The Perfect Workout®

The Perfect Workout official logo

Fitness Insights

Real health and wellness wins
and how to achieve them yourself

Cardio vs Strength Training

Strength Training actually is cardio when performed correctly and intensely…
Cardio vs Strength Training - female running and a female performing 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.

To speak with a Personal Trainer about exercise, nutrition or any help with lifestyle adjustments please call us at (888) 803-6813.


More Articles