Michigan Nordic Ski Racer - Different Ways to Determine Training Zones

How to Train
Different Ways to Determine Training Zones
October 6, 2001

Heart rate training zones are used as a guide to maximize the benefit of your training. Each zone is used for training or developing a specific physiological response. Low heart rate zones are mainly for developing aerobic energy sources and pathways; higher zones may develop the anaerobic pathways or the ability for the body to clear lactic acid.

Using Maximum Heart Rate. If you don't have a handy physiology lab, there are alternatives ways of finding those zones. The easiest is to use percentage of maximum heart rate. Unfortunately, depending on who's book you read, the percentages and the number of zones vary. For example, Brian Sharkey ("Training for Cross-Country Ski Racing") defines four zones, starting at 70% of max heart rate, but Rob Sleamaker and Ray Browning ("SERIOUS Training for Endurance Athletes") have five zones, starting at 60% of max heart rate. Let's compare the two methods:

Alternative methods of using max heart rate to estimate training zones.
	% of Maximum Heart Rate Use "220 - your age" as a rough estimate of your max heart rate.
Zone	Sharkey		Sleamaker & Browning
Zone 1	-		60-70%	Aerobic energy sources Aerobic energy pathways Capillary density Mitochondria proliferation Free fatty acid mobilization
Zone 2	70-85%	Aerobic energy sources Aerobic energy pathways Slow twitch muscle fibers	71-75%	Aerobic energy sources Aerobic energy pathways
Zone 3	85-95%	Aerobic energy pathways Recruit FOG fibers Aerobic glysolysis Oxygen transport system	76-80%	Aerobic energy pathways Recruitment of FOG fibers Aerobic glysolysis Oxygen transport system
Zone 4	95-100%	Anaerobic energy pathways FG fibers Anaerobic glycolysis	81-90%	Aerobic energy pathways Anaerobic energy pathways Recruitment of FOG fibers Anaerobic threshold (AT) Oxygen transport system Lactic acid clearance
Zone 5	100%	Anaerobic energy sources Anaerobic energy pathways Fast twitch fibers Speed	91-100%	Anaerobic energy sources Fast twitch fiber recruitment Speed & neuromuscular coordination

Although the zones and percentages vary, there are many similarities: Aerobic sources and pathways are improved at lower heart rates; anaerobic sources and pathways at higher heart rates. We'll talk about the differences in the final section of this article...

Using VO² Max. If you have results from a physiology test, you can use more precise methods to determine training zones. The training zones I've been using since June were determined from testing on a treadmill during a XC Oregon physiology lab test in June (more information about that test here). The physiologists used a combination of VO², Heart Rate, and Lactic Acid levels to determine my training zones.

Sleamaker and Browning also use a method that plots heart rate against VO² utilization to determine training zones. Essentially, they use the following method to determine training zones: From a graph that plots VO² against heart rate, find the heart rates that match up to the table below to determine training zones:

Sleamaker and Browning Method of using VO²against Hear Rate to Determine Training Zones
Zone	VO² Max
Zone 1	55-65%
Zone 2	66-75%
Zone 3	76-80%
Zone 4	81-90%
Zone 5	91-100%

Comparing Methods. Using my max heart heart and the results from my physiology test, let's compare the alternative methods:

Comparing Methods of Computing Zones Mike Muha's max heart rate = 174
	From Physiology Testing		Using Max Heart Rate
Zone	XC Oregon Lab test	Sleamaker & Browning Method	Sharkey Method	Sleamaker & Browning Method
Zone 1	-	115-129	-	104-122
Zone 2	115-138	129-140	122-148	123-131
Zone 3	139-159	140-150	148-165	132-139
Zone 4	160-164	150-162	165-174	140-157
Zone 5	165-174	162-174	174	158-174

What a mess! Zones and heart rates are all over the place! Which method is the best to use?

I have several thoughts.

First, the use of a physiology test is very personal and provides the best results.
Second, a physiology test that uses more variables to determine zones is better than one that uses fewer variables.
Third, it's generally better to err on the side of going too easy than going too hard.

Based on these two criteria, I'm using my results from the XC Oregon physiology test because it takes into account VO₂, heart rate, AND lactic acid levels. Sleamaker & Browning's method based on just VO₂ and heart rate comes fairly close and is my second choice. S&B's Zones 1 & 2 match up almost exactly with XC Oregon's Zone "2". The main difference is in Zone 4 where S&B could have me training at too low a heart level. Based on my experience, I can do intervals in the 160-164 heart rate range without getting totally trashed.

How do the different zones translate into percent of max heart rate for me?

Zone	Heart Rate Range from XC Oregon physiology test	Percent of Max Heart Rate (Max = 174 bps)	Sharkey Zones	Sleamaker & Browning Zones
Zone 1	-		-	60-70%
Zone 2	115-138	66 - 79%	70-85%	71-75%
Zone 3	139-159	80 - 91%	85-95%	76-80%
Zone 4	160-164	92 - 94%	95-100%	81-90%
Zone 5	165-174	95 - 100%	100%	91-100%

And what if I didn't have the results from a physiology test? I think I'd have followed S&B's method over Sharkey's. Sharkey's 148 beats at the high end of Zone "2" is just too hard for long slow distance - I think S&B has a more realistic range. At Zone 4, it's probably still better to train less hard (S&B) instead of doing intervals up to my max heart rate.