Many years ago, while I was competing at a USA Powerlifting competition, Michael Overdeer, then the president of the organization, said a profound statement to me: “Did you ever notice that those who train with heavy weights have better looking skin and look more alive than those who just do cardio only?”

As I looked around the competition warm-up room at all the lifters from different age groups, he was generally correct. At the time, I was a new chiropractic physician who had tons of book knowledge still floating around in his cerebral cortex, and Michael’s statement made me stop and think.

Through my training as a physician and an EMT, my brain started to process this. There is a little-talked-about action that constantly occurs in the body, and that greatly increases when our pulse rate and blood pressure rise. This action is called perfusion.

What Is Perfusion and Why Does It Matter?

Perfusion is defined by Merriam-Webster as forcing a fluid through (an organ or tissue) especially by way of the blood vessels.

In working with my patients and training clients, I not only discuss the benefits of exercise, but I also make sure to talk about the combined benefits of cardio and strength training. Whether the latter includes barbell, kettlebell, or bodyweight exercises, there needs to be some form of resistance training involved in every person’s regimen. The infinite benefits of performing one or a combination of these three types of training include increased strength, bone density, joint stability, improved proprioception, and better blood perfusion.

During my life, I have not found one disadvantage from being strong. However, there are many disadvantages for being weak or not so strong. Decreased blood perfusion is one disadvantage that can affect many tissues and structures for years to come.

When lifting something heavy, say for sets with reps from one to five, it requires you to greatly increase the amount of tension—namely intra-abdominal and intra-thoracic pressure (IAP and ITP) in the torso—to protect the spine, et al. In doing so, your blood pressure will increase dramatically for a short time while this increased tension is happening.

Capillaries, as defined by the American Heritage New Dictionary of Cultural Literacy, 3rd Edition, are the tiny blood vessels throughout the body that connect arteries and veins. Capillaries form an intricate network around body tissues in order to distribute oxygen and nutrients to the cells and remove waste substances.

These tiny capillaries, whose diameter is close to or smaller than that of a human hair, will be infused with more blood during this short time of increased pressure then they normally would in a sedentary moment, thus forcing more nutrients into these areas. Skin, nails, discs, and all connective tissues (i.e. muscles, tendons, ligaments, cartilage, etc.) will benefit greatly from this influx of blood.

Systolic blood pressures of 350-400 mmHg have been measured during very heavy lifting, i.e. 90-100+% of a 1RM back squat. A systolic blood pressure of 120 mmHg is normal for most people at rest. You can see the difference between the readings at rest and during the middle of a heavy rep is enormous. Obviously, the larger reading is transient in nature, meaning it peaks and then rapidly decreases as the athlete finishes the rep and racks the bar.

Obvious statement here: make sure your cardiovascular (CV) system is ready for this extra influx and increased tension. If there are any weaknesses along the CV pathway, make sure you get it checked out and fixed, before proceeding.

Not so obvious statement here: be patient with developing your ability to increase your tension and your body’s ability to manage the perfusion effect. Not doing this could create an injury or any number of CV events. Slow but sure is the way to go when it comes to training, especially in the beginning.

The Scientific Mumbo Jumbo of Perfusion

As our society has become less and less active and our work labor has gone from the fields and factories to the desk and handheld devices, we are becoming more unfit every day. Dr. James Levine and Gray Cook have said many times that “sitting is the new smoking.” With this increasing lack of movement and exercise, serious diseases such as cancer, heart disease, and type 2 diabetes are on the rise.

We know that movement and exercise are important for bettering our health, increasing our longevity, and improving our overall health. Several studies demonstrate this on a more cellular level.

Thijssen et al.’s review of the current evidence found that chronic increases in blood pressure—typically the result of stress, lots of it, coupled with lack of exercise and poor diet—result in a thicker carotid arterial wall. Not good. On the flip side, while performing exercise increases blood pressure as well, it leads to a larger stretch on the arterial wall during that exercise. This in turn is associated with a lower arterial wall thickness. Therefore, changes in arterial wall thickness can be different depending on whether the increase in blood pressure is due to a chronic elevation (i.e. stress, etc.) or the transient, episodic, and cyclical increases in blood pressure that occur in response to exercise.2

As discussed above, capillaries are the smallest blood vessels in the human body. They are responsible for transporting nutrients and wastes to and from your body’s tissues. It has been shown that exercise increases the density of the capillaries present, improves their function, helps prevent age-related capillary function decline, and can help with the development of new capillaries.

Spence et al. found that resistance training (using the bench press and squat as measurements) not only decreased the wall thickness in the brachial, femoral, and carotid arteries (a good thing), but also increased the diameter in two of the aforementioned vessels with the femoral artery essentially staying the same.3

Whew! I need a rest now after researching and reading all of the above and the associated studies!

Alright, what does all of this mean for those of us training with resistance?

The How of Perfusion and Its Mechanics

When we exercise, whether aerobic or strength-based training, our pulse and respiration rate and blood pressure increase. In the case of strength training, especially heavy strength training, it has been found that the momentary increases of the systolic pressure can be quite high, upwards around 350-400 mmHg. This increase in pressure helps push large amounts of blood to the smallest blood vessels we have—the capillaries. This, in turn, infuses the tissues associated with these tiny vessels with loads of nutrients and helps remove large quantities of waste products.

If the blood pressure was lower, as it remains in aerobic training, this large infusion of blood—perfusion—would not occur as greatly. During aerobic training, a greater amount of perfusion than that of a sedentary situation would still occur, but the increased tension and pressure generated with heavy strength training wins hands down.

Perfusion also helps keep the elasticity of the blood vessels strong. As I like to say to my patients, the body subscribes to the law of “use it or lose it.” If you don’t allow the blood vessels to get stretched by exercise on a regular basis, they will lose that ability. Someday you will require them to stretch in a large, unexpected way. They will not be used to it and a potential cardiovascular event can occur—i.e. you can have a heart attack.

So, in a nutshell, make sure your body can handle the increased blood pressure safely and lift heavy, often. With proper programming and excellent technique, your skin will thank you. The rest of your body and your wallet from not having to buy skin products will also.