Exercise and Health: How Much Is Enough?

The American Cancer Society recommends that cancer patients aim for 150 minutes, or 2.5 hours, of physical activity a week. Broken down over seven days, this amount of time averages out to about twenty-two minutes a day. If you think about it this way, this is an incredibly doable goal. What’s even better is that those twenty-two minutes don’t have to be done at once.

In fact, research suggests that shorter bouts of exercise may have greater health benefits than longer endurance workouts. A 2016 study by Martin Gibala and his colleagues at McMaster University found that in previously sedentary individuals brief, but strenuous (10 minutes total, with only three 20 second episodes of flat-out exertion) exercise bouts three times a week for 12 weeks resulted in similar improvements in physiological and biological measures of fitness compared to those who exercised 45 minutes a week for twelve weeks.

It seems that benefits are also derived from bouts of intense exercise even as short as 4 seconds every hour! A study published last week by Edward Coyle and his team from the Human Performance Laboratory at University of Texas at Austin found that hourly 4 second bursts of maximal intensity cycle sprints interrupting prolonged sitting lowered the next day’s biological response to a high fat meal, decreasing markers of cardiovascular risk (triglyceride spike).

Previous research found the same effect for three 10-minute walks compared to a 30-minute walk in adults with borderline hypertension. The shorter walks had the same effect on blood pressure, but unlike the thirty-minute walk, they also reduced spikes in blood pressure, and so they had greater implications for overall health. We also know that simply sitting less and moving more is the ideal approach, as research suggests that:

  • walking more and sitting less is even healthier for you than exercising an hour a day if you are then sedentary for fourteen hours
  • replacing thirty minutes of sedentary time with light activity will reduce mortality risk
  • short bouts of activity will result in reduced inflammation and other hallmark biological factors driving cancer development

COVID-19 and Exercise

Exercise During a Pandemic

The extend time we are all spending at home due to SARS-CoV-2 virus and the ensuing COVID-19 illness is resulting in excess sitting and lack of exercise. However, this is a time to stand up and get moving as being in motion will improve all aspects of your health, boost your immune system, and create an environment that can better keep you virus free.

The human body, which is an evolutionary masterpiece of biological engineering, is designed to be in motion. Yet in large part, most of the hours of our lives are spent sitting. Recently, scientists have discovered that sitting is becoming a major health liability, and it is as detrimental to our health as smoking or eating poorly or any other number of less-than-healthy lifestyle choices that make us vulnerable to disease.

It is a well-accepted fact that exercise lowers your risk of cancer and other diseases such as heart disease, stroke, diabetes, and Alzheimer’s disease, as well as leading to increased quality and quantity of life. As we are all more or less isolated in our homes, how do we make it work for ourselves.

Making it Work for You

We believe that the best coach is our own body, so listen to your body and respond to its requests and needs. If you feel strong, balanced, flexible, and confident, you’re likely on the right track. Getting aerobic exercise (elevating your heart rate) on a regular basis is important, as is keeping your muscle strength up.

Break Up Your Day with Exercise Bursts

  • Use short workouts to break up your day. Three brisk 10-minute walks help to break up a long day of sitting.
  • If you like to run, a series of short sprints burns more calories than a long jog.

Break Up Your Sitting Time

Based on multiple studies, we encourage you to break up your sitting time by at least standing up:

  • Don’t do this once in a while, but hourly.
  • Standing will feel strange at first, but stick with it. As with most habits, after your body gets used to standing up, you will start to prefer this to sitting down to do work.
  • The ironing board is a great (and cheap) substitute for a standup desk at home and allows you to spread out your work.
  • Try standing when you watch television or shows on your computer.
  • Consider buying a lightweight laptop desk (which start at around $40) easily used at home, work, and even during travel.
  • Think about your children. School-age children need standup desks. They sit most of the day and then come home and sit for most of the evening— doing homework, playing video games, eating dinner, or watching TV.

Walk Instead of Sitting

  • Don’t do this occasionally, do this every day, at least once every one to two hours, even if you are merely walking around your house, around the block, or around the office.
  • Take the stairs at work, at the movie theater, at the airport, at doctors’ appointments— anytime you are going up or down, use the stairs.
  • Conduct walking meetings. Carry a clipboard to take notes. If someone at work wants to discuss an idea, suggest that you walk outside as you talk.
  • Park away from your destination and walk a few extra steps.
  • Walk to work, if possible, or bike.
  • Walk after dinner with those you care about— it allows you time to catch up and connect. Walking after a meal (especially a big meal) helps your body process food and could keep older people from developing diabetes.
  • Listen to a book on tape while you walk.

Develop a Fitness Routine

When you are ready for aerobic training and fitness, we suggest finding a friend to join you. For Alison, having a workout partner is an essential part of improving her fitness that helps keep her motivated and makes her responsible to someone other than herself.

Build your strength and your stamina. Resistance work is great for building muscle mass and protecting bone health. And your own body is your best source of resistance. A near perfect exercise is the simple plank. This activates your large muscle groups and builds arm strength. You can include free weights or resistance bands to create more tension on the muscles.

Start with something easily accessible that works with your schedule and temperament. Alison admires the runners who jog by our house every morning and evening, but she has no desire to be one of them. Be honest with yourself about what you want to do and what you can sustain. You don’t have to run a marathon. You just have to find a way to move more that works for you.

Exercise Improves the Health of our Microbiome


The ecosystem of bacteria, fungi, and viruses — living on and inside our bodies — is known as the microbiome. Even if you take baths daily, brush your teeth, and wash your hands, you are walking around accompanied by your own unique ecosphere of microbes, roughly a hundred trillion bacteria, some good, and some bad. In fact, our human cells are outnumbered ten to one by these nonhuman cells along for the ride. Mapping the microbiome, like the genome-mapping project, is an ongoing global effort. An unhealthy microbiome has now been linked with multiple diseases and conditions, including clostridium difficile infection, psoriasis, reflux esophagitis, obesity, childhood- onset asthma, gastrointestinal disorders, neuropsychiatric illness like depression and anxiety, multi-drug-resistant organisms, cardiovascular disease, and cancer.

A new study published by scientists from the University of Illinois at Urbana-Champaign found that exercise reliably modified aspects of the microbiome. The subjects, who had been previously sedentary, participated in supervised exercise three days a week for six weeks. They engaged in moderate to vigorous intensity exercise for 30-60 minutes each time. Importantly, they were asked to not change their diets. At the end of the six weeks the investigators found clear changes in the participants gut microbiome compared to before they started exercising. This was especially true for the normal weight individuals compared to those who were extremely overweight at the start. After only six weeks of exercise, the microbiome showed an increase in constituents reflective of decreased inflammation. The participants then reverted to their pre-exercise sedentary behavior for six weeks and their microbiome profile reverted back to the way it was prior to the study. These findings suggest that exercise can innervate the gut and modify the microbiome in a short period of time but sustaining these changes will require regular exercise.