The bodybuilding and fitness community loves this debate. Both sides are arguing on which workout type is best, and which type you can eliminate from your training regimen. However, the debate is frankly pointless. Cardio and strength training don’t have to be mutually exclusive – they can be done in combination.
Research has shown that both types of training need to be incorporated into a training program if it is to produce the best possible results in terms of physique development, not to mention improved heart health, body composition, and longevity. The fact is that these two complement each other.
Many actions that we take during our daily routines rely on having an efficient cardio-respiratory system as well as developed musculature. Examples are numerous: playing with your kids, walking your dog, or running to catch the bus are actions that rely primarily on aerobic fitness, while carrying groceries, lifting furniture, getting up off the ground and doing home repairs rely more on muscular development. It may come off as a surprise, but this is also true for an activity such as taking the stairs – muscular strength has a much bigger role than cardio in determining whether you can endure a whole flight of stairs without breaking a sweat or getting winded.
For the majority of people, the choice between the amount of time one needs to devote to cardiovascular exercise against resistance training depends on what the individual enjoys most. From a health perspective, it’s safe to say that the best exercise is the one you enjoy doing and will continue to do. Having said that, the right workout for each individual will depend on their fitness goals and individual health. Below, you can read about the unique benefits that cardiovascular and strength training provide and how to get the best of both.
How Each Type of Training Affects Muscle
Muscle cells, also known as muscle fibers, are divided into two main categories: type 1 (also known as slow-twitch or aerobic) and type 2 (known as fast-twitch or anaerobic). When doing low-intensity cardiovascular exercise lasting longer than a few minutes, the body generally uses type 1 muscle fibers . The fibers that are directly engaged are the ones that adapt to stress.
The way they adapt is by increasing the number and size of mitochondria – the tiny oxygen-using power plants which provide the necessary energy to your muscle cells – as well as capillaries, the small blood vessels which bring nutrients to the body’s tissues, including oxygen, whilst removing carbon dioxide and many other waste products. All of these adaptations are meant to increase the endurance of the muscle.
On the other hand, high-intensity cardiovascular exercise at a high speed, as well as high-intensity strength training, primarily works the type 2 muscle fibers , even though such types of exercise also work type 1 fibers to a smaller extent. The process of muscle fiber adaptation is known as hypertrophy – the scientific word for muscle growth. The contractile elements of each muscle fiber grow, which results in the entire muscle becoming larger. As these contractile elements grow, the whole muscle is better able to contract, which results in increased power and strength.
How Each Type of Training Affects Body Fat
All types of training decrease body fat levels by using available stores of energy. Cardiovascular training, especially the steady-state low-intensity type, decreases body fat levels by spending calories. The main training variable which determines how many calories you’ll burn during your workout – regardless of the type of training – is intensity.
In a study published in the 2013 Journal of Sports Science & Medicine, participants who did a 20-minute interval strength workout session which included burpees, push-ups, lunges, and squats burned an average of 15 calories a minute – almost twice the expenditure of a long jog. The higher the training intensity, the greater the number of calories burned during training. Additionally, it’s been found that the body burns even more calories after training as its physiological systems recuperate – also known as excess post-training oxygen consumption (EPOC). It is a great bonus to your training.
It’s worth noting that even though high-intensity training is just a small part of the overall caloric expenditure, it is still important. However, high-intensity strength training is unique in that it has an indirect effect on fat loss by increasing lean muscle mass. Lean muscle tissue increases the overall metabolic rate, which enables you to burn more calories in the long term, both during and after your workouts.
There was a study done in Harvard examining obesity. It followed 10,000 male participants for 12 years. Researchers found that the men who did any kind of resistance training gained less fat around their abdomen compared to the men who spent the same amount of time each week doing conventional cardio workouts. Related: Does Cardio Burn Muscle? The Complete Guide
Cardiovascular Health: Where Cardio Has the Edge
It is quite logical that with a name such as “cardiovascular exercise,” this type of training would have great benefits for your heart’s health. However, it is also important to note that all types of training increase the workload on your heart and lungs and can be deemed cardiovascular to a certain level. Even though “cardiovascular” is the most common term, “aerobic” is the more scientifically accurate term for physical activities like cycling and jogging.
Both activities have been proven to offer lots of benefits. Of the two, cardiovascular or aerobic exercise has a greater direct impact than strength or anaerobic exercise, since it builds aerobic fitness more effectively – the body’s ability to efficiently transport oxygen to tissues and use it. A 2011 study published in The American Journal of Cardiology concluded that aerobic training is the most effective form of training for improving cardiovascular and metabolic health.
On the other hand, strength or anaerobic training and all the neuro-muscular adaptations that occur with it have a more indirect impact on your heart health. Indirect means that by increasing the amount of muscle mass, you give the cardiovascular system more physical volume to store blood, which in turn decreases blood pressure on the walls of your arteries. By decreasing visceral fat levels, strength training also greatly decreases the risk of heart disease. Regardless of body fat percentage, having excess visceral fat drastically increases the risk of cardiovascular disease, according to a 2016 study published in the Journal of the American College of Cardiology.
Another study done the previous year identified grip strength – a widely recognized indicator of whole-body muscle strength – as a more accurate predictor of the likelihood of death by heart disease than blood pressure. Related: How Much Cardio Do You Need to Lose Fat and Build Muscle?
Longevity: Which Training Type Adds More Years?
A 2014 study published in the Journal of the American College of Cardiology concluded that running just 10 minutes a day at a slow speed significantly decreased the risk of death from all causes. When comparing both types of training, it’s been found that an individual performing only cardiovascular training and no strength training would be more likely to increase their lifespan compared to someone who only does strength training. In any case, people should be encouraged to do both forms of training, since they fully complement each other.
This is especially true for older people whose overall health depends on adequate levels of balance and strength in order to prevent falling accidents and all the complications which result from fall-related injuries. That’s because according to the Centers for Disease Control and Prevention, falling accidents are the number one cause of injury and death among the population aged 65 and older.
Recent studies have shown that maintaining muscle mass as you get older – for which you need to lift weights – is among the leading indicators of how long you’ll live and how much health you’ll have in those years. A 2017 study found that when it comes to measuring overall health, lean muscle mass is a better indicator even than the body mass index.
Both types of exercise have their own unique benefits and they work quite well when combined together. For the complete picture on how strength training specifically affects aging at the gene level, and why resistance training may directly extend your lifespan through myostatin: 10 Reasons Why Lifting Is Better Than Cardio.
The Verdict: Use Both
There is no single winner here – the question isn’t which one to do but how to combine them intelligently. Use strength training as your primary tool for body composition, metabolic health, and longevity. Use cardiovascular training to support your heart health, improve endurance, and accelerate recovery. Neither is dispensable and neither replaces the other.
If time is genuinely limited and you can only do one, the research favors resistance training for overall body composition and long-term health outcomes. But the best program is the one that includes both, structured around your goals and what you’ll actually stick to.
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The gym is full of fat weight lifters that never do cardio.