard run, she has clocked likely her best 5km timing within the last few years. 

The Zone2 base training workout is nothing new, and not created by me for this purpose of the blog write up. I've been advocating and performing these Zone 2 workout for a long time as it help me to complete my endurance run and training. It is well researched and documented. And the success of this Zone 2 HR training depends on you correctly identifying your HR zones and always remember my zone 2 is not your zone 2, which is not the other person zone 2. 

Good luck in trying and let me know how it went in the comment box below!