Like many things ‘fitness’, heart rate training is one of those methods that some people get obsessed with and others don’t see the point.
There always tends to be an over-reaction in the short-term when something is discovered and an under-reaction in the long-term.
In other words, those who are just into fitness for entertainment and something to do, tend to get excited by anything new, shiny and different.
These people rarely get anywhere because of their ‘Fitness ADD’ because they never stick with anything long enough to make their body adapt and improve.
They over-react in the short-term and think EVERYTHING needs to involve their shiny new toy or training method.
Think BOSU’s and anything wobbly.
Think kettlebells.
Think power plates.
In the long-term however, because new shiny stuff comes along, these methods get dismissed completely and the person loses out on any benefits offered.
I believe the same thing has happened to heart rate training.
I have recently embarked on a journey into Muay Thai training and am now carefully monitoring my conditioning, body composition looking to optimize:
- Power to body weight ratio
- Body composition
- Recovery potential
- Anaerobic and aerobic conditioning
The more improvements in these I see, combined with improving technical ability, the better I will perform in Muay Thai fights.
Now we could be here all day discussing the ins and outs of cardiovascular training but I want to cover the main arguments for and against using your heart rate as a training tool. Something which I made the mistake of ‘under-rating’ until studying with world-renowned fight conditioning expert, Martin Rooney.
The aim of the article is to consider the science but also take a common sense approach and point out what I think is pretty obvious but often ignored!
YOU NEED TO GET IN THE ‘FAT BURNING’ ZONE
The argument goes that at a certain percentage of your predetermined maximum heart rate you switch from utilizing fat as an energy source to burning glucose from your muscle stores which get there from the digestion of sugars in your diet.
Going above this percentage means you are no longer burning fat, therefore you should stay in a heart rate zone of somewhere between 70-80% of your maximum heart rate.
This is often referred to as the aerobic zone. Because oxygen is required in the process that breaks down and uses fat for fuel, the argument says you should stay in that ‘work rate’ zone in which your body is able to process the oxygen and keep fat burning going.
Going any harder means your body can’t get enough oxygen in and switches to the ‘anaerobic’ system (without oxygen).
Therefore, if we use heart rate training to stay in the right zone we will burn more fat.
Unfortunately it is not that simple.
First, when we train in the anaerobic zone and increase lactic acid production in our muscles, we deny the body of oxygen for periods of time (which can be very stressful!).
Between these intense bursts or ‘intervals’ our heart rate settles somewhat and is still in the ‘fat burning’ zone. However, this is largely irrelevant compared to what happens AFTER and BETWEEN sessions when the body is forced to increased the metabolic processes going on in your body in order to recover and restore your body to the state it was before complete with adaptation – the very point of ‘training’.
This is known as Excess Post-exercise Oxygen Consumption (EPOC).
It’s necessary to focus on how we can maximize your metabolic rate and fat burning BETWEEN sessions more than DURING them.
To do this, we require hard training sessions and extra lean muscle.
If working too hard didn’t help burn fat we would have to ask the question, “Why are sprinters and people engaged in interval-based sport not fat?”
These people have much better bodies in general than stick-thin, gaunt looking marathon runners who spend most of their time in the ‘fat burning’ zone.
This is not to say that I don’t believe in aerobic exercise or ‘cardio’
Everyone needs a good dose of oxygen and to work their heart and stay healthy, especially in these days of spending most of the day in buildings, but there is a lot of misunderstanding around ‘cardio’.
The whole heart rate zone thing led to the dawn of ‘jogging’.
However, as you will know if you do a circuit such as pushing or pulling a sled, carrying some heavy objects and sprinting up some stairs, you will know that there are many ways to work your heart muscle without mindlessly ambling along trying desperately to not go over 75% for fear of not burning fat.
MAXIMUM HEART RATES
The other problem with using ‘zones’ is that:
1) I have seen people who can get near their supposed maximum heart rate but stay there for much longer than others without blowing up as most do after 2-3 minutes of being around 90% of their max.
2) Conversely depending on your fitness levels, you may blow up much earlier at a lower percentage of your maximum no matter how hard you try to force yourself. This may be because your muscles are sufficiently strong or conditioned to cope with even being at 70% of your maximum heart rate.
For me, this is where zones can be a good rough guide for a beginner but the benefits and help it provides don’t really outweigh the possible inaccuracies.
That said, a very well-trained athlete who really knows their body might find it beneficial and useful for holding them back when, as most athletes do, you just want to ‘go for it’ because you feel good one day!
Too many of these sessions can leave you overtrained, so the heart rate zones may be of benefit there.
HEART RATE MONITORS ALSO HELP YOU COUNT CALORIES
Again this is a bit misleading.
It might work in a carefully controlled scientific experiment, but there are so many things affecting your metabolic rate and calorie burning that it can be more damaging than it is useful.
This includes hormone imbalances, digestive issues, energy conversion, thyroid function, stress levels.
Also, it’s based on weight and height calculations. Like BMI, how does this differentiate between the 110kg mountain of muscle with a metabolic rate through the roof, and the sluggish, hormonally challenged obese lady of the same weight?
MONITORING RECOVERY
At this point, you’re probably thinking I am actually a heart rate training opponent.
Actually I have developed a love for it as part of my Muay Thai training for measuring recovery.
When in competition with all the added stress and adrenaline, the more you can stay out of the higher heart rate zones the better, helping you avoid those moments when your body forces you to stop because it can’t handle the stress.
Being able to slow everything down faster to a level at which you function aerobically rather than anaerobically is very useful and will enable you to perform a greater number of intense bouts of activity.
Think about a boxer who has a 1 minute rest between 3 minutes of stressful fighting.
During that minute, if he can slow his heart rate down to a level at which he can process oxygen and remove carbon dioxide and lactate build up from his body, he is in a better position to step out for the next round.
This is where I have been using heart rate monitoring to measure my recovery improvements.
Twice per week I complete 3-4 rounds of a fast-paced 2.5-3 minute conditioning circuit in which my heart rate reaches 80-85% of my ‘Max HR’ with 1 minute recovery in between.
The % (as discussed above) is not what I’m interested in but consider the last three weeks times and heart rates at the end of the recovery period.
The circuit is exactly the same each week.
WEEK 1
Time to complete circuit: 3.12 – 3.29 – 3.37
Heart rate at 55 seconds rest 145 – 142 – 146
WEEK 2
Time to complete circuit: 2.48 – 2.57 – 2.54
Heart rate at 55 seconds rest 142 – 140 – 145
WEEK 3
Time to complete circuit: 2.25 – 2.33 – 2.41
Heart rate at 55 seconds rest 136 – 134 – 139
My heart rate has been consistent at the end of each round indicating that it’s not just the fact that the work time is reduced which enables my body to reach a lower heart rate within the minute.
This gives me valuable data on my recovery ability between intense rounds.
It also highlights another argument about training variables.
Most people will say you MUST increase weight or reps or reduce rest time each week in order to ensure ‘progressive overload’ and adaptation.
Whilst I agree almost completely, this gives us another variable to track even though the circuits remained exactly the same.
I believe this has particular use for people with indications of heart dysfunction.
Now we can see if a person’s heart is better able to cope with stress and recover faster.
After a tough flight of stairs for a beginner, this could be the difference between life and death as most heart attacks occur after short periods of abnormal stress.
For some people this is a sudden massive trauma but for very unfit, obese people it can be something as simple as a quick push to reach the bus in time.
For this reason I don’t believe heart rate training can be completely ignored.
WHY NOT USE RATE OF PERCEIVED EXERTION INSTEAD?
Another argument goes that you can use a scale of perceived exertion.
So if I am at 9/10 I am pretty much at my limit and about to collapse – I might be able to do another 20 seconds!!
This also has value but if I ask a beginner where they are on the scale after a hard 3 minutes they are likely to tell me 8 or 9 when in reality they just aren’t use to it and with a gun to their head they could on for another few minutes.
In this case asking a person to rate themselves is not going to help us accurately record their recovery potential and how well their heart function is improving.
Also the week before the results you see above, I was badly jet-lagged.
In training my heart rate was down at 130 at the end of the rest breaks.
However, the times were slower because I just couldn’t get going and everything felt difficult.
I felt just as tired after 50 seconds recovery (if not more so) than when my heart rate was at 145 in the subsequent weeks.
On the face of things, I was recovering better in Week 1 because my heart rate was slower.
However, in reality it was because I couldn’t force my body and heart to work any harder because I was jet-lagged!
If I had tracked my heart rate DURING the bouts as well, it would have been even clearer that there was a problem.
My rate of perceived exertion would have been 8 or 9 because I really did struggle to make myself strain but it just wouldn’t happen.
So I think rate of perceived exertion is useful in certain circumstances but when someone is stressed out, jet-lagged etc, it can again be a little misleading.
Which brings up back full circle to where we started.
Don’t dismiss anything out of hand but don’t get obsessed with it either!
So long as you keep an eye on different training variables and monitor them, you can keep track of how well you’re progressing.
Some people argue “I know when I’m working hard” but if I put them in a more competitive situation they would improve their performance.
Don’t assume you’re working as hard as you think just because there’s some sweat!
The body and mind are more complex than you think so it’s important to look at the effects of different stimuli, different stress levels and different measurements RELEVANT TO THE TRAINING OBJECTIVE.
If you are in it for muscle growth and nothing else, I wouldn’t bother measuring your heart rate.
In the same way as if you want to improve your conditioning and recovery ability, I wouldn’t bother measuring your biceps!
Keep your eye on the RIGHT ball and don’t get be too polar in your thinking about fitness training.
