Dr Parr Says…

Walking and running are widely used modes of exercise to improve fitness and promote weight loss. The energy expended (calories burned) during walking or running can be directly measured in a lab or estimated based on speed and body weight. It can also be determined using one of many wearable devices and mobile apps. A commonly used estimation is that walking or running one mile elicits an energy expenditure of 100 calories.

This estimation, while crude, is interesting because of its wide use and apparent acceptance, even though it hasn’t been tested for accuracy. Research we did in the Exercise Science Lab at USC Aiken and presented at the American College of Sports Medicine annual meeting last week examined the accuracy of the 100 calories per mile estimate across a wide range of walking and running speeds. This is the topic of my Health & Fitness column in the Aiken Standard this week

To do this we asked subjects ranging in age from 20 to 44 years to walk or run one mile at a speed they selected on a treadmill while energy expenditure was determined. Some of the subjects walked and some ran, so the speeds ranged from 3 to 7 mph. For accuracy, we measured the air they breathed to measure how much oxygen they consumed to calculate how many calories they burned.

We found that the measured energy expenditure across all speeds was 108 calories per mile. It was higher (115 calories) during running and lower (98 calories) during walking. None of these were significantly different from the 100 calories per mile estimate.

There was a high degree of variability among subjects in energy expenditure, even at similar walking or running speed. This was due to body weight, with heavier people burning more calories when they walked or ran.

These findings are consistent with previous studies that compared the measured energy expenditure of walking and running one mile at set speeds. In our study, we allowed subjects to select their own walking or running speed, so it more closely reflects how people would exercise outside of a research setting. Research also shows that the energy expenditure during treadmill exercise was almost exactly the same as walking or running on a track, so our findings would also be applicable to walking or running on level ground.

In conclusion, the widely used estimate of 100 calories per mile appears to be accurate across a wide range of walking and running speeds. This supports using the 100 calories per mile value for estimating energy expenditure for fitness or weight loss purposes. For example, some exercise programs prescribe exercise based on calories burned rather than time or distance. And people who are trying to lose or maintain weight can use the 100 calories per mile estimate to help balance their energy intake and expenditure.

It is important to note that the 100 calories per mile estimate does not replace more accurate measurements or calculations that are done in a research or clinical setting. And wearable devices and apps are easy ways to get a good idea of how your energy expenditure during a wider range of activities. But, if you want to know how many calories you burn during a run or how long you need to walk to offset what you eat, the 100 calories per mile estimate will give you a pretty good idea.

Earlier this month a runner attempted to complete a marathon (26 miles and 385 yards) in under two hours. For distance runners and sports scientists, a sub two-hour marathon is a bit like the four-minute mile once was—an arbitrary, but significant, goal. The current world record for the marathon is just under 2 hours and 3 minutes (2:02:57). To cut 3 minutes off that time would be a remarkable feat considering that it took almost 20 years to lower the record three minutes from 2:06 to 2:03. The continued quest for a sub-two hour marathon is the topic of my Health & Fitness Column in the Aiken Standard this week.

First, let’s put a two-hour marathon in perspective. To do it would require sustaining a running speed of over 13 miles per hour for two hours. Most runners I know would be hard pressed to complete the 385 yards at that pace…forget about the 26 miles that come before it! It is also more than twice as fast as the average marathon time of over 4 hours. If you are brave you can experience how fast this is yourself by getting on a treadmill and cranking the speed up to 13 miles per hour. Hang on, though, because you won’t last long!

The recent attempt to break the two-hour mark featured the accomplished Kenyan marathoner Eliud Kipchoge, whose personal record was just over 2:03. The effort was as much about running technology as it was about human performance. The shoes he wore were designed by Nike to be exceptionally light and provide extra recoil to propel the runner forward. The race was run on a Formula One track in Italy that was smooth and flat and was completed early in the morning when the weather was cool with low humidity.

During the race, a group of runners ran in front of Kipchoge to break the wind so he could draft much like race cars do. These runners also acted as pacers, keeping him at the right speed to break the record. There was even a pace car that projected a line on the road for the runners to follow. Water and sports drinks were provided by assistants on bikes so the Kipchoge didn’t need to slow down to replenish fluid and carbohydrates. In all, it was a perfect scenario to run a sub-two-hour marathon.

Despite all the preparation and efforts during the race, Kipchoge just missed the goal, finishing in 2:00:25—less than one second per mile off the mark! This suggests that breaking the two-hour barrier for a marathon is achievable, but is still a significant challenge. In fact, because of the pacing strategy used, this run is not considered a world record.

Other groups are also working to get a runner past the two-hour mark. One, led by sports scientist Yannis Pitsiladis, is taking the approach of enhancing training and to promote better performance. I have written about the physiological foundations of running performance related to the sub two-hour marathon previously.

While the two-hour marathon is still a goal for many, the sports science, technology, and training advances currently being explored exciting. Like the “shark skin” suits worn by swimmers and aerodynamic bikes used by cyclists, improvements in running technology are likely to be both beneficial and controversial. None of these advances can offset the physiological adaptations that result from years of dedicated training, so the best way to prepare for your next race is to put in time running, whether you are wearing the newest, fastest shoes or not!

If you play sports or exercise regularly you probably have experienced some sort of injury. Hopefully yours was just a minor muscle strain, joint sprain, or soreness that didn’t prevent you from continuing your exercise program. It is always best to address minor injuries before they progress to cause more lasting damage.

If you do sustain a muscle or joint injury you will probably ice the affected area to help it heal. But there are also several newer techniques that can help speed recovery. This is the topic of my Health & Fitness column in the Aiken Standard this week.

The most common recommendation for treating a minor exercise injury is to use ice to reduce swelling and speed healing. For example, an ankle sprain might be treated by sitting with the injured leg elevated while applying ice; later the joint might be wrapped with athletic tape to provide support and further reduce inflammation. This combination is called RICE—rest, ice, compression, elevation—and makes intuitive sense.

Several other treatments for sports injuries have become more commonly used thanks in part to their use by professional and Olympic athletes. This is also due to the realization that inflammation is a key component in tissue repair and reducing it with ice therapy might actually interfere with healing. More and more sports medicine professionals are using modalities— voodoo flossing, cupping, and kinesio taping—other than (or in addition to) RICE to treat many injuries.

The benefits of compression for injury healing can be achieved by tightly wrapping an injured area with a rubber band, called “floss,” for a short time, usually less than a minute. This technique, commonly called voodoo flossing, is used to increase joint mobility and speed healing of minor injuries. Tightly wrapping a joint does has several potential effects by which it can improve movement and reduce pain. This includes allowing tissues to move more freely and increasing blood flow to the injured area.

Cupping gained much attention when swimmer Michael Phelps appeared at a race in the 2016 Olympics with large red welts on his back. He wasn’t hurt, as many feared. Rather, he was using cupping as a technique to treat injury and improve performance. Cupping literally involves the application of glass or plastic cups to the skin for several minutes, typically 5–15 minutes. Using either vacuum or heat, the cups pull the skin away from the underlying muscle tissue, increasing blood flow and improving movement. While cupping may be new to most of us, it has been used since ancient times and factors prominently in traditional Chinese medicine.

While voodoo flossing and cupping have a role in treating injuries and improving performance in the training room, there is a relatively new modality that can be used during exercise to enhance performance. Kinesio tape, also called K-tape, is applied over specific muscles to reduce pain and improve movement. The tape pulls the skin away from the underlying muscle, which increases blood flow and enhances movement, much like cupping. The difference is that kinesio tape can be used during exercise, as many people first saw on the shoulders of beach volleyball players in the 2008 Olympics.

While many sports medicine professionals still recommend RICE as a first line treatment for minor injuries, they are increasingly utilizing these alternative treatments. With a little training, people can use these techniques at home to treat some of their own minor injuries. Obviously, it is important to learn how to properly do these treatments and evaluate whether they are working. Improper treatment can delay healing and may make some injuries worse, so these treatments might be best done by trained professionals. And some injuries do require attention by sports medicine professionals. That said, if you are looking for an injury treatment beyond RICE, voodoo flossing, cupping, and kinesio tape might be worth trying.

As Earth Day just passed, this is a good time to think about the impact we have on our environment. We should also think about what we can do to reduce that impact. The good news is there are ways we can “go green” that are good for our health and the health of our planet, as I explain in my Health & Fitness column in the Aiken Standard this week.

First, you can go green by replacing car trips with walking or cycling. Every mile you drive releases carbon dioxide and other pollutants into the environment. Additionally, spending more time sitting in your car can also have negative effects on your health and happiness. Walking or biking has no such effects on the environment and has important health benefits including improved fitness, weight control, and greater feelings of wellbeing. Despite the potential environmental and health benefits of replacing car trips with active transportation, 37% of Americans report not walking for transportation at all in a given week.

Obviously, walking or biking everywhere isn’t practical. But you could probably replace some car trips with active transportation. Most people commute less than five miles to work and nearly half of all car trips are less than two miles. Both are reasonable distances to bike or walk. If you have several places to go, you can always park in a central location and walk to each destination.

The second way you can go green is by eating more vegetables and fruits. Fruits and vegetables contain vitamins, minerals, and fiber and most are low in calories. At a minimum, you should eat five servings per day with an emphasis on fresh fruits and vegetables. You should also try to buy from area farmers. Eating locally grown food is good for you and the environment. Food production and delivery is second only to cars for fossil fuel use  and is the biggest contributor to greenhouse gas emissions. According to one estimate,  the food items that make up a typical meal travel about 1,500 miles each (as much as 100,000 miles for a whole meal in some places) to get to your table? Food from local farms is associated with fewer “food miles” and a lower environmental footprint.

Additionally, produce grown locally is picked at the peak of freshness, meaning it is richer in nutrients, not to mention flavor. By contrast, produce that is grown far away is picked before it is ripe, resulting in lower nutritional value. As an added benefit, the money you spend on food from local farms stays in our area, supporting farmers who live in our community.

Since you are eating more veggies, you can eat less meat. Raising animals for meat, milk, and eggs has a major impact on the environment. Over a quarter of land is dedicated to raising livestock, and almost 15% of total greenhouse gas emissions come from livestock. These animals also produce tons of manure every minute, at least some of which ends up polluting water supplies.

Finally, you can literally “go green” when you exercise. Being active outdoors leads to enhanced feelings of energy and diminished fatigue, anxiety, anger, and sadness compared to similar activity conducted indoors. Additionally, some research suggests that outdoor activity may improve attention in adults and children. Another advantage of exercising outdoors is that you might get a better workout because you will likely walk or run faster outdoors. Research shows that even though people tend to exercise at a higher intensity outside, it may feel easier. Much of the psychological benefit of outdoor exercise occurs in the first five minutes, so even short bouts of activity, like walking instead of driving a short distance, are meaningful.

So, as you celebrate Earth Day this week, think about all the ways you can go green—it’s good for you and the environment.

Eating nuts can be a tasty way to make your diet healthier. Nuts are beneficial because they are rich in healthy unsaturated fats, fiber, and essential vitamins and minerals. Nuts also contain omega-3 fats and natural plant sterols which, together, may help lower your blood cholesterol and reduce your risk of heaving a heart attack. But all foods that contain nuts are not equally healthy, as I explain in my Health & Fitness column in the Aiken Standard this week.

Although the specific nutrients vary among different nuts, all nuts are thought to be healthy. This includes tree nuts such as almonds, macadamia nuts, walnuts, and pecans, which have the most research to support their health benefits. But it also includes peanuts, which are actually legumes (like beans), not true nuts.

Research suggests that regular nut consumption is associated with a lower risk of dying from many of the leading causes of death, including heart disease and cancer. One study examined a host of lifestyle factors, including physical activity, smoking, and diet, in over 100,000 men and women for nearly 30 years.

The reduction of risk of death was greater with more frequent nut consumption. For example, the risk of death from all causes was 11% lower among men and women who consumed nuts once per week and 20% lower among those who ate nuts seven or more times per week. This was true for both peanut and tree nut consumption, suggesting that all nuts are beneficial.

It is important to note that the people in the study who ate the most nuts were also leaner, consumed more fruits and vegetables, less likely to smoke, more likely to exercise, and more likely to use multi-vitamin supplements. Although these other factors were controlled for in the analysis, common sense suggests that the benefits associated with nut consumption is likely due to a combination of these beneficial health behaviors.

The bottom line is that eating nuts as part of an overall healthy lifestyle is good for you. A person who eats in unhealthy diet, doesn’t exercise, and smokes is unlikely undo the negative health impact of their lifestyle simply by eating more nuts. Achieving the full benefits of nut consumption seen in the study also certainly means adopting other healthy behaviors.

The good news is that adding nuts to your diet is an easy change to make. A typical recommendation for nut consumption is 1-1.5 ounces per day. This is the equivalent of a handful of most nuts. The goal would be use nuts to replace a less healthy snack such as chips. A handful of nuts contains about 150-200 calories, similar to other snacks such a small bag of potato chips. The difference is that nuts contain healthy fats, vitamins, minerals, and fiber, which may fill you up more. Nuts are relatively inexpensive and portable, meaning you can take them with you for a snack. Nuts can also be added to salads and other dishes.

Keep in mind that you should focus on eating plain nuts to get the biggest benefits. Many nuts have added flavors in the form of coatings, glazes, and seasonings, which may be high in sugar and salt. Honey roasted peanuts and chocolate covered almonds are good examples of nuts that are essentially candy. These types of nuts should be eaten sparingly and for dessert, not as a snack.

Similarly, peanut butter (and other nut butters) are a healthy source of protein and energy. But many contain added sugar as some contain other ingredients like chocolate. In fact, many “nut” butters don’t contain nuts at all and are essentially frosting!

To learn more about the difference between plain nuts and nuts that are essentially candy, check out Candy and Soda for Breakfast!

So, go ahead and go nuts! Just remember to do it as part of an otherwise healthy diet and active lifestyle.