Kimbers Cadieux never particularly enjoyed working out — "if left to my own devices, I wouldn't do it," she said. But the 64-year-old cancer survivor is exercising almost daily now to reduce her odds of complications if she's ever infected with the coronavirus that causes COVID-19.

"If COVID shows up, I want to be stronger," she said.

Cadieux's conversion to a daily fitness regimen matches the latest guidance from health experts, given data showing that more than nine in 10 COVID-19 deaths in Minnesota involved people who were senior citizens or who were younger but with underlying health conditions such as obesity or diabetes.

Led by Dr. William Roberts of the University of Minnesota, the American College of Sports Medicine (ACSM) issued guidance Friday advising 150 to 300 minutes of moderate to vigorous exercise each week to reduce risks of severe COVID-19.

"It doesn't have to be 150 to 300," Roberts said. "If you can only get in 30 minutes a week or 60 minutes, it's better than none. The biggest thing ... is to get off the couch."

COVID-19 has disrupted many exercise regimens, particularly during the 51-day statewide lockdown this spring and the closure of fitness clubs that ended June 10. Health officials urged people to find new routines amid the pandemic, which as of Tuesday had caused a cumulative 61,839 known infections, 5,661 hospitalizations and 1,666 deaths in Minnesota.

The tally included six deaths reported Tuesday and 332 newly lab-confirmed cases. The state reported that 337 Minnesotans with COVID-19 were hospitalized on Tuesday, including 147 patients who needed intensive care.

State health officials have focused their public health messaging on the need for social distancing and mask-wearing to reduce transmission of the SARS-CoV-2 coronavirus, but they agreed with the new fitness guidelines.

"Obesity is a risk factor for more severe outcomes with COVID," said Kris Ehresmann, state infectious disease director. "We have really been providing a lot of guidance related to preventing COVID that's very much in the moment and short term, if you will. So wear a mask, socially distance, all of those things, but there are many other things we can do to make sure we are staying healthy."

Obesity is one of eight conditions listed by the U.S. Centers for Disease Control and Prevention as carrying an elevated risk for severe COVID-19 and is common among Minnesotans hospitalized with the disease.

Among a sampling of 867 Minnesotans aged 18 to 49 who were hospitalized for COVID-19, 51% had an underlying health condition and 28% were obese, according to state hospital data.

Cadieux had gained weight as part of her recommended diet amid treatments for uterine cancer and signed up in the winter for Life Time fitness' new club in Edina. She said her motivation to use the gym came with reports of elevated risks of severe COVID-19 for people with cancer and obesity.

Three times a week, a trainer helps Cadieux with weightlifting and resistance training, and twice a week she rides a bike at the club or does other cardiovascular exercise.

The ACSM guidance recommends exercise at home or outdoors to reduce virus transmission risks, but Cadieux said her allergies to grass and pollens make it difficult. Her workout routine didn't start in earnest until the state allowed the limited reopening of fitness clubs in June, and her trainer helped her develop a plan.

Although she hasn't lost much weight, she said it has shifted from fat to muscle much quicker than she imagined.

"My sister was just here, and she was like, 'Oh my God, look at your guns.' I just about fell over," she said.

The ACSM guidance calls for mask-wearing during exercise if necessary to prevent contact with droplets from others who are speaking, coughing or breathing nearby.

Roberts said he was biking recently and closing in on another rider who turned and spit in his direction.

"One of the rules [to reduce transmission] is don't spit, which is an incredibly difficult habit to break," he said. "We're trying to encourage the baseball guys not to spit."

The ACSM guidance does point to risks of overdoing exercise.

Moderate to vigorous activity is ideal, but extreme workouts can cause exhaustion and leave people vulnerable to viral infection.

Roberts, who also is the medical director of the Twin Cities Marathon, said this isn't the best time "to start doing speed work or hill work." Extreme athletes should consider isolating themselves from exposure risks in the day or two after a hard workout.

"The immune system appears to be a bit suppressed for a period of time — an hour, a day — following really exhausting exercise," Roberts said. "I don't think we really know the full mechanism behind it, but we do know it does increase your risk of viral illness."

The guidance also urges consultation with a physician before people with COVID-19 resume exercise, because of lingering damage the disease can have on the lungs.

Until science-based guidance is proven, the organization advised people to rest and refrain from exercise for two weeks after mild to moderate COVID-19 symptoms and then to gradually return to prior levels of activity.