It is well known that regular physical exercise has a plethora of associated health benefits and has been shown to prevent and improve symptoms across all types of diseases, but are the current guidelines too challenging for the average person? We investigate.
Exercise has been hailed as somewhat of a miracle cure. It is free, easy to do, works immediately, and has little to no side effects. Scientific evidence has shown that, whatever your age, being physically active makes you happier and healthier.
The United States Department of Health and Human Services (HHS) 2008 Physical Guidelines for Americans report that for adults, the most substantial health benefits occur with at least 150 minutes (2 hours and 30 minutes) per week of moderate-intensity aerobic physical activity, or 75 minutes (1 hour and 15 minutes) each week of vigorous-intensity aerobic physical activity.
Muscle strengthening (otherwise known as resistance training) physical activities that involve all the main muscle groups and that are moderate or high intensity should also be completed on 2 or more days every week.
The 2008 Physical Guidelines for Americans document that taking part in the equivalent of 150 minutes of moderate-intensity aerobic activity each week lowers the risk of:
Stepping up physical activity from 150 minutes each week toward 300 minutes (5 hours) not only further lowers the risk of heart disease and diabetes, but also reduces the risk of colon cancer and breast cancer, and prevents unhealthy weight gain.
Moreover, increasing physical activity to more than the equivalent of 300 minutes per week of moderate-intensity aerobic physical activity further increases the benefits. For example, people who complete 420 minutes (7 hours) each week have an even lower risk of premature death, compared with individuals completing 150 to 300 minutes every week.
There are multiple ways to meet the recommended 150 minutes of exercise. In fact, research conducted by the University of California, Los Angeles Medical Center and the University of Pittsburgh showed that participating in a variety of activities - from walking and dancing, to gardening - improves brain volume and may reduce a person's risk of developing Alzheimer's disease by 50 percent.
Under 25 percent of adults meet guidelines
It sounds easy enough: by working out for 30 minutes on 5 days of the week, those recommendations can be met. You would expect that with all the potential health benefits, the whole population would be following the recommendations and taking to the streets to walk briskly.
However, a huge proportion of the population is falling short. According to the Centers for Disease Control and Prevention (CDC), around 49 percent of adults meet the aerobic physical activity guidelines, and only 20.9 percent of adults meet the physical activity guidelines for both aerobic and muscle-strengthening activity.
So what is going wrong? With our busy lives, 30 minutes of moderate physical activity can be a challenging task to fulfill and may even be regarded, by some, as impractical or unobtainable.
Many of us claim that we do not have the time, energy, or inclination to fit in exercise. So not only are the guidelines and long-term health benefits failing to engage the population, but they are also being dismissed and ignored, and they even appear to be discouraging individuals to participate in any physical activity at all.
The HHS guidelines were released nearly 10 years ago, and in that time there has been considerable research into physical activity duration, frequency, and intensity. Do we really need to accumulate 150 minutes of physical activity every week? We take a look at some of the most recent findings.
Health benefits from less than the recommended amount of exercise
The good news is that some health benefits can be gained with as little as 60 minutes of moderate-intensity activity each week, and some research has shown positive results with even less exercise.
One moderate exercise session of 20 minutes stimulates the immune system and sets off a cellular response that may help to suppress inflammation in the body, found a study published in Brain, Behavior, and Immunity.
"Our study shows a workout session doesn't actually have to be intense to have anti-inflammatory effects. Twenty minutes to half an hour of moderate exercise, including fast walking, appears to be sufficient," said Suzi Hong, Ph.D., in the Department of Psychiatry and the Department of Family Medicine and Public Health at the University of California, San Diego School of Medicine.
"Feeling like a workout needs to be at a peak exertion level for a long duration can intimidate those who suffer from chronic inflammatory diseases and could greatly benefit from physical activity."
Research involving more than 7,000 participants found that doing under 1 hour of resistance training per week was linked with a 29 percent lower risk of developing metabolic syndrome. This condition is a cluster of risk factors that increase the likelihood of developing cardiovascular diseases such as heart disease, stroke, and type 2 diabetes.
"Few studies have reported on the health effects of resistance exercise, and this is the first such study concerning metabolic syndrome," explained Esmée Bakker, from the Radboud University in Nijmegen, in the Netherlands.
"Our results indicate that a modest amount of resistance exercise, such as two 30-minute sessions per week, has the most beneficial effect. These findings should be included in the standard medical recommendations for preventing metabolic syndrome and future cardiovascular disease."
Another study published in the journal Medicine & Science in Sports & Exercise suggests that for children with large waist measurements and elevated blood insulin levels, 10 minutes each day of high-intensity physical activity could cut their risk of developing heart problems and metabolic disease.
A review exploring the effects of acute exercise found that a single bout of physical activity improved executive brain function, enhanced mood, and decreased stress levels. What is more, neurophysiological and neurochemical changes were observed that indicated the widespread activation of brain areas and brain systems.
"The studies presented in this review clearly demonstrate that acute exercise has profound effects on brain chemistry and physiology, which has important implications for cognitive enhancements in healthy populations and symptom remediation in clinical populations," commented Julia C. Basso, Ph.D., postdoctoral research fellow at the Center for Neural Science at New York University in New York City.
The University of British Columbia (UBC) in Okanagan, Canada, investigated whether physical activity improves body image.
Women who were assigned to complete one 30-minute session of moderate-to-vigorous exercise significantly improved their body image perception compared with women who engaged in quiet reading.
"We all have those days when we don't feel great about our bodies," said Kathleen Martin Ginis, a professor in UBC Okanagan's School of Health and Exercise Sciences. "This study and our previous research shows one way to feel better, is to get going and exercise. The effects can be immediate."
Investigators at the Hospital for Special Surgery (HSS) in New York City, NY, found that low-impact exercise helped to decrease pain, improve mobility, and enhance the quality of life for older adults.
"The study results are consistent with the experience of rheumatologists and with prior studies showing that exercise, even of mild degree, helps with pain," noted Dr. Theodore Fields, director of the Rheumatology Faculty Practice Plan at HSS. "Getting people up and moving does appear to help with mood, pain, and overall functioning."
"Joints will often stiffen if not used, and muscles will weaken if not exercised. Our bodies are meant to move, and inactivity leads to weakness and stiffness, and joints with arthritis often worsen with inactivity."
Just 6 months of participating in moderate-intensity continuous training (MICT) for 30 minutes on 3 to 4 days per week improves sperm quality significantly.
Research published in Reproduction revealed that compared with a control group that did no exercise, individuals in the MICT group had 8.3 percent more semen volume, 12.4 percent higher sperm motility, 17.1 percent improved sperm cell shape, 14.1 more concentrated sperm, and 21.8 more sperm cells on average.
"Our results show that doing exercise can be a simple, cheap, and effective strategy for improving sperm quality in sedentary men," explained Behzad Hajizadeh Maleki, lead author of the study. "However, it's important to acknowledge that the reason some men can't have children isn't just based on their sperm count. Male infertility problems can be complex, and changing lifestyles might not solve these cases easily."
A report released by the American College of Cardiology (ACC) Sports and Exercise Cardiology Council suggested that moderate- and vigorous-intensity physical activity in amounts lower than the physical activity guidelines can still significantly lower the risk of cardiovascular disease.
But Dr. Michael Scott Emery, co-chair of the ACC Sports and Exercise Cardiology Council, and colleagues point out that more exercise results in an even greater reduction of risk of death from cardiovascular disease.
"The available evidence should prompt clinicians to recommend strongly low and moderate exercise training for the majority of our patients," Dr. Emery said. "Equally important are initiatives to promote population health at large through physical activity across the lifespan, as it modulates behavior from childhood into adult life."
Researchers at the University of Connecticut (UConn) in Mansfield have discovered that there is no need to spend hours at the gym to feel good about yourself. The team compared people who took part in light-, moderate-, and vigorous-intensity exercise with those who were inactive.
They found that individuals who participated in light-intensity physical activity reported higher levels of psychological well-being and lower levels of depression, whereas people who engaged in moderate-intensity physical activity reported higher psychological well-being levels and lower levels of pain.
"We hope this research helps people realize the important public health message that simply going from doing no physical activity to performing some physical activity can improve their subjective well-being," clarified Gregory Panza, a graduate student in UConn's Department of Kinesiology and the study's lead author.
"What is even more promising for the physically inactive person is that they do not need to exercise vigorously to see these improvements. Instead, our results indicate you will get the best 'bang for your buck' with light- or moderate-intensity physical activity."
The physical activity guidelines suggest that children participate in 60 minutes or more per day of moderate- or vigorous-intensity exercise.
However, research by Johns Hopkins Bloomberg School of Public Health in Baltimore, MD, found that if all children aged 8 to 11 years took part in just 25 minutes of exercise 3 times per week, then $62.3 billion in lost wages and medical costs could be avoided, not to mention the fact that 1.2 million fewer children would be overweight or obese.
"As the prevalence of childhood obesity grows, so will the value of increasing physical activity," said study leader Dr. Bruce Y. Lee, executive director of the Global Obesity Prevention Center at the Bloomberg School of Public Health. "We need to be adding physical education programs and not cutting them. We need to encourage kids to be active, to reduce screen time and get them running around again. It's important for their physical health - and the nation's financial health."
Research presented at the EuroPrevent 2016 meeting by Dr. David Hupin - a physician in the Department of Clinical and Exercise Physiology at the University Hospital of Saint-Etienne in France - found that just 15 minutes of physical activity each day is associated with a 22 percent decreased risk of death.
"We found that the low level of activity, which is half the recommended amount, was associated with a 22 percent reduced risk of death in older adults compared with those who were inactive," said Dr. Hupin. "This level of activity equates to a 15-minute brisk walk each day."
"We think that older adults should progressively increase physical activity in their daily lives rather than dramatically changing their habits to meet recommendations. Fifteen minutes a day could be a reasonable target for older adults. Small increases in physical activity may enable some older adults to incorporate more moderate activity and get closer to the recommended 150 minutes per week," Dr. Hupin concluded.
While recent research of lower physical activity levels is promising for those of us with little spare time, research that explores exercise at the recommended levels or higher is even more illuminating. However, that will have to wait for another day.
The bottom line is that any activity is better than no activity. While the recommended physical activity levels may be difficult for some people to achieve, doing any amount of exercise provides health benefits and is significantly better for health than being inactive.
Exercise does not have to be a grueling uphill struggle; it can take place in short bursts and be fun. Make a difference to your health by getting off the couch and moving!