How intense does your exercise session have to be?
September 2022   LIFESTYLE HEALTH

How intense does your exercise session have to be?

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By now, the majority of us are more or less familiar with the recommended weekly targets of 150 minutes of moderate intensity exercise or 75 minutes of vigorous intensity exercise, especially from official channels like the Singapore Health Promotion Board1. The underlying message seems simple enough: we should try to work out consistently, or at least for an ample amount of time.

But the reality is that there is rarely enough time in a day to do all the things that we want to do, let alone the things that we should do. This means that oftentimes, we end up taking ‘shortcuts’ for the more unlikable things like exercise. For some of us, this could be falling into the trap of believing that longer, more vigorous workouts are necessary to make up for an inconsistent exercise schedule. For others, it may be thinking that a workout is only beneficial if we sweat profusely, end up incredibly exhausted, or feel sore the next day.

Despite all this, research has consistently pointed out that we do not, in fact, have to spend long hours exercising every session or go all out for every single workout. Instead, any physical activity that can get our bodies moving and hearts beating a little faster throughout the day is already much better than staying sedentary. From the commonly overlooked moderate intensity exercises to the generally preferred vigorous intensity ones, we are breaking down the differences and benefits of each in this article to help you plan for your health goals in a way that can be effective, enjoyable, and sustainable all at the same time.

Knowing your heart rate

It may surprise you to know that the difference between moderate and vigorous intensity exercises does not actually lie with the type of exercise. While the exercises themselves can provide a good indication of how intense or demanding they can be on a person, the real indicator is something that is much more personal to each of us: our heart rates. More specifically, it is various ranges of our maximum heart rate that allows us to gauge whether we are working out moderately or vigorously.

Our maximum heart rate depends on our age. To calculate yours, simply subtract your current age from 220. You can then track your heart rate while exercising to see if its intensity is considered moderate or vigorous. Moderate intensity exercises should put your heart rate at about 50 - 70% of your maximum heart rate, whereas vigorous intensity exercises should get your heart rate up to approximately 70 - 85%. While this method is not precisely accurate, it does offer us a more concrete and quantifiable method of understanding our workouts, as opposed to more arbitrary factors like soreness or exhaustion levels that can vary day to day. If you have yet to try tracking your heart rate when exercising, it might be worth a shot to help you better understand the various benefits you may be experiencing at different intensity levels.

The benefits of moderate intensity exercise

Beyond indications of our heart rate, moderate intensity exercises are typically defined as activities that cause a noticeable but limited increase in both breathing and heart rate. An easy way to check this is to see how hard it is to breathe when working out. If you find it hard to sing but are still able to hold a conversation, then you are likely exercising at moderate intensity.

Generally, these exercises can be achieved by taking a 15-minute walk after meals or even taking a 2–3-minute mini-walk during your work breaks. Exercise snacks like these are usually quick and easy, which means that they can sometimes be overlooked or dismissed as activities that lack any substantial health benefits. As it turns out, they excel in helping us to rack up our active minutes over the day and therefore keeping common health concerns at bay. Moderate intensity workouts, for instance, can significantly reduce the risk of chronic diseases like Type 2 Diabetes by helping to regulate blood sugar levels and lower blood pressure. Further research has also linked them to mental health benefits, such as a lower risk of anxiety2 and insomnia3.

The benefits of vigorous intensity exercise

In comparison to moderate intensity exercise, vigorous intensity exercises ramp up the physical exertion required, which in turn translates to quicker breathing and a faster heart rate. A good indication is when you find yourself experiencing greater difficulty speaking while exercising and can only manage to get a few words out sporadically as opposed to being able to hold a full-fledged conversation. Some more commonly known ways to achieve this are through ‘traditional’ forms of exercise, like jogging, swimming, or even high intensity interval training (HIIT).

While moderate intensity exercise primarily provides benefits for chronic disease prevention and mental health, vigorous intensity exercise goes one step further in remodelling our bodies and getting us in shape. This can refer to improvements in our stamina and cardiovascular health, and even muscle growth in the right scenarios. On a physiological level, these changes can subsequently lead to a greater metabolic rate that is able to burn calories more efficiently. Studies on HIIT, for one, found that participants metabolised fat much better the following day after a HIIT session than if they sat all day without exercising4. If you are not a big fan of HIIT but are still looking to reap the same benefits, pushing yourself to sustain higher speeds during your preferred cardio exercises can be a good alternative to help you achieve the same results.

Over to you

As your lifestyle and health goals change in the future, remember that it is perfectly acceptable to change up your exercise routine to suit your needs and preferences. The best exercise routine is often the one which you enjoy and can sustain over a long period of time, rather than those that are dictated by exercise intensities or current trends. And on the off days when you are struggling to get a workout in, staying on track can be as simple as getting off the chair and getting your body moving with some dancing or light stretches.



1. Singapore Health Promotion Board. (2011). Health Promotion Board launches national physical activity guidelines.
2. Herring, M. P. (2010). The effect of exercise training on anxiety symptoms among patients.
3. Passos, G. S., Poyares, D., Santana, M. G., Garbuio, S. A., Tufik, S., & Mello, M. T. (2010). Effect of acute physical exercise on patients with chronic primary insomnia.
4. Wolfe, A. S., Burton, H. M., Vardarli, E., & Coyle, E. F. (2020). Hourly 4-s sprints prevent impairment of postprandial fat metabolism from inactivity.

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