The Profound Impact of Walking on Metabolism

Source: Olga Danylenko/Shutterstock

By Mac E. Lancaster, BS, and Ran D. Anbar, MD

Approximately 1 in 10 Americans have diabetes, and the vast majority of them have type-2 diabetes mellitus (T2DM) (Centers for Disease Control and Prevention). T2DM has increased dramatically since the 1990s (Klonoff, 2009; Liu et al, 2020). The trend in rates of diabetes is due to myriad elements including changes made to the diagnostic criteria (Selvin & Ali, 2017). Additionally, risk factors for T2DM such as obesity, poor diet, and lack of physical activity have emerged at a growing rate in children and adolescents (Ismail et al., 2021).

As creatures of psychology, we also have a duty to understand our physiology. How we treat our bodies affects the operation of our minds. T2DM is associated with forms of cognitive impairment that affect planning and decision-making (Luchsinger, 2018). Metabolic disorders typically co-occur and exacerbate cognitive decline as fat and cholesterol turn into plaque that builds up in arteries in the brain (Marseglia, 2021).

We can combat the prevalence of metabolic disorders in society by structuring our lives to positively impact our “healthspan"—the number of years lived without a disease (Garmany et al., 2021). For example, we can take walks to decrease negative emotions and promote metabolic balance (Sharma et al., 2006). But to understand the process of metabolism, one must first understand insulin.

Insulin and Insulin Resistance

Insulin is a hormone released in response to glucose (a sugar from the carbohydrates we eat) entering the bloodstream (Vargas et al, 2023). The metabolic process involving insulin occurs as follows:

• Carbohydrates are ingested and broken down into glucose that enters our blood.
• Insulin is released from the pancreas in response to the elevation in blood sugar.
• Insulin activates the transporter-protein GLUT4 to store glucose in muscle, fat, or liver cells, where it can be used as an energy source.
• The pancreas stops releasing insulin after the blood sugar returns to normal.

It is important to distinguish that type-1 diabetes only occurs in 5-10 percent of patients and is marked by the pancreas’ inability to make insulin. (Centers for Disease Control and Prevention) Conversely, type-2 diabetes occurs as the body grows used to insulin being released and becomes resistant to it.

As a result of insulin resistance, the body cells of patients with T2DM do not have access to sufficient energy, and their blood sugar rises in an ineffective attempt to get glucose into the body’s cells. Over time, high blood sugar can cause the development of blindness, heart disease, cancer, dementia, kidney failure, and poor circulation which can lead to the necessity for amputations (Centers for Disease Control and Prevention).

Exercise

In a culture where the consumption of “junk foods” is pervasive (Liu et al., 2021), how are we supposed to combat their damaging metabolic effects? One solution is to simply take a walk.

Low-intensity forms of exercise such as walking and lightweight lifting are some of the best preventative measures to take against insulin resistance, as they can lower blood sugar levels even for people with T2DM (American Diabetes Association). Exercise involves the metabolic process in the following way:

• Aerobic and resistance exercise promotes GLUT4 activation, independent of insulin (Vargas et al, 2023).
• When GLUT4 is activated, the excess glucose in the bloodstream is absorbed into muscle cells.
• Muscle cells use glucose for energy, which allows you to continue exercising.
• Blood sugar levels drop after glucose is used by muscle cells as an energy source (Khan et al., 2019).

Walking can also help decrease obesity, which commonly occurs in patients with T2DM, and can help make the body more sensitive to insulin (Hamasaki, 2016; Khan et al., 2019).

A recent study analyzed the effects of walking for 30 minutes directly after a meal (Bellini et al, 2022). Walking post-meal was found to be particularly effective at lowering blood sugar, although it was least effective following the ingestion of a high-sugar beverage (Bellini et al, 2022).

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In addition to positively impacting physical health, studies have shown that adding walking to a daily routine can profoundly impact mental health by decreasing stress and promoting better sleep (An & Chuo, 2022). Walking has the demonstrated ability to decrease anxiety and depression by increasing blood circulation throughout the brain, especially in regions associated with mood (Sharma et al., 2006).

While walking can generally reduce negative emotions, it has been found that walking in an outdoor, natural setting leads to a significantly greater increase in positive feelings (Legrand et al., 2022). If you want the most out of your walk, take it in a natural setting.

Takeaway

Structure your life to work for you. The reality of metabolic dysfunction can be frightening, but you are the one in control.

If you know you crave sweets, set aside a time in the day when you can enjoy your favorite snack and schedule your exercise directly after that. If you know moderation works for you, don’t berate yourself when you have the occasional ice cream cone; understand this as an occasional treat, and that there are plenty of alternative foods that do not spike your blood sugar.

One of the authors of this blog (Ran Anbar) has elected not to own a car, which means that he has to walk 1.5 miles to and from work on a nearly daily basis. (This is made possible, in part, because he lives in temperate Southern California.) Thus, he has tailored a lifestyle of exercise into his normal routine that makes it easy for him to follow through on his intention to remain healthy.

The key is to use positive talk to achieve a lengthy healthspan, telling yourself that you are capable of following through with your intentions and achieving your goals. By incorporating metabolic awareness and exercise regimens such as post-meal walks into your routine, you can set yourself on a healthier path.