Why Cardio Should Be More Than 10% of Your Fitness

After many years of training on my own in my home gym or outdoors, I decided to join a gym in 2025. They offered a complementary Fitness Assessment to all new members, and I surely took advantage of it. However, it was a disappointment in multiple ways, but one of them stuck out the most:

I was told that cardio accounted only for 10% of the total fitness equation.

And even if I absolutely second the idea that strength and nutrition are uber important (I was told 40% and 60% respectively), cardio is extremely important too in my opinion, and this is also what research supports.

I do like thought that strength training is getting a lot of attention nowadays. Strength is vital at any age. First and foremost, a strong body helps us perform daily tasks more easily. For example, carrying our groceries or hoisting our carry-on luggage into the airplane top bin. Strong muscles can ward off exercise related injuries. Furthermore, the older we get, the more critical strength becomes, because it plays a decisive role in our self-autonomy, allowing us to do basic things like standing up from a chair by ourselves.

But let’s go back to the topic of the day, which is cardiovascular exercise. As showcased in my recommendation of just giving cardio a 10% weight in my overall fitness program, I am under the impression that the role of cardiovascular exercise is currently taking a second plane.

The benefits of cardiovascular exercise have been demonstrated over time, and this type of exercise is essential to manage some conditions like hyper lipidemia (high cholesterol and triglycerides), diabetes or pre-diabetes and even to regulate our circadian rhythms.

How cardio exercise helps with cardiovascular health

What is cardiovascular exercise (or just “cardio”) after all? Basically any type of movement, or exercise, that raises our heart frequency to some extent. Brisk walking, running or cycling are common examples. Thus, it stresses our cardiovascular system (mostly the heart) and also initiates a set the metabolic processes in the body to provide the muscles with the energy required to sustain the movement. And all this has wonderful results on our health, mainly due to the adaptations that our wise body makes to overcome the stress.

Cardiovascular exercise:

• Combats chronic inflammation through multiple mechanisms.
• Lowers total and LDL cholesterol levels.
• Increases the production of antioxidants, which are key to defend us from oxidative stress. Atherosclerosis is greatly caused by oxidation of LDL cholesterol particles deposited on arteries walls. So protection against oxidation is protection against atherosclerosis.
• Increases the size of the LDL cholesterol particles. Larger particles are less probable to attach to arteries walls and therefore cause atherosclerosis.
• Helps keep a health body weight, as movement requires that our body generates more energy to sustain it (burn calories). Depending on the intensity of the cardio exercise, you can keep burning more calories a few hours after your exercise session. A healthy body weight is associated with better health and can prevent conditions like metabolic syndrome.
• Helps prevent and treat type 2 diabetes, again due to the energy needed to generate the movement. Both sugar and fat can be used for fuel, depending on the intensity and duration of the exercise.
• Helps reduce the risk for some types of cancer, including colon and breast.
• Protects your brain cognitive function, including dementia.
• And more!

Do we really need to separate strength and cardio?

Traditionally, we have associated cardio to activities like brisk walking, running, cycling, gym machines like elliptical or row, or group classes like Zumba or step. On the other hand, strength is related to dumbbells, elastic bands, weight gym machines or body weight. This is a good approach for everyone, especially for beginners.

But the good news is that anything that raises your heart rate is cardio. So, if you are doing circuit style strength training and your heart is beating hard, that accounts for both strength and cardio. If you do a couple of strength training exercises followed by a cardio burst, that accounts for both types of exercise as well. Multi-articular strength moves (compound moves) usually rise heart rate too if rests between exercises are kept short. Bootcamps and crossfit are also good examples of disciplines that work strength and cardio.

Thus no, we don’t necessarily need to separate strength from cardio.

Is all cardio the same?

No, basically there are two types: steady and interval.

• In steady, you raise your heart rate to a level, let’s say 75% of your maximum, and keep it there for the duration of the exercise.
• In interval, the heart rate fluctuates up and down. Both types provide different benefits, so the best approach is to incorporate both in our weekly exercise schedule.

Bootcamps, circuit training, crossfit and cycling (spinning) classes are examples of interval cardio. A brisk walk or a jog at a set speed is an example of steady, low intensity cardio. A walk that alternates 1 minute at relaxed pace with 1 minute at faster pace is interval training. HIIT (High Intensity Interval Training) is a type of interval training, and these workouts tend to be short. On the contrary, steady cardio sessions are lower in intensity but usually longer in duration.

Current exercise recommendations

The CDC recommendation for adults is at least 150 min of cardio and 2 days of strength training each week.

Your best fitness plan

The best fitness plan is the one that is tailored to individual needs, goals and health conditions, but strength and cardio should be part of it. Ideally, both steady and interval cardio should be performed. For time constrained people, disciplines that combine all (like bootcamps) might be the best choice. This article does not discuss mobility and flexibility, but they also should have a place in our routine. And of course rest, at least one full rest day per week. This is when the magic happens, when we give our bodies time to adapt to the stress we are generating with exercise.

Here is a basic example of a weekly schedule for an individual that is already exercising and does it for health and longevity reasons. I personally follow a routine very similar to this:

Monday	Tuesday	Wednes.	Thursday	Friday	Saturday	Sunday
Rest	20-30 min steady cardio. Core work (yoga or Pilates)	Full body strenght, circuits (interval/HIIT)	30-40 min steady cardio. Stretch or yoga	Rest	45-60 steady cardio	Full body strengh. Stretch or yoga

Your call to action (pun intended)

I encourage you to consider the current cardio exercise recommendations for optimal health and well being. Really any reason that moves us in the right direction (pun intended too!) is valid: weight loss, stress management, socialization, longevity, looking good. Really, anything. If you have a why – your why – you can do anything.

For those already exercising, it might be a good idea to review your current plan and check if cardio is covered, and adjust as necessary. For those new to exercise, please start small and progress towards the recommendations.

If you are up to, I invite you to make a commitment with yourself and create a cardio exercise SMART (Specific Measurable Achievable Relevant Time-bound) goal for this week. For example:

• I will go for a 30 minute brisk walk 3 times.
• I will join a bootcamp class 2 times.
• I will start the Couch to 5k plan this week.

Lastly, we all have bad days when we don’t feel like exercising, and that’s OK. Consistency is king; as long as you are following your plan most days, you will succeed.

And by the way, I did not sign up for that fitness program that diminished cardio to a 10%.