The Ultimate Guide to Exercise and Metabolic Health

By Greg Presto

When you’re walking, thinking, talking, running — even just reading this sentence — your body is using fuel to keep you going. Your metabolism makes sure you don’t run out of gas.

Metabolism describes how your body uses different substances — mostly fats and carbohydrates — and a dizzying number of steps to convert those substances to energy for your cells. And while you may think of exercise as burning energy, it actually helps the energy-converting pathways work better.

“With exercise, the pathways are working together in a more efficient way,” says Matthew Laye, Ph.D., associate professor at the Idaho College of Osteopathic Medicine. The different processes by which your cells turn fats and carbs into energy are more seamless in the short- and long-term. So your metabolism runs more smoothly, Laye says.

That smooth, efficient machinery is a sign of good metabolic health. And that’s huge: Metabolic health is the foundation of overall wellbeing, impacting not just your energy throughout the day, but also your mood, memory, sexual health, immune system functioning, and your ability to fight off chronic diseases like heart disease, diabetes, and cancer.

Exercise makes it all work better. Here’s how, and how you can start unlocking the power of sweat to improve your body’s energy-making machinery.

How Exercise Impacts Metabolic Health Markers

Your metabolic health is defined by the levels of five markers: fasting triglycerides, fasting high-density lipoprotein (HDL) cholesterol, waist circumference, blood pressure, and fasting blood sugar. When this quintet of measurements is in optimal ranges without medication, you’re said to be “metabolically healthy”—all your metabolic systems are working smoothly to make energy for your cells.

When three of the five markers are all in the danger zone, it’s called “metabolic syndrome,” a condition associated with an increased risk of cardiovascular disease, including a two- to four-fold increase in the risk of stroke and tripled risk for heart attack. People with metabolic syndrome are also at an elevated risk for diabetes.

Exercise helps improve all five markers of metabolic health:

Triglycerides:

• What they are: The most common type of fat in your body. When you eat excess calories, your body stores them as triglycerides.

• How they impact health: Elevated levels of triglycerides in your blood — above 150 mg/dL — are associated with increased risk of cardiovascular disease. In some populations, the risk is worse when high triglycerides are paired with low HDL cholesterol. In women over 65, for example, one study found that this pair of risk factors more than tripled the risk of cardiovascular disease. Elevated triglycerides are also tied to insulin resistance, the condition underlying Type 2 diabetes.

• Impact of exercise: Studies have found that people who are more active have lower triglyceride levels. Resistance training has been shown to lower these levels, and higher-intensity cardio activities were found in a 2013 study to provide more benefits than moderate-intensity cardio.

High Density Lipoprotein (HDL):

• What it is: Although there are still questions about HDL’s role in cardiovascular disease risk, it’s generally considered beneficial, in part because it sweeps up the cholesterol in LDL particles in the bloodstream and carries it away. This helps keep LDL from building up along the artery walls, leading to clots that can cause heart attack.

• How it impacts health: Low levels of HDL — often defined as less than 40 mg/dL in men and 50 mg/dL in women — are associated in studies with increased risks of death from for cardiovascular disease.

• Impact of exercise: Exercise improves the amount of HDL in the blood both in the short- and long-term, and recent evidence suggests that exercise may make HDL more efficient.

Waist Circumference:

• What it is: A measurement of the waist, taken just above the hip bones. A circumference greater than 40 inches for men or 35 inches for women is a risk factor for cardiovascular disease and diabetes.

• How it impacts health: A larger waist circumference indicates storage of visceral fat—a deep, hard type of fat that’s more commonly associated with disease risk than subcutaneous fat, which is closer to the surface of the skin. Visceral fat contributes to insulin resistance, a condition where insulin can’t do its job clearing blood sugar (increasing the risk for diabetes). It is also related to increased risks for certain types of cancer and Alzheimer’s — inflammatory chemicals released by this type of fat may contribute to the disease.

• Impact of exercise: Losing weight reduces weight circumference, but exercise specifically helps. In a year-long study of more than 600 people, those who lost weight while following an exercise program, eating an “energy-restricted Mediterranean diet,” and attending dietary education saw greater reductions in waist circumference than those who lost weight with dietary education alone.

Blood Pressure:

• What it is: The force of your blood pressing against the walls of your arteries as it flows through them. Blood pressure consists of two numbers: The systolic pressure (top number) is a measurement of the force exerted on your arterial walls when your heart beats. The “bottom number” is diastolic pressure, which is the pressure your blood exerts between beats.

• How it impacts health: When someone has systolic pressure over 130 mmHg and/or diastolic pressure over 80 mmHg, they have hypertension, or high blood pressure. People with hypertension are at increased risk for heart attack, stroke, and death.

• Impact of exercise: Regular exercise lowers both blood pressure numbers: A review of 27 studies found that regular medium- to high-intensity aerobic exercise reduced systolic pressure by an average of 11 mmHg and diastolic pressure by an average of 5 mmHg.

Fasting Blood Sugar:

• What it is: A measure of how much glucose is circulating in the blood at rest.

• How it impacts health: Chronically elevated blood glucose can lead to insulin resistance, a condition where your cells stop responding to the insulin that’s secreted by your pancreas, signaling them to process glucose. When your resting blood glucose is chronically high, or you have frequent severe flucutations, you’re at an elevated risk for diabetes.

• Impact of exercise: Exercise has been associated with better glucose control. See the next section for more.

Read the full article on Levels.

Originally published July 28, 2023.