Heart Rate Zones

Key points in this session

  • How to identify your heart rate peak
  • How to identify the two key training thresholds
  • How to set up your heart rate zones for a polarised training approach

Targeting your training with zones

It’s possible to target one or two of your body’s energy systems, such as your anaerobic power or aerobic endurance systems through focussed training at an intensity that stimulates the targeted energy system. As a rule of thumb, training in each zone stresses one or two energy systems while minimally impacting others.

Tip: Training harder all the time is not always better. If you only do intervals on the ergo or in crew sessions, you may build great anaerobic and lactate threshold systems, but your aerobic endurance will suffer and you can run the risk of building up excess fatigue.

All effective training zone models centre on two key metabolic events, that occur as we increase our training intensity. The two events are commonly called thresholds.

  • Aerobic threshold, the lower and first threshold (LT1) is the point where blood lactate levels begin to rise above 2 mmol/L. It is the point at which we begin to recruit fast-twitch muscle fibres.
  • Anaerobic lactate threshold, the higher and second threshold (LT2) represents the highest power or heart rate that can be sustained aerobically. It is the point where blood lactate levels begin to rise above 4 mmol/L.

Heart rate zones

It is important to pay attention to your Heart Rate during training, to monitor and manage the intensity of your training sessions. This way you can manage your intensity, when you are supposed to be in a particular zone, especially when you are rowing alongside, or with your crew mates. Discipline in training to your target intensity is key.

Many physiologists use 3 zones, delineated by the two metabolic thresholds mentioned earlier. In reality, our physiological zones overlap, so for training purposes, we will be using a 5 zone model.

Here are the 5 zones that we will be using in the Masters Training Plan.

Zone 1: Below aerobic threshold. Targeting aerobic endurance and used for recovery sessions.

Zone 2: Below aerobic threshold. Targeting aerobic endurance and fatigue resistance.

Zone 3: The range between the thresholds. Targeting lactate clearance and transition to higher intensity training.

Zone 4: Lactate threshold. Targeting maximal sustainable power.

Zone 5: VO2max, anaerobic capacity, and anaerobic strength. Targeting anaerobic pathways and maximal effort capacity.

Example using heart rate peak of 185 beats per minute.

Data provided with athletes permission. Age 49, 194 cm, 80 kgs, heart rate peak 185. (2020)

Identifying your heart rate peak

First things first, you need to know what your actual heart rate peak is. It is not just 220 minus your age! This formula works reasonably well at the population level but it's unreliable at the individual level.  Dr Seiler, recently published the results from a study, comparing age vs. heart rate peak of 157 well trained cyclists (see chart below). What they discovered was enormous variation of maximum heart rate by age. Don't risk over training. To accurately target your training, and to train smart, you need to identify your heart rate peak.

Data courtesy of Dr Stephen Seiler PhD (2020)

Typically rowing will give a higher heart rate peak than other sports and the way you can identify this heart rate peak, is through a hard 6-minute test on the ergo.

The 6-minute test is very very hard. You must be well warmed up and both mentally and physically ready to race. From the start to the finish, you need to row as hard and as fast as you can over the duration. It means high rate and high watts. You need to complete the test knowing that you have given everything, and have nothing left to give. 

Now that you have identified your heart rate peak, this number sets the top end of zone 5 at 100% max.

Tip: If you are using Garmin device, you can run a heart rate max report on your the last 3-months activities from the Garmin Connect website.

Estimating the first lactate or aerobic threshold (LT1)

Now that you have identified your heart rate maximum, this number sets the top end of zone 5, your heart rate at 100% peak.

If you want to find the first lactate turn point, you ideally need to measure lactate at 2 mmol/L, and identify your heart rate and power/pace at this point. However, as this course is to arm you with pragmatic solutions and actions you can use now, a reasonable educated estimate of 75% heart rate peak for the top of zone 2. 

If you really are in zone 2, you should not see a big drift (upward movement) in your heart rate during the session. The heart rate you have after 15-minutes should be the same as at 60 minutes. If your heart rate is drifting up, there's a good chance you're working at a higher intensity than you think you are or you are getting dehydrated.

Tip: When training in zone 2, Slower can make you faster. check the ego at the door! Women tend to be better at discipline, but men generally find it harder. However, learning discipline will be one of the best things you do. 

Note from a World Champ: Training in zone 2 is harder than you think. It's hard because it's tempting to go harder, and start competing with your best times. Don't do this. Watch your heart rate and not the pace or power on the ergo. Focus on the purpose of the session, which is to build the motor and burn fat for fuel. Also don't underestimate how fast you will be going when you are Aerobically efficient.

Estimating the second lactate or anaerobic threshold (LT2)

Now you have your maximum heart rate and your Aerobic threshold (zone 2) all sorted, now you need to determine your anaerobic threshold. To determine this threshold point, I generally recommend doing an hour of power on the ergo or in the single. When you do the 60-minute test, take your average pace/power and heart rate for those 60 minutes. You can use both of these numbers as your zone 4 threshold for heart rate and pace. This is the marker between zone 4 and 5 and generally is around 94% of your heart rate peak and producing 4 mmol/L of lactate.

Research shows that well-trained subjects can generally hold maximum lactate steady state for an hour, so it's a reasonable surrogate measure for your anaerobic or lactate threshold.

When you do an hour of power, your average heart rate for that hour will probably be around 90% of max. By the end you may be at 95% of heart rate peak, but that's heart rate drift. The moment of truth comes around two thirds in - you know your body will start wanting to quit here so you need a mental strategy for how you can get past this. Make sure you're well hydrated and have a fan running if you are on the ergo.

Tip: With the right training you will see the what you can sustain at your anaerobic threshold improve. It's not always about doing more power, it's about being able to do the same power for longer, and feel comfortable with this. This means you have a bigger aerobic base. The only way to get this is to do the hours over time. There are no shortcuts. 

Setting Your Heart Rate Zones

In theory setting up your heart rate is essentially the same for all sports because physiology is physiology! 

In the graphic below, you will see the 5 zones laid out with the two thresholds used in the Polarised Training model clearly identified. These zones reflect the Polarised Model in the literature and have been validated by Dr Seiler.

You can use the Zone percentages to set up your Garmin or other heart rate monitor.

Now that you have your heart rate training zones clearly identified and programmed into your heart rate watch, you’ll be able to monitor your training intensity and following the training prescriptions to make you faster