To Maximise Your Workout, Monitor Your Exercise Intensity
You’ve painstakingly found time to focus on your health and fitness. Now, make every minute count.
When we exercise, it is important to measure and monitor the intensity of our workout. Many of us struggle to find time to exercise, so when we do find the time, we want to maximise the fitness benefits we gain from each session. To achieve this, our workout sessions need to be purposeful and focused. One common mistake that people starting their fitness journey make is exercising aimlessly without clear objectives. As such, many likely exercise way harder than they should. When we begin our fitness journey, most of us probably think:
“The more intense the workout and the harder I work, the more I gain out of the workout!”
Even seasoned athletes unconsciously hold on to the belief of No Pain, No gain. I am guilty of this sometimes. But this approach to fitness is inherently flawed and unsustainable.
Different exercise intensities impose different physiological stresses on the human body, which in turn yield different benefits as the body adapts to these stimuli. Therefore, the first step is to be clear about our fitness and session objectives. We need to pre-determine the exercise intensity required to achieve these goals. It is important to strike a balance between working at too high of an intensity for too often, which can lead to fatigue, and working at too low of an intensity, which may not provide enough stimulus for the physiological adaptations and benefits we intend.
Ideally, we want a mix of easy and higher intensity sessions. Measuring and monitoring exercise intensity during our workouts is crucial to ensure that we do not get carried away and push ourselves too hard or not hard enough. This process may sound complicated, but it does not require a PhD to make it work. This article aims to simplify the process of measuring and monitoring your workout efforts so that, regardless of the activities you engage in, you can have a purposeful and effective workout.
What are the measures of intensity during exercise?
When it comes to measuring exertion and exercise intensity, there are both internal and external measures to consider. Internal measures, such as heart rate (HR), rate of perceived exertion (RPE), and the talk test, focus on the body’s physiological response to exercise. These measures are unique to each individual and can provide valuable insight into how hard the body is working during physical activity.
On the other hand, external measures, such as speed, power, and force, focus on the work done and resultant output of the body. These metrics are tangible and can be easily quantified, providing a more objective perspective on exercise intensity.
Common methods of monitoring exercise intensity during aerobic exercise are heart rate, rate of perceived exertion and pace. As for resistance/strength training, the weight lifted, percentage of 1RM (the maximum weight you can lift for just once), and RPE can be used to quantify the intensity.
For the purpose of this article, we will be focusing on the metric used for aerobic exercise. Resistance exercise session are generally more structured and pre-planned and hence, intensity during lift are usually consistent. The mistakes many face during resistance exercise is planning and managing the training volume. We will dive further into this in another article. (comment if you are interested!)
Exercise heart rate is a popular method that involves keeping track of your heartbeats per minute during exercise. This can be done using a heart rate monitor or checking your pulse manually. RPE, on the other hand, is a subjective measure of how hard you feel like you’re working during exercise. It’s based on a scale of 1 to 10, with 1 being very light activity and 10 being maximum effort. Lastly, monitoring pace involves keeping track of the speed at which you are completing a specific exercise, such as running or swimming. By utilising these methods, you can tailor your workouts to match your fitness goals and ensure that you are working at an appropriate intensity level for their desired outcomes.
Both internal and external measures have their own merits and can be used in conjunction to get a comprehensive understanding of exertion and exercise intensity. For example, when we are fatigued or recovering from a common cold, your exercising HR and its corresponding running pace may deviate from your usual trend. For a given pace you are running at, you observe that your HR is 20–30 beats higher than usual. You can even feel that you are working harder this session just to maintain the intended pace too. This is a sign that your body is withstanding a greater physiological stress just to maintain the same performance. Perhaps, it’s a clue that you should take it easy or have the day off to recover.
At the end of the day, there is a myriad of ways to monitor the intensity of your exercise. You should choose one that is accessible to you and provides the least hassle as you to sweat it out. HR, pace/speed and perceived exertion are simple, accessible and easy to use methods, hence, their popularity.
Which method should you choose?
I prefer to monitor internal measures of exertion, specifically, HR and RPE. The reason I prefer internal over external metrics are threefold. First, internal measures account for fluctuating conditions and take into account fatigue. When we rely solely on external metrics, such as power or pace, we may overlook the influence of factors like weather, stress, or fatigue on our performance. Internal metrics, on the other hand, provide insights to my physical state and allows for adjustments to my training session.
Second, internal metrics allow me to focus on the experience and performance of the workout, promoting mindfulness. By paying attention to how our body feels during exercise, we can adjust our workout based on our body’s response to the session, leading to better results and reduced risk of injury.
Lastly, internal metrics can better align with our long-term fitness and wellness goals. Instead of fixating on external markers of success, like beating a personal record or outperforming others, internal metrics help us focus on the overall improvement of our physical and mental well-being.
Remember, you are more likely to keep doing what you enjoy. So immersing yourself in the workout and having fun is the key to long term fitness gains.
Only two parameters you need to monitor
I personally focus on the combination of Heart rate (HR) and Rating of Perceived Exertion (RPE) when it comes to monitoring my fitness and performance. I love and predominantly use the RPE during my workout. It’s low tech and requires no additional equipment at all. The only thing I need to care about when using the RPE is “How effortful do I feel?”. It can be liberating to rid exercise of all its complexity and fuss. Instead, central to any effective and productive workout is simply being present and awareness of self. This freedom is hard to come by in our increasingly complex world, and we sometimes forget that people exercise just fine before the advent of any smartwatch or training tech.
I do wear a Garmin Smartwatch that provides me with a wealth of data and metrics, but in my opinion, they are non-essential for my workout. I’m just a nerd when it comes to fitness and training, and I enjoy analysing my sessions post-hoc.
RPE is great for monitoring my effort, providing real-time feedback on how hard I feel I am working during exercise. On the other hand, HR monitoring is fantastic for post hoc analysis and progress tracking, allowing me to see how my heart rate responds to different levels of exertion over time.
What’s even better is that these two metrics correlate strongly with each other, giving us a more comprehensive understanding of our workouts. By taking both RPE and HR into account, we can tailor our training sessions to our individual fitness levels and goals, ensuring that we push ourselves enough to make progress without overdoing it. The combination of these two measurements allows us to make more informed decisions about our workouts and ultimately, helps us to achieve our fitness goals more effectively.
How to monitor HR during exercise?
Heart rate monitors offer real-time feedback on the intensity of exercise, allowing individuals to make immediate adjustments to their workout intensity levels. HRM are an essential tool for anyone looking to maximize their workouts and achieve their fitness goals. One of the biggest benefits of using a heart rate monitor is the real-time feedback it provides on the intensity of your exercise. This feedback allows you to make immediate adjustments to your workout intensity levels, ensuring that you are achieving your target HR. So, if you’re looking to take your fitness to the next level, investing in a heart rate monitor is a no-brainer. With the advent of smartwatches and declining cost of basic HRMs, they are becoming more ubiquitous. You can easily find an affordable HRM that serves your purpose. However, that’s not to say that HR monitors are an absolute necessity for a fruitful workout. You can still exercise at the right intensity by monitoring your perceived exertion.
Calculating target heart rate
Referring to a target heart rate chart assists individuals in understanding their optimal heart rate zones for different levels of exercise intensity. Your target heart rate is the range at which your heart should beat during exercise in order to achieve the most effective cardiovascular workout. Most target HR ranges are derived from fractioning the maximal HR into percentages, such as 60–80% for moderate intensity and 80–90% for vigorous intensity. There are various formulas for deriving at maximal heart rate (HR), including the popular 220-age formula, but based on my experience and validating research available, these formulas are notoriously erroneous and may not be reliable for individuals with certain health conditions or on certain medications. The gold standard for determining your true maximal HR is to perform a maximal exercise test, such as a cardiopulmonary exercise test (CPET), which measures your oxygen consumption and heart rate response to exercise. However, this test can be excessive for recreational exercise purposes and is usually reserved for individuals with specific performance or medical needs.
Factors known to influence heart rate
Various factors significantly influence heart rate, particularly during exercise. One of the primary factors is the level of physical activity or fitness. The heart pumps more blood during exercise to supply the required oxygen to the muscles; thus, the heart rate increases. The intensity, duration, and type of exercise directly affect the HR. For example, a high-intensity workout would cause a sharper increase in heart rate compared to a low-impact exercise. Age is another factor; as one gets older, the maximum attainable heart rate typically decreases. Body size can also influence HR, with individuals of larger body size possibly having a higher resting heart rate. Psychological factors such as stress and anxiety can also make the heart beat faster. Even the time of day can affect it; typically, the heart rate is lowest while sleeping and gradually increases throughout the day. Certain medical conditions, such as high blood pressure or cardiovascular disease, can alter the HR. Additionally, stimulants such as caffeine and nicotine can temporarily increase heart rate. These factors are critical determinants in maintaining a healthy heart rate, especially during exercise. Hence, your HR at a given intensity is uniquely yours and no two person will have the same heart rate response to exercise.
How to find your target HR zones
In general, it is important to listen to your body during exercise and find a target heart rate range that feels challenging but sustainable for your fitness level and health status. Therefore, it’s always monitoring RPE, RPE, RPE, during workout for me. One method to figure out your target HR is via a maximal effort test, like a sprint protocol. This requires you to perform an exercise, such as a sprint, at your maximum capacity while wearing a heart rate monitor (HRM). The highest recorded heart rate during this strenuous activity is then considered your maximum heart rate. You then divide your maximal HR into percentage ranges i.e. 60%-80% of maximal HR for moderate intensity. It must be noted that this protocol is quite demanding and may not be suitable for beginners or individuals with health concerns.
An alternative method involves analysing heart rate data from previous runs. Here, the goal is to identify distinct heart rate ranges corresponding to different intensity levels. This means you need to run at varying intensities and make sure to log both the pace and the sense of effort felt during each run. This process can be repeated across multiple runs to collect sufficient data. It’s important to maintain a steady effort level during these runs to ensure the reliability of the data.
Over time, a pattern will begin to emerge. For each perceived intensity level or perceived effort, your heart rate will typically fall within a specific range. For instance, you might notice that a low-intensity jog causes your heart rate to stay within the ‘easy’ range of 120 to 140 beats per minute (BPM), while a high-intensity sprint pushes your heart rate into the ‘maximum effort’ range of 180 to 190BPM. This retrospective analysis not only provides you with a spectrum of heart rate zones corresponding to different intensity levels but also personalises your training as these zones are specific to your physiology and perceived effort.
Both methods present their own advantages and their use largely depends on individual fitness, preferences, and goals. The maximal effort test can provide a more scientific and precise measure of your physical capabilities, while the retrospective analysis allows for more flexibility and gradual adaptation to different intensity levels. Ultimately, reliably determining your target HR can greatly assist in tailoring your training plan and ensuring you’re working at the right exercise intensity each session.
How to use Rate of Perceived Exertion?
The Borg Scale for measuring Perceived Exertion is a subjective way of measuring how hard you feel your body is working during physical activity. The scale ranges from 0 to 10, with 0 representing no exertion at all and 10 representing maximum exertion. At 0 on the scale, you should feel as if you are completely at rest, while at a 10, you should feel as if you are at your maximum effort. Point 0 on the Borg Scale should feel like you are sitting down and doing nothing, with no effort at all. As you move up the scale, each point should feel like a gradual increase in effort, with 3 feeling like you are just starting to feel any exertion, 5 feeling like a moderate level of exertion, and 7 feeling like a strong level of exertion. Understanding the Borg Scale can help individuals with pacing themselves during physical activity, enabling them to better monitor and adjust their level of exertion for improved performance and reduced risk of injury.
0/10 rating — Resting
3/10 rating — Starting to feel some exertion
5/10 rating — Moderate effort
7/10 rating — Hard effort
10/10 — Maximal effort
The RPE rating also correlates to different exercise zones, with Zone 2 typically falling around a 3–4 on the scale, tempo efforts around a 5–6, threshold efforts around a 7–8, and anaerobic efforts around a 9–10. This correlation can help you determine the appropriate intensity for their workouts and make adjustments as needed.
The RPE scale helps individuals estimate exercise intensity by assigning a numerical value to their perceived exertion, enabling effective intensity monitoring. This simple yet incredibly effective tool allows you to accurately gauge the intensity of your workouts by assigning a numerical value to your perceived exertion. By using the RPE scale, you can easily monitor your intensity and make necessary adjustments to ensure that you are always exercising at your pre-determined intensity, already taking into account daily fluctuations in motivation, fatigue and energy levels. Whether you are a beginner or a seasoned athlete, the RPE scale can be central to you having an effective and purposeful workout.
The commonly overlooked aspect of exercise when beginners embark on their fitness journey is the intensity which they exercise at. Beginners tend to exercise without pre-set parameters or mindlessly without intent. The greatest penalty is the potential fitness gained from having an efficient and purposeful session. It takes a great deal of discipline, commitment and determination to make time to exercise, especially for busy professionals. If that is the case, every minute should count and maximised to garner the greatest health benefit.
The simplest way, I feel, to introduce intent and focus to one’s workout, is to monitor exercise intensity by rating the perceived exertion. It encourages you to immerse yourself in your workout and practice mindfulness. HR monitors or smartwatch can supplement other valuable data that informs your training but they are optional, and can be good next-upgrade. So, start off with the basics, listen to your body, have fun with it.
