It might be tempting for those diagnosed with cancer to rest in excess. However, emerging research—and an 80-year-old doctor who completed the Boston Marathon—suggest that’s the wrong advice.
Dr. Michael F. Holick was an active, working 75-year-old when he was diagnosed with Stage 3 prostate cancer in December 2021. He felt overwhelmed when he heard that his treatment would leave him feeling physically and mentally depleted.
“Once you get this diagnosis, it stops you in your tracks; the whole world just stops,” Holick told The Epoch Times. “And you have to rethink your life.”
As a researcher and a medical doctor who’s seen more than 25,000 patients with bone diseases, Holick repeatedly told patients to exercise more. He especially lectured one subset of at-risk patients: those with prostate and breast cancer who took hormonal treatments that deprive them of bone- and muscle-protective estrogen and testosterone.
Once Holick’s role reversed, he realized how challenging his advice was, yet he also realized how vital it was. Patients might desire the improved energy, strength, and mood that exercise can bring but be too fatigued to reach for the antidote.
Holick admitted that it took a dogged determination to intensify his existing weight-lifting workouts, add long daily walks, and eventually run-walk the Boston Marathon. However, his strategy can help others battling cancer.
Weight Lifting Raises Energy
Weight lifting when one has cancer becomes less about bulking up and more about gaining control over energy and preventing the slippery slope of bone and muscle loss.
This is especially important for men with prostate cancer who have surgical removal of the testicles or receive androgen deprivation therapy, as both drastically lower testosterone levels, and for women with estrogen-receptor-positive breast cancer who often take drugs that lower estrogen levels. Low testosterone lowers physical strength and leads to exercise intolerance; low estrogen affects sleep and energy and leads to fatigue.
In both cases, patients are at risk of osteoporosis and higher fracture risk and may struggle with side effects such as hot flashes, fatigue, muscle weakness, and weight gain, further challenging their motivation to exercise.
Holick noted that his twice-a-week weight-lifting workouts became far more difficult once he started androgen deprivation therapy that lowers testosterone to block it from fueling cancer cells. Stress—including the moderate but short-term spike in cortisol, adrenaline, and heart rate—can exacerbate hot flashes.
“I was getting up to 20 a day,” he said. “It exhausts you instantly, and you basically can’t function.”
He kept lifting anyway, and today he’s moving heavier weights than he was before his diagnosis. The difference is his attitude, he said. He’s become disciplined about putting in maximum effort during sessions.
Don’t expect to see a body transformation, such as weight loss or a smaller waist circumference, according to the results of a study of 155 men with prostate cancer published in the Journal of Clinical Oncology. However, after 82 of the men completed a 12-week program on resistance machines for upper- and lower-body strength, they had results where it mattered: less fatigue, greater ability to complete daily tasks, and feeling more capable and independent than the men who did nothing.
Walking May Shrink Tumors
Moderate exercise seems to be optimal—too little or too much minimizes benefits. It’s a concept similar to hormesis, which holds that a small amount of stress strengthens the body, while too much can backfire.
In a study of 53 men with prostate cancer, less than three hours and 45 minutes of exercise weekly on a treadmill had little effect on tumors, and neither did seven and a half hours of weekly exercise.
The sweet spot for slower-growing cancer cells was three hours and 45 minutes to six hours and 15 minutes of weekly exercise, according to the results published in JAMA Oncology. The American Cancer Society recommends that adults get 150 minutes to 300 minutes of moderate-intensity or 75 minutes to 150 minutes of high-intensity aerobic activity each week, stating that it’s ideal to hit or exceed the upper limit of 300 minutes. Meanwhile, it recommends limiting sedentary behavior, including sitting, lying down, and watching television or other screens.
Holick, who played tennis and gardened before his cancer diagnosis, said he intuitively knew he needed more consistent, intentional activity. He settled on walking a minimum of five miles every day before radiation treatment.
“I was absolutely committed,” he said. “I did it every day, whether it was snowing, sleeting, or raining outside.”
Running With Walking: Better for Muscles
Once Holick finished radiation therapy, he made a surprising decision: to complete the Boston Marathon, despite never having run before. To prevent muscle wasting, a common problem among runners, he adopted U.S. Olympian Jeff Galloway’s run-walk-run method.
A form of interval training, the method eases the intensity and load on the muscles during running, reducing stress and fatigue. One study published in the Journal of Science and Medicine in Sport found that alternating running and walking is a good approach for novice runners.
Participants assigned to the run-walk strategy reported less muscle pain and fatigue than those who ran continuously—and they achieved similar finish times.
Holick, who plans to complete his third Boston Marathon this year, said that as difficult long-distance running is, recovery takes only a couple of days—something he credits to the run-walk-run method.
“Runner’s high is very real,” he said. “I was absolutely thrilled at the end of both marathons … in seventh heaven.”
Most Cancers Benefit From Moderate Movement
Although the task might seem daunting, exercise for cancer patients is a literal lifeline; it’s tied to better survival rates across a range of diagnoses.
An analysis published in the Journal of the National Cancer Institute found that moderate-to-vigorous physical activity appears to improve survival across 10 cancer types: prostate, breast, colon, bladder, endometrial, kidney, lung, oral, rectal, and respiratory cancer.
“Finding an exercise that you enjoy or exercising with a friend can make it more approachable,” Erika Rees-Punia, senior principal scientist at the American Cancer Society and lead author of the study, said in a news release.
Holick began sharing his cancer and exercise journey on social media, hoping to encourage others to take their doctors’ advice. He holds nothing back: Besides cancer, he was diagnosed with Type 2 diabetes, which he reversed by changing what he eats. He also has anemia, a common problem among those with low testosterone that reduces oxygen levels throughout the body. Despite the aggressive form of his cancer, Holick remains in remission.
“It’s an impediment, but none of that was going to stop me,” he said. “I try to explain to people that it shouldn’t stop you either. You just got to do it.”