Training based on low heart rate can be frustrating. We’ve all been there, where lowering the heart rate means reducing your runs to countless walk breaks, and even the easiest of runs takes the heart rate number up way deep into those grey and red zones. If nothing else, trying to control the heart rate is known to crash all the so-called joys of running (or training, if you may) and make it a painstakingly boring process. And for all the merits of taming the heart rate, it’s an excruciatingly slow journey, one that makes us want to give up and jump into some ‘rebound speedwork’ sessions.
So how do we do it? In this article, we present tips on how to smartly strategise low heart rate training and ease the stress around the holy grail of endurance running.
Why Low Heart Rate Training
Let’s start by understanding the science behind low heart rate training. A high power output at a low heart rate is the de-facto holy grail of endurance sports. Sustaining a high-enough power output at a low-enough heart rate puts less stress on the cardiovascular system while presenting adequate energy to the muscles to fire and makes ultrarunners go on for long durations of time. In other words, training the body to produce high power while functioning at a low heart rate is the key to race winning ultrarunning performances.
A lower heart rate (during activity), in itself, is the result of two types of cardiovascular adaptations:
Enhanced high pumping capacity - this refers to the heart's ability to pump more blood per beat (stroke volume), which is a key adaptation from endurance training;
Fatigue resistance - this refers to the heart's ability to sustain prolonged activity without fatigue is a result of increased cardiovascular efficiency and mitochondrial density in muscle cells.
To achieve the desired results of lowered heart rate during high-powered performances, it is, therefore, important to train the body to both these adaptations. Overemphasis on one, however, can result in diminished returns from the other, or run the risk of injuries. Yet on the other hand, ignoring any one will leave unrealised gains on the table and prolong the process unnecessarily. Understanding these concepts forms the basis of smart low heart rate training methods.
Strategising for Low Heart Rate Training
In the following sections, we highlight the basic steps one can take to make low heart rate training less stressful and overwhelming. These may not guarantee results, but will guarantee success via a sound process and a focused mind.
1. Make Room for Variables Outside Your Control
The first step to managing low heart rate training is accepting that it’s not easy. If it were, everyone would be running their personal bests at the mid-end of there zone 1. Lowering the heart rate requires extreme patience and resilience to what could otherwise be a frustrating journey.
Heart rate, in itself, is affected by a number of variables. Heat, humidity, sleep quality, sleep duration, stress, time of day, hormones, menstrual cycles - everything impacts the heart rate. Since none of these variables are under our control, the best step forward is to start planning around them. For example, on a humid day, going slower than usual and hydrating more frequently can help keep the heart rate under control. Similarly, proper meal timings and intake can ensure a better night’s sleep, which can help control the heart rate the next morning during the run.
Hormones, on the other hand, are a little more complicated. Hormonal releases are complex processes that are a result of physiological, psychological and other metabolic systems at play, which makes it harder to control from a low heart rate training perspective. While activities can be planned around hormonal cycles and imbalances (e.g., stacking harder workouts during the follicular phase of the menstrual cycle), it is still not a guarantee that the larger goal of lowering the heart rate will be achieved.
In effect, the best starting point to not getting overwhelmed with low heart rate training is accepting that there are variables that will always come in the way of the goals and that it’s okay. With better planning of activities, the barriers can be reduced, if not eliminated altogether.
2. Ditch the Noise from the Signals
That piece of technology on our wrists is powerful. It just sits there but knows everything about us - or at least claims to know everything about us. The quantification of what’s happening in our bodies comes from watches, rings, arm bands, chest straps, continuous glucose monitors and so much more. In terms of numbers, these devices paint detailed pictures of where our bodies are with respect to health, lifestyle and performance metrics. In today’s world, it’s ever so easy to get lost in the sea of data-driven profiles that have been created about what’s happening inside us.
While modern technology offers powerful tools for monitoring our health and performance, consumer-grade tech suffers from two main problems:
They don’t measure everything they present directly; and;
What they do measure directly are not always accurate.
To illustrate this, picture a wrist-based ‘maximum’ heart rate measurement of 180bpm. Wrist-based heart rate monitors can be inaccurate by more than 10%, which means the 180bpm is likely to be off by +/- 18bpm in either direction. But the software, which will treat the number as the ultimate truth, will end up calculating training heart rate zones based on this 180bpm number. When a coach or an athlete now uses this data to plan the next workout, they’re essentially triggering a cascading effect of wrong measurements - or in simpler terms, their ‘prescribed’ zone 2 run might actually end up being in their biological, actual cardiovascular zone 3.
Measurements around sleep, VO2max, lactate threshold, HRV status are all estimated based on certain measurements, the accuracies of which are themselves questionable. This is where it becomes important to separate the noise from the signals, and instead, keeping an eye on how data is trending rather than fixating on the actual numbers.
For example, in a post-race 2-week detraining period, the HRV will decrease and go into the unbalanced ‘downward’ zone. On the other hand, during the peak phases when training volume and intensity increase, the HRV will increase and go into the unbalanced ‘upward’ zone. In a similar vein, not applying progressive overload to running will cause a plateau to the lactate threshold - while heat, humidity, lack of sleep etc. might measure new levels of lactate threshold without having applied the actual cardiovascular stimulus.
The most effective way to separate the signal from the noise is to look at how data has trended, and to identify, understand and document the reasons for that trend. And in case of low heart rate training, being data-driven need not be any more complicated than asking ourselves, “what is the data that shows that today’s workout felt easier than the last time I attempted the same workout?”
3. Don’t Try to Make All Easy Runs Low Heart Rate Runs
There is much advice online about weekly intensity distribution in running. While the said distribution can be debated in favour of individualisation, the problem here is the conflation of ‘easy’ with low heart rate. Add to this, the complexity of bringing ‘slow’ into the mix. The outcome is the expectation that running slow will result in low heart rate, which will make it easy.
And this is where it can get frustrating.
The desire or requirement to achieve a low heart rate ends up slowing us down, as the brain starts equating easy, slow and low heart rate. As a result, it turns into an endless process with no fruits or rewards within reach.
To decouple the three means having an understanding of what each signifies.
Easy is a measure of effort, i.e., the input;
Slow is a measure of movement speed or pace, i.e., the output;
Low heart rate is a measure of improved aerobic capacity, i.e., that black box between input and output.
So instead of trying to see all easy runs as low heart rate runs, a better strategy is to measure the significance of these three aspects in isolation. If easy is the goal, then it should feel easy, no matter what the pace or heart rate are. If a certain pace is the goal, then the run should be in that pace or speed zone, no matter the effort or heart rate. And if low heart rate is the goal, then the heart rate should be at a low heart rate, even if it felt hard and fast.
By compartmentalising the desired output, the mental overload of trying to achieve three objectives can be eased by instead going after a single objective.
4. Treat Low Heart Rate Training Runs as Targeted Workouts
This is merely an extension or a rephrasing of point 3 above. Focusing on one objective at a time also means that time needs to be distributed across the three objectives. While this can mean fewer opportunities to focus on one aspect, it also means more opportunity to focus on achieving a single objective.
Treating low heart rate training runs as specific, targeted workouts is one way to reduce the overwhelming feelings of frustration. In other words, a typical week with 5 runs can have just 2 ‘easy’ runs where a low heart rate is targeted. Even for ultrarunning training, easy runs (as opposed to long runs) need not exceed 45-60 minutes per workout, with ~75% of time spent in the low heart rate zone.
Following this approach also helps break monotony by mixing things up in terms high and low heart rate, pace and effort. This can automatically create a cognitive paradigm where, in an apples-to-apples fashion, relative progress patterns will start forming between ‘similar’ runs over consecutive weeks or periodised phases of training. In other words, it’s far easier (and logical) to compare heart rates that focused on a single parameter, rather than comparing one run where low heart rate was desired and another where it was, say, speed. Being able to run slightly faster at the same heart rate, or running at a slightly lower heart rate at the same pace, should be celebrated as a win.
5. Don’t Compare with Others
If there’s one mistake that trumps all others that we make, it is to compare our training, data, metrics and progress with others. Whether it’s that random Strava athlete, a friend, an elite, or someone we look up to, it is inevitable but to draw comparisons.
“He just did a 90min zone 2 run at 128bpm - why is mine 154bpm?”
“She ran a 10k at 4:50/km pace and her average heart rate was 164bpm - why was mine 189bpm?”
“Her VO2max is 56 - why am I still stuck at 48?”
The simple answer to these questions is that we’re all different. Our adaptations to training loads are a product of the training programme being followed, our past training experiences, our lifestyles, our biologies, our psychologies - in other words, our adaptations are a result of who, what and where we are.
Which is why even a precise like-to-like training regimen with the exact same lifestyles and the exact same demographics will not give the same results.
And there’s absolutely nothing wrong with having a VO2max of 48 when your Strava crush is at 56. It’s just where we are in relation to our own self. And that’s where comparisons start making sense, when we change the spectrum and look at how our own numbers are trending. Consider these questions as opposed to the ones above:
“My average 90min zone 2 heart rate 6 months ago was 154bpm - has it come down? If not, why?”
“I ran a 10k at 4:50/km pace 3 months ago at an average heart rate of 189bpm - what was it last weekend?”
“My VO2max was 48 a month ago - has it gone up? If not, why?”
By asking the right questions and comparing against individualistic benchmarks, the frustrating journey of lowering the heart rate can be navigated with much more clarity, if not ease.
Conclusion
Low heart rate training need not be complicated. While one can’t avoid the countless walk breaks or the countless pings from the smartwatch, understanding the purpose of these can certainly downplay the mental overload brought about by these factors. Lowering the heart rate for improved running performance is a long game which, above all, needs patience and can not be achieved through shortcuts.
At IronStride, we help trail and ultra runners make sense of running and strength training. We’re just a hello away.
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