Tag Archives: VO2max

Dive in to aquatic exercise.

There is nothing that feels better on a hot summer day than going for a swim. But beyond being a fun way to cool down, swimming is a great way to get in shape, build muscle, and to help you lose (and maintain) weight. Lap swimming is about as aerobically demanding and burns as many calories as land-based exercise such as walking or jogging. (Obviously, it depends on the stroke you use and how fast you swim). Swimming is also an excellent exercise for injury rehabilitation or for people with conditions like arthritis.

The health and fitness benefits of swimming and aquatic exercise is the topic of my Health & Fitness column in the Aiken Standard this week.

Aqua_Aerobics


The fitness benefits of swimming are well established. Since swimming is a whole-body exercise it uses all of your major muscle groups, building strength, endurance, and aerobic fitness. Highly trained swimmers have VO2max values, considered the best measure of aerobic fitness, that are similar to runners and cyclists. If you have doubts about the fitness benefits of swimming, think back to the last Olympics and how muscular and lean the swimmers looked.

Depending on the stroke and speed, swimming ranges between 5 to 10 METs. (METs are units used to measure the intensity of activity; one MET is equivalent to sitting at rest) For example, doing the backstroke at a moderate speed is about 5 METs while swimming laps freestyle with vigorous effort is about 10 METs.

This range is similar to walking at 4 mph up to jogging at a 9 minute per mile pace. What if you are just spending time in the pool or lake rather than swimming laps? Swimming leisurely is 6 METs, still a decent workout.

Swimming is a great way to burn calories, too. Even at a moderate pace, swimming laps for 30 minutes can burn over 200 calories. The exact energy expenditure depends on the stroke (butterfly is highest, backstroke is lowest) and the speed, but for most people swimming will burn as many calories as spending the same amount of time exercising on land.

There are two major reasons for this. First, water is more dense than air, so you need to expend more energy to move your body through the water. Second, swimming is a whole-body exercise which requires more muscle activity compared to walking or jogging which mostly involve the legs.

You may be surprised to learn that novice swimmers expend more energy per lap than elite swimmers. For example, one study showed that competitive swimmers expend only 280 calories to swim a mile, while less experienced swimmers burn about 440 calories to cover the same distance. The reason for this is that experienced swimmers are more efficient, so they expend less energy.

Aquatic exercise is popular for both therapeutic and fitness purposes, especially for people who don’t tolerate exercise on land well. When you are submerged up to your waist, 50% of your weight is supported; when you are up to your chest, about 75% is supported. This reduces the impact of exercise in the water, perfect for people who have arthritis, osteoporosis, severe obesity, or who are recovering from injuries.

Exercise in the water doesn’t have to mean swimming laps. Water aerobics, aqua walking or jogging, and resistance training using foam “weights” or webbed gloves offer safe ways to increase strength and endurance for almost everyone. Most fitness facilities that have a pool offer group aquatic exercise classes and you can find instructions online for exercises that you can do in your own pool.

If you are interested in using your pool for exercise, you can find information about aquatic exercise in general here and links to suggested exercises here. You can learn more about aquatic exercise specifically for arthritis and fibromyalgia, too.

The hot summer weather makes swimming and other water exercise appealing. But even if you don’t use the time for exercise, spending time playing in the pool or lake can still burn as many calories as going for a walk and is a great way to have fun and cool down!


Nutrition, exercise, and health information can be confusing. 
But it doesn't have to be that way.
What can I help you with?
 drbrianparr@gmail.com | http://twitter.com/drbrianparr

Sports Science at the Winter Olympics

So, the 2014 Winter Olympics wrapped up with the closing ceremony yesterday. If you have been watching the Olympics you have seen some incredible performances. The competitors are among the fittest and most highly trained athletes in the world, both in terms of laboratory measures of fitness and in subjective evaluations of skill. Competing in the Olympics requires years of focused, intense training and some good luck.

In my Health & Fitness column in the Aiken Standard this week I take a look at the  physiology that goes in to training for and competing in the Olympics.

First, let’s look at the fitness. This is most evident in the endurance events like cross-country skiing and speed skating. The key to performance in long-duration events like these is for the muscle to contract repeatedly and forcefully without fatigue. In order to do so, the muscle must have a steady supply of oxygen and nutrients. These nutrients are delivered through the blood, which is pumped to the muscle by the heart. The muscle takes up and uses these nutrients to produce ATP, the form of energy used by the muscle.

After months and years of endurance training the heart gets bigger resulting in the ejection of more blood to the muscle. Within the muscle there is an increase in the number of capillaries, the small blood vessels that deliver blood to the muscle, and mitochondria, the part of the cell that produces most of the ATP. Together, these adaptations allow the muscle to produce more ATP without fatigue, allowing the athlete to sustain a higher intensity (skiing speed, for example) for a longer time without fatigue.

How fit are these athletes? In the laboratory we measure VO2max, the maximal rate at which oxygen can be used by the muscle to power exercise, during intense exercise. While we don’t have test data on most Olympic athletes, cross-country skiers tend to have the highest VO2max values, followed closely by distance runners and cyclists.

While all Olympic athletes are all very physically fit, other events rely more heavily on skill including figure skating and freestyle snow boarding. For example, in figure skating completing a triple axel involves leaping into the air, spinning three and a half times, and landing backwards. On a 4 mm wide blade. On ice. Or think about the triple cork 1440, a snowboarding trick that involves flipping three times in the air while doing four 360-degree turns.

The athletes who are able to successfully complete these maneuvers have practiced for years to develop the skill and confidence needed to perform them consistently in competition. These are some of the most obvious displays of athletic skill, but all events require good technique. The development of skill in addition to fitness is the main reason why athletes specialize in one area and you don’t see people competing in both downhill skiing and speed skating, for example.

Of course, there is a psychological aspect to Olympic performances. The motivation to put in the training time alone is remarkable. Even more impressive is the ability to focus on an event despite the distractions of the crowds, media, and pressure of competition. This combination of physical and mental preparation is rare—as rare as Olympic gold medalists!

The training and preparation followed by bobsledders provides a good model for what goes into creating an Olympic athlete.

But is training alone sufficient for Olympic-level performance? Could anyone who trains enough make it to the Olympics? The answer is no, because there is another important factor in athletic performance—luck. Luck refers to genetics, which determine potential for attributes like heart size and muscle characteristics. As much as 50% of performance in some events is attributed to genetics. One sports physiologist famously answered the question, “How do I become an Olympic champion?” with “pick the right parents!”

There is more that I am missing (on purpose, because I have a word limit in my column). One additional key factor is nutrition. Despite what Subway would have you believe, Olympic athletes don’t really eat a lot of sandwiches with Fritos on them. In fact, this is a good overview of what US Olympians eat to fuel their training and competition.

Even though most of us will never become Olympic champions we can still experience many of the same benefits of training. All athletes train to develop strength, endurance, and flexibility, which is exactly what we should do, too. And those attributes will help us perform better at work (and play) and help us live a longer healthier life. It will also help us appreciate the training, dedication, and good luck that the athletes bring to the Olympic games.