Cardio vs Strength Training

Cardio vs Strength Training:

Cardio vs Strength Training:

Female running and a female doing a lat pulldown exercise

What is Cardio, Anyway?

The term “cardio” is short for cardiovascular, as in the cardiovascular system, which is a closed network of organs and vessels that are responsible for circulating blood.

Cardio is also similar to “cardiac,” which means “related to the heart.”

When we use the term cardio to describe exercise, it usually refers to activities that people often call “aerobic exercise,” such as cycling, running, and swimming.

Many people exercise to improve their cardiovascular system. When you exercise the muscles in your body, particularly the larger muscles, blood flow increases.

This increase in heart rate and blood flow stimulates the capillaries in the bloodstream to expand. This expansion allows for more oxygen to enter the blood making your heart more effective in removing waste and toxins from the system.

Why is this a benefit?

By supplying the heart with exercise, you reap the cardiovascular benefits such as:

  • Increase in exercise tolerance
  • Reduction in body weight
  • Reduction in bad cholesterol (LDL & total)
  • Increase in good cholesterol (HDL)
  • Increase in insulin sensitivity
  • Reduction in blood pressure

A traditional cardio workout like walking and running do cause effects that increase blood flow and affect the heart, but they aren't the only way to address the cardiovascular system. And they certainly aren’t the most efficient.

Strength training, when applied effectively, is also cardio. Find out more…

Trainer coaching male member on the chest press machine

What is Strength Training?

Generally speaking, strength training is a type of exercise using your body weight or added resistance to build muscle and strength.

More specifically, high-intensity strength training (what we use at The Perfect Workout) is a stimulus that causes a response from the body, and a certain amount of time and recovery is needed for the body to benefit from the stimulus.

If you train at The Perfect Workout, you know how this type of exercise goes:

  • You perform several slow repetitions
  • Your trainer coaches you on the correct form
  • The burn in your muscles continues to increase

Eventually, you start a repetition that you cannot finish. You still push or pull with your best effort, then place the weight down when it is apparent that you're unable to move the weight any further.

According to research, that last detail is the key cardiovascular aspect in your training [2].

Performing weight training exercises to complete fatigue (the point we call muscle success) is the key to unlocking those positive cardio effects.

The article that identifies muscle success as the critical element is a review of 157 studies, most of them pertaining to strength training interventions where “muscle success” was achieved. The article was broken down into acute and chronic effects.

Among the short-term findings, the researchers said that the magnitude of blood flow increase from strength training is related to the intensity (with intensity meaning how deeply the muscles were fatigued): the greater the intensity, the greater the resulting increases in blood flow.

Therefore, training to complete fatigue is the most effective way to increase blood flow with strength training.

For example, one 13-week study of resistance training to complete fatigue increased blood flow by about 55% in the upper thigh and hip region of seniors.

Female member doing the compound row while being coached by a female trainer

Strength Training IS Cardio (when done properly)

That’s right. Strength Training is cardio when performed correctly and intensely.

Another confirmation that training to muscle success results in cardio benefits is that it converts type IIx muscle fibers to type IIa.

What does that mean?

Type IIx fibers have a moderate ability to use oxygen and are not very dense with blood vessels.

On the other hand, type IIa fibers have a high capacity for oxygen and are denser with blood vessels.

So, strength training to complete exhaustion physiologically transforms your muscular system to become more effective at increasing blood flow and using oxygen.

A more significant measure of cardiovascular health is the magnitude that arteries can expand to when blood flow increases. This ultrasonic and noninvasive measurement is called “flow-mediated dilation.”

If plaque is present in an artery, a heart attack can simply be avoided if the artery can expand enough to let the necessary amount of blood pass through.

Therefore, having an artery that can dilate well above its normal size is a significant way to avoid both heart attacks and strokes.

Improving flow-mediated dilation is also beneficial for individuals with rheumatoid arthritis (RA). This is because the inflammation of RA can make the blood vessels on the heart’s surface narrow instead of opening properly, also called endothelial dysfunction, a type of coronary artery disease (CAD).

Strength training to “muscle success” improves flow-mediated dilation.

This was demonstrated in a 13- week study in which the arterial benefits were seen after six weeks [3].

Male member being coached by a male trainer on how to do abduction exercise


Knowing all of this information is great, but how does it help you?

No matter your fitness goals, it means your strength training sessions can provide significant cardiovascular benefits… if used correctly. Instead of avoiding complete fatigue due to the required effort and “burn,” embrace the opportunity!

Increasing temporary and long-term blood flow, converting your muscles to more vascular and oxidative organs, and allowing your arteries to become more heart attack and stroke-resistant are best achieved by fatiguing all the way down to muscle success.

So don't train to complete fatigue because your instructor is recommending you to; train to fatigue because it's in your heart's best interest.

  1. Pate RR, Pratt MP, Blair SN, et al. Physical activity and public health: a recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA,. 1995; 273: 402–407.
  2. Steele J. Resistance Training to Momentary Muscular Fatigue Improves Cardiorespiratory Fitness in Humans: A Review of Acute Physiological Responses and Chronic Physiological Adaptations. 15: 3: 53-80, 2012.
  3. Rakobowchuk MM. Endothelial function of young healthy males following whole body resistance training. 98: 6: 2185-2190, 2005.

Your Muscles – The Only “Window” Into Your Body

your muscles - the only "window" into your body

I first came across the idea that “muscle is the ‘window’ into your body” in Ken Hutchins’ SuperSlow Technical Manual. He attributes the quote to a former employee of Nautilus, Ed Farnham. It’s a brilliant metaphor. The idea is that essentially all physical improvements that can be stimulated by exercise are fundamentally caused by loading your muscles. Making your muscles work is the way you “get at” and stimulate not just your muscles, but the rest of your body’s systems too. Your muscles are a pathway to improving your cardiovascular system, lungs, endocrine system, immune system, general metabolism, and more.

For example, suppose somebody is climbing stairs for the purpose of exercise. This person’s body will temporarily burn more calories during the stair climbing session. It’ll also make her heart beat faster, and by doing so potentially place positive stress on her cardiovascular system to improve. And if the stair climbing is challenging enough, her leg muscles will fatigue somewhat as well. If her body isn’t already used to a more demanding stress than stair climbing (such as high-intensity strength training), her body will be stimulated to improve the cardiovascular system, her muscles might get slightly stronger, and other positive adaptations may occur in such places as the immune system and the endocrine system.

Note that each of those effects from stair climbing (burning calories, positively stressing the cardiovascular system, potential strength increases, and positive changes in the immune and endocrine systems) are caused by making the muscles work. Extra calories are burned only because the leg muscles are working harder from the activity. The heart starts beating faster to supply nutrients to the working muscles, as well to remove waste products from them. If an increase in strength is stimulated, it would be because the muscles have been loaded, fatigued, and stressed sufficiently. All the physical benefits are fundamentally caused by making the muscles work.

Demanding muscular loading is the fundamental cause for triggering a cascade of positive changes throughout your body. Even for the cardiovascular system, the stimulus is making the muscles work, and the cardiovascular system kicks into higher gear simply as a support system for the working muscles. (In other words, the heart and lungs can’t jump out of your body and hop on the stair climber to exercise themselves. The only way to “get at” your cardiovascular system through exercise is by making the muscles work.)

A big advantage of effective strength training when compared with other exercise methods (like stair climbing) is that strength training gives you the opportunity to make your muscles work much harder than stair climbing or other exercise choices. If you’ve ever trained your leg muscles to “momentary failure” on the leg press machine in slow-motion form, you know firsthand how strength training works your muscles hard! Since strength training can make your muscles work harder than other activities (like stair climbing), you can stimulate as good or better benefits in all of the body’s systems (including the muscles, cardiovascular system, lungs, endocrine system, immune system, and general metabolism) than you can with other activities.

In a previous article I mentioned that studies show that effective strength training produces positive benefits in the cardiovascular system. This is why. In some studies with very high-intensity strength training, the changes in the cardiovascular system from strength training are superior to even so-called “cardio” activities like stair climbing. The reason is you can only address your cardiovascular system by making your muscles work, and strength training gives you the opportunity to really challenge your muscles, and as a result many other systems in your body improve in addition to the muscles.

Making your muscles work hard during strength training triggers a “total body response,” including:

  • More strength
  • Greater endurance
  • More calorie-burning lean muscle tissue to your body
  • Reversed age related muscle loss (sarcopenia)
  • Increased metabolism and how many calories you burn even while you’re resting
  • Greater fat loss
  • Stronger bones
  • Reversed aging of muscle cells (expresses younger DNA in the nuclei)
  • Improved cardiovascular fitness
  • Improved cholesterol levels
  • Lowered blood pressure
  • Improved low back pain
  • Better control of blood sugar
  • Improved immune system
  • A number of other benefits

When done properly strength training loads the muscles (your “window into your body”) much more effectively than other activities because strength training can load the muscles more efficiently, more intensely, and in a safer manner than other activities can.

The slow-motion, high-intensity strength training that we teach at The Perfect Workout is as good of a way as you will find at stimulating this “window” into your body, and as a result your whole body improves, not just your muscles. And all it takes is just 20 minutes, twice a week.