“Success isn’t always about “greatness.” It’s about consistency. Consistent hard work gains success. Greatness will come.”
―Dwayne Johnson (The Rock)
Cardio originated from the Greek word kardia meaning heart. In terms of health and fitness, cardio refers to any exercise related to the heart.
It’s not only helpful in losing fat, but it can also help build more muscle over time with the proper amount.
Because cardio increases the blood flow in the body, it can speed up the body’s recovery process.
This type of active recovery enables faster transportation of nutrients required for muscle repair and increases the removal rate of waste that is generated during intense exercise.
To reap the full benefits of active recovery, perform cardio exercises like rowing that target the entire body instead of just legs, like most cardio exercises.
Cardio boosts insulin sensitivity and it is directly correlated to the amount of cardio done.
Having high insulin sensitivity means more insulin is in the body when you introduce food into the body.
Therefore the body will have more muscle growth and less fat storage over time since muscles can absorb the nutrients more efficiently.
Even when strictly looking to build muscle, you can do cardio to increase and maintain your heart health.
Having strong cardiovascular endurance and low resting heart rate are some of the benefits of doing cardio exercises.
Cardio exercises such as cycling or rowing that target certain muscle groups also help you build overall strength and muscle.
Types of Cardio
But how the body uses each differs based on your intensity.
The body uses equal amounts of carbohydrate and fat stores at 60% of your maximum heart rate.
You calculate your maximum heart rate by subtracting your age from 200.
If you’re 30 years old, your maximum heart rate would be 170 and 60% of maximum heart rate is 102.
Low-intensity steady-state (LISS) exercises use mostly fat stores that are at 60 to 70% of maximum heart rate, the “fat burning zone.”
In contrast, high-intensity interval training (HIIT) uses more carbohydrate stores than fat stores.
Based on the body’s utilization of fat stores, you might prefer low-intensity exercises for losing fat.
However, there’s more to it because the number of calories burned by each type of exercises is not the same.
For example, if you spend 60 minutes walking.
You could burn up to 100 calories with 70 calories coming from fat.
But if you spend 60 minutes running (higher intensity), you could burn up to 200 calories and 95 calories are from fat.
The higher intensity exercise burns more fat even though the body used less percent (47.5% vs 70%) of fat stores!
People who performed high-intensity interval training lost more body fat than those who performed low-intensity training.
High-intensity interval training is superior to low-intensity training because of higher:
- Metabolic heart rate for longer than 24 hours after exercise.
- Muscle insulin sensitivity.
- Appetite suppression after exercise.
- Levels of muscle fat oxidation.
- Production of growth hormones including catecholamine (helps with fat mobilization).
In addition to burning more calories than low-intensity training, high-intensity interval training also helps with performance and muscle preservation.
The negative effects of long cardio sessions include strength impairment and hypertrophy.
Therefore it’s beneficial to keep the high-intensity interval training cardio session short (25 to 30 minutes) to maximize fat loss and preserve muscle.
Cardio Exercises That You Should Do
Any exercise that will increase the heart rate can be applied to high-intensity interval training.
Some examples include:
Hill sprints are definitely my favorite and here is how I do it.
- Start off by running one mile (5 to 10 minutes) on flat ground to warm up.
- Sprint up a steep hill for 30 to 60 seconds.
- Rest by walking down the hill for 1 minute.
- Sprint up the same hill for 30 to 60 seconds.
- Rest by walking down the hill for 1 minute.
- Repeat this for 3 to 5 more times.
- Then cool off by running another mile on flat ground followed by some static stretching.
This simple yet intense workout can range from 15 to 25 minutes.
You can do sprints on flat ground if you don’t have access to a hill.
If sprinting is too intense, then replace with jogging or fast-paced walking.
The purpose of high-intensity interval training is to push you out of your comfort zone for a short period while keeping your heart rate high!
If you’re doing it properly, then you will be desperately fighting for air during and after each interval.
Contrary to popular belief, you don’t need to do a lot of cardio to be lean.
Although cardio is not necessary for losing fat, it’s imperative for reaching below 10% body fat.
Two to three sessions of cardio (HIIT or LISS) per week is enough.
Typically I do two high-intensity interval training (in a fasted state) sessions with running and cycling during the week.
If time permits on the weekend, then I would do a third session.
The Best Time to Do Cardio
I usually do cardio exercises in the morning or late afternoon (if performing intermittent fasting).
However, timing does matter when you combine cardio with weightlifting exercises in the same session because it can distort anabolic gene production.
When you do cardio before weightlifting exercises, your body suppresses anabolic hormone production like MGF and IGF-1.
The benefits of MGF (mechano growth factor) include:
- Muscle growth stimulation
- Muscle recovery
- Nitrogen retention
- Muscle fiber generation
- Increase in protein synthesis
IGF-1 (insulin-like growth factor 1) is a hormone that contributes to anabolic growth that helps build bone and muscle mass.
When you do cardio after weightlifting exercises, your body enhances the breakdown of muscle tissue.
To maximize your progress, you should separate cardio and weightlifting sessions with adequate time (at least five hours) if you plan to do both on the same day.
I recommend performing one session in the morning and another at night.
Although not necessary for fat loss, cardio is important for your heart health.
It can also help with building muscle, especially when cardio exercises such as rowing or cycling target certain muscle groups.
High-intensity interval training is far more superior than low-intensity steady state cardio because it burns more calories and fat.
Choose a cardio exercise that you enjoy the most (or hate the least) to increase the likelihood that you will stick to it.
Listen to your body and go at your own pace.
Strive to stretch your comfort zone gradually and consistently.
To maximize progress and results, don’t combine cardio and weightlifting exercises in the same session.
Please share this article with anyone who you think may find it useful.
If you have any questions and/or comments on cardio, please leave a comment below or send me an email.
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Said Ahmaidi, Phillipe Granier, Z. Taoutaou, Jacques Mercier, Hervė Dubouchaud, and Christian Prėfaut, “Effects of Active Recovery on Plasma Lactate and Anaerobic Power Following Repeated Intensive Exercise,” Medicine and Science of Sports and Exercises 28, no. 4 (1996):450-56.
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