As you may or may not know, exercise broadly falls into two main categories: cardiovascular training (what we colloquially call cardio,) and strength training, also known as resistance training.

Cardiovascular exercise elevates your heart rate and breathing rate and typically involves sustained periods of activity using large muscle groups and/or many muscle groups. Examples include running, swimming and cycling. This type of exercise is meant to improve your heart and lung health – what we often refer to as cardiovascular fitness.

Strengthening exercises are those which involve exercising a muscle against a resistance, such as by working against machines, cables, barbells and dumbbells. Bodyweight exercises also fit into this category. These exercises are meant to help increase muscle strength, power, size and/or endurance. These exercises are what we picture when we think of the weightlifting area at the gym.

Preferring One Form of Exercise

Perhaps you have a preference for which type of exercise you engage in. Maybe you think cardio is boring. Or you may be afraid of ‘bulking up’ and so avoid lifting weights. But have you ever considered doing both types of exercise?

I might be preaching to the converted, but in my experience, most of us will gravitate towards one type of exercise and try to avoid the other.

Up until recently, I had no idea how important both types of exercise are for us all. I was firmly in the cardio camp. I was a dancer and that was the only form of exercise I did. I remember thinking that lifting weights wasn’t for me. I’d get too bulky and anyway, I didn’t care about looking strong.

That line of thinking was my downfall, because as a dancer, not focusing on your strength creates an almost-inevitable path to injury. Additionally, it was never meant to be about looking stronger, but about being stronger, and by extension, healthier.

Even if you’re not a dancer, though, both types of exercise are so important for you. More recently, the physical activity guidelines have begun to reflect this.

The WHO’s Physical Activity Guidelines

If you’re familiar with the WHO’s minimum physical activity guidelines, you might know that they recommend at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity exercise (or a combination of the two) per week.

But did you know that they also recommend at least 2 sessions of resistance training per week (World Health Organisation, 2020)?

I grew up hearing that adults should do 30 minutes of exercise a day (which roughly adds up to 150 minutes a week if you rest at the weekend) and that children should do 1 hour a day. However, resistance training was never mentioned.

To be honest, it was never really explained to me what exactly I should have been doing during those age-dependent daily 30-60 minutes. But spending that time lifting weights would never have occurred to me. I would have imagined the recommendation to be cardio or team sports.

There’s a fairly good reason for this lack of awareness though. It was only in the 2010s that resistance training began to be added to the physical activity recommendations (World Health Organisation, 2010). And as with all things, it takes time for awareness of these new guidelines to circulate, and even longer for them to be widely implemented.

Why Should You Care?

At this point you might be wondering why you should care. What does it matter if you do just cardio or just strength training?

Well, as I previously mentioned, the aim of both types of exercise is different. This means that engaging in each type of training modality will benefit your body in a different and essential way. Without one of them, you could be neglecting a large part of your physical fitness that could benefit both your health and quality of life.

Benefits of Cardiovascular Exercise

I’ve already highlighted the benefits of exercise on cardiovascular health in my article on exercise and cardiovascular disease, which you can find here, but briefly, here are the main beneficial effects cardio has on cardiovascular health (Chen et al., 2022):

• It significantly reduces cardiovascular risk factors such as body mass index, cholesterol, blood pressure, and blood glucose. These are also risk factors for type 2 diabetes.
• It helps protect the heart from stresses placed on it (e.g. during a heart attack) by boosting its antioxidant capacity and reducing the production of harmful chemicals by the mitochondria during energy production.
• It helps increase the size of the heart in a healthy and reversible way, through heart cell growth and production. It differs from harmful growth of the heart, where there is usually increased heart cell death and fibrosis, leading to stiffening of the heart muscle.
• It stimulates multiple responses in the blood vessels to meet the increased oxygen and energy demands of the heart. These include the activation of nitric oxide (NO) production, which promotes vasodilation (widening of blood vessels) and improved blood flow, as well as the formation of new blood vessels, to support healthy heart growth.
• It improves metabolism of the heart, by enhancing production of mitochondria, mitochondrial function and energy production in the mitochondria using fatty acids and glucose molecules.
• It can help improve overall health. By improving other health markers around the body, such as metabolites in the gut, exercise can indirectly benefit heart health.

As I’ve eluded to in the final bullet point, cardio doesn’t just benefit cardiovascular health. It can help improve the health of so many other organs and organ systems, including the respiratory system, the nervous system and the renal system.

Unfortunately, these are too numerous to mention here and are beyond the scope of this article. However, I soon hope to outline some other ways in which exercise benefits our bodily function in another article. In the meantime, if you’d like to read more on how exercise helps our immune system, you can find that article here, and if you’re interested in finding out how it can impact some of our hormones and body fat distribution, you can find out more about that here.

Benefits of Resistance Training

What about strength training? What benefits does that type of exercise impart?

Once again, I go into a lot more detail in a previous article I wrote which you can find here. But I’ll briefly touch on some of the areas where resistance training can have a positive impact on our health (Westcott, 2012).

• It can reverse muscle loss and help build more muscle even into old age.
• It can boost metabolism in a couple of ways: in the long-term by increasing muscle mass which requires more energy to maintain, and in the short-term by triggering energy-intensive muscle repair for up to 72 hours post-workout.
• It promotes lean muscle gain and fat loss, including reductions in harmful abdominal fat, which you can read more about here. This form of exercise also increases the amount of energy you burn at rest, meaning you can burn more calories even after your workout is complete.
• It can improve physical function, including through contributing to gains in strength, lean mass, and functional independence, along with improvements in movement, physical performance, and walking speed.
• It can help with resisting type 2 diabetes by improving insulin sensitivity and blood sugar levels. Studies appear to recommend higher-volume, high-intensity resistance programs for this.
• It can also improve cardiovascular health through lowering your blood pressure as well as increasing good cholesterol and reducing bad cholesterol levels in the blood. Some studies suggest it can also improve dilation of the blood vessels when blood flow is increased.
• It has been shown to help prevent or reverse bone loss by increasing bone mineral density, particularly in the bones of the legs and spine, but results are sometimes inconsistent.
• It offers notable mental health benefits, including reduced symptoms of depression, anxiety, fatigue, and pain, along with improvements in cognitive function, mood, and self-esteem.
• Finally, circuit resistance training with short rest periods has been shown to improve mitochondrial numbers and function, leading to mitochondrial characteristics similar to those in moderately active young adults. It has therefore been touted as anti-aging.

Conclusion

In summary, engaging in either aerobic or resistance exercise is great for your health – but combining both can offer even greater benefits (Sawan et al., 2023). Each type targets different aspects of physical wellbeing, and together they complement one another to support more balanced, well-rounded health.

So why not try and follow the WHO physical activity recommendations and do 30 minutes of cardio 5 days a week, along with 2 full-body strength training sessions weekly. You might find that you can really feel the difference in your body! Let me know how it goes in the comments, and see you next week for some more exercise tips, tricks and science.

References

Chen, H., Chen, C., Spanos, M., Li, G., Lu, R., Bei, Y., & Xiao, J. (2022). Exercise training maintains cardiovascular health: signaling pathways involved and potential therapeutics. Signal Transduction and Targeted Therapy, 7(1). https://doi.org/10.1038/s41392-022-01153-1

Sawan, S. A., Nunes, E. A., Lim, C., McKendry, J., & Phillips, S. M. (2023). The Health Benefits of Resistance Exercise: Beyond Hypertrophy and Big Weights. Exercise, Sport, and Movement, 1(1), e00001. https://doi.org/10.1249/ESM.0000000000000001

Westcott, W. L. (2012). Resistance Training Is medicine: Effects of Strength Training on Health. Current Sports Medicine Reports, 11(4), 209–216. https://doi.org/10.1249/JSR.0b013e31825dabb8

World Health Organization. (2010). Global Recommendations on Physical Activity for Health. https://iris.who.int/bitstream/handle/10665/44399/9789241599979_eng.pdf

World Health Organization. (2020). WHO Guidelines on Physical Activity and Sedentary Behaviour. https://iris.who.int/bitstream/handle/10665/336656/9789240015128-eng.pdf?sequence=1