Physical Inactivity a Top Predictor of Severe COVID-19 Outcomes

We review three studies that show a link between physical inactivity and odds of more severe COVID-19 outcomes, the potential benefits of resistance training for people with rheumatoid arthritis, and Pilates’ efficacy as a fall risk prevention strategy.

The Health Benefits of Exercise Report is a newsletter and article series in which we select three peer-reviewed articles, summarize the key findings, and provide social media images for you to share with your community. You can read previous articles here.

The COVID-19 pandemic may show signs of improvement in some areas, but maintaining a physically active lifestyle continues to present a challenge. We know that exercise is a key measure to maintaining good physical and mental health and well-being. This month’s edition of the Health Benefits of Exercise Report covers:

  1. A study finding higher odds of COVID-19 hospitalization, ICU admission, and death among consistently inactive compared to active people,
  2. A systematic review and meta-analysis of the effects of resistance training in people with rheumatoid arthritis, and
  3. A study showing that mat Pilates was more effective than general physical activity programs for fall prevention, though both were beneficial.
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Physical Inactivity a Top Risk Factor for Severe COVID-19 Outcomes

Physical activity has numerous health benefits, including:

  • cardiovascular and metabolic health,
  • lung capacity,
  • muscle strength, and
  • immune system health.

Physical inactivity is a risk factor for several chronic health conditions that also elevate the risk for more severe COVID-19. Some previous evidence suggests a link between physical inactivity and higher odds of more severe COVID-19 outcomes. A new study published in the British Journal of Sports Medicine found similar results.

The study analyzed data on 48,440 Kaiser Permanente Southern California patients who had tested positive for COVID-19 between January and October 2020 and who had at least three Exercise Vital Sign measurements in the two years preceding the pandemic. Exercise Vital Sign is a measurement of physical activity included in a patient’s health records at Kaiser Permanente Southern California since 2009. The vital sign consists of a patient's weekly frequency and duration of moderate to strenuous exercise. Based on vital sign measurements, 6.4% of patients in the study were consistently active, 14.4% were consistently inactive, and the remaining 79.2% were inconsistently active. The participants analyzed had an average age of 47, a mean body mass index of 31.2 (which falls under the class I obesity range), and just under half had one (17.4%) or two or more (31.3%) comorbidities.

According to the findings, there is a strong association between physical inactivity and COVID-19 outcomes, and physical activity provided significant protection from more severe outcomes, including:

  • hospitalization,
  • ICU admission, and
  • death.

Being consistently inactive more than doubled the odds of hospitalization and death compared to being consistently active. The odds of ICU admission were 1.73 times higher. Even being less consistently active was associated with benefits, including 20% lower odds of death.

The key finding is that—aside from being over age 60 and having a history of a solid organ transplant—consistent physical inactivity was the most significant risk factor for COVID-19 death. These results would point to physical inactivity as the most significant modifiable risk factor for COVID-19 severity. Physical inactivity is a risk factor that almost anyone can improve in a shorter timeline—and can be more accessible than other risk factors such as weight loss. Considering the accessibility and importance of physical activity for physical and mental health, physical activity should be a priority in the ensuing months of recovery and reopening.

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Resistance Training Can Benefit Rheumatoid Arthritis Sufferers

In addition to medication, exercise is an important part of rheumatoid arthritis (RA) management. Aerobic activity can also lower cardiovascular risk, which can impact RA outcomes. Research shows aerobic training has improved cardiovascular fitness and quality of life and reduced pain and disability in people with RA. The evidence is less conclusive when it comes to resistance training. A systematic review and meta-analysis, published in Medicine, aims to determine the effect of resistance training on:

  • pain,
  • disease activity,
  • functional capacity,
  • quality of life, and
  • structural damage in people with RA.

The study also looks to determine if adding resistance training to treatment is clinically beneficial.

The review included 17 randomized controlled trials involving 1,010 participants—512 who participated in resistance training and 498 controls. According to the findings, resistance training:

  • Reduced disease activity,
  • Reduced ESR—a measure of inflammation—and
  • Improved patients’ 50-foot walk test score.

Other similar studies have found resistance training improved grip strength, slowed disease progression, improved joint function, alleviated pain, and improved joint stiffness. Higher quality and more extensive research studies are still needed, and the authors recommend future studies look at exercise frequency and intensity.

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Pilates Improves Balance, Strength in Older Adults

Physical activity exerts several key benefits in older age, including:

  • muscle strength,
  • balance,
  • postural control, and
  • improved recovery following injury.

Evidence suggests physical activity can be an effective fall prevention strategy, but it is not clear as to which specific type of activity is most effective. A study published in the journal Medicine compared a regular physical activity program to a pilates program in 41 previously non-exercising adults over age 55. Both programs ran for 13 weeks. The physical activity group did equipment-free aerobic and stretching exercise, accumulating 160 minutes of aerobic activity. The Pilates group did mat-based exercises for 50 minutes, three times a week. An exercise specialist supervised the sessions.

The study findings aligned with existing evidence, showing that a physical activity program improved balance and had a positive effect on fall prevention. In this study, Pilates was more effective compared to the general physical activity program. The authors conclude that their results “suggest that Pilates could be considered for stabilization training and to reduce the risk of falls in the elderly.”

This study used mat Pilates, which requires little equipment and is an exercise that traditional fitness studios can offer. Given the efficacy of both the general physical activity program and Pilates in this study and the importance of strength and balance, fitness centers can play a key role in fall prevention efforts.

Related Articles & Publications

  • Physical Activity During COVID-19 Linked to Mood

  • Higher Activity Tied to Lower Risk of Cardiovascular Events

  • Resistance Exercise Lowers Anxiety Symptoms in Young Adults

Author avatar

Alexandra Black Larcom

Alexandra Black Larcom, MPH, RD, LDN, previously served as IHRSA's Senior Manager of Health Promotion & Health Policy—a position dedicated to creating resources and projects to help IHRSA members offer effective health programs, and promoting policies that advance the industry.