Bad Air Affects Women More Than Men In Marathons

Poor air quality apparently affects the running times of women in marathons, according to a study by Virginia Tech civil and environmental engineer Linsey Marr.  Her findings come from a comprehensive study that evaluated marathon race results, weather data, and air pollutant concentrations in seven marathons over a period of eight to 28 years.

The top three male and female finishing times were compared with the course record and contrasted with air pollutant levels, taking high temperatures that were detrimental to performance into consideration.

Higher levels of particles in the air were associated with slower running times for women, while men were not significantly affected, Marr said. The difference may be due to the smaller size of women's tracheas, which makes it easier for certain particles to deposit there and possibly to cause irritation
"Although pollution levels in these marathons rarely exceeded national standards for air quality, performance was still affected," Marr said.

Her work, done in collaboration with Matthew Ely, an exercise physiologist at the U.S. Army Research Institute of Environmental Medicine, appears in the official journal of the American College of Sports Medicine, Medicine and Science in Sports & Exercise.

Her studies were conducted where major U.S. marathons are located, such as New York, Boston, and Los Angeles, where pollution tends to be highest. Although the person might not be significantly impacted by low-yet-still-acceptable air quality, marathoners are atypical because of their breathing patterns, she said.

"Previous research has shown that during a race, marathon runners inhale and exhale about the same volume of air as a sedentary person would over the course of two full days," Marr said. "Therefore, runners are exposed to much greater amounts of pollutants than under typical breathing conditions."
Particulate matter appeared to be the only performance-altering factor in air quality, with carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide levels not impacting race times.


Source: Virginia Tech and Marr, Linsey C.; Ely, Matthew R. Effect of Air Pollution on Marathon Running Performance :. Medicine & Science in Sports & Exercise, 2010; 42 (3): 585 DOI: 10.1249/MSS.0b013e3181b84a85

See also: Barefoot Is Better and Running Addicts Need Their Fix

Vancouver Olympians Prepared For High And Low Altitudes

Lindsey Vonn winning gold

For winter sports athletes, including Olympians competing in Vancouver this week, the altitude of the sports venue can have a significant impact on performance, requiring athletes in skill sports, such as skating, ski jumping and snowboarding, to retool highly technical moves to accommodate more or less air resistance.

When considering the challenges and benefits of training and performing at sea level verses altitude, people often think of the effect altitude can have on oxygen delivery to muscles -- at higher altitudes, the body initially delivers less oxygen to muscles, which can result in fatigue occurring sooner during exercise. Higher altitudes also have less air density -- about 3 percent reduction for every 1,000 feet -- which can result in faster speeds in ski and skating races due to less aerodynamic drag, but can also affect timing and other technical components in skill sports.

"Many athletes perform thousands upon thousands of moves so they get a certain motor pattern ingrained," said Robert Chapman, an expert in altitude training at Indiana University. "A different altitude will change the feedback they get from balance and proprieception. In an endurance sport such as cross country skiing or biathlon, for competition at altitude it takes about 10-14 days to adjust. For a skill sport, it's harder to judge how long it will take to acclimate to the reduced air density at altitude. Hopefully, these athletes have incorporated this into their training, maybe in the last year or for a period of time, not just the two weeks leading up to competition."

Chapman, an exercise physiologist in the Department of Kinesiology in IU's School of Health, Physical Education and Recreation, wrote about the topic in a special Winter Olympics issue of the journal Experimental Physiology.

The Winter Olympics are being held in Vancouver, British Columbia, which is practically at sea level. The ice events also are nearly at sea level, with other venues ranging from altitudes of around 2,600 feet for the sled events to around 5,000 feet for women's and men's downhill skiing.

Shaun White enjoying some altitude

Chapman said fans should expect few record times in speed skating events because of the low altitude and greater air resistance facing athletes. He and his co-authors note in their paper that current world records for men and women in every long-track speed skating event from the 500-meter to 10,000-meter races were set in Olympics held in either Calgary, at an altitude of 3,400 feet, or Salt Lake City, with an altitude of 4,300 feet. They note that every Olympic record for all individual event distances was set at the 2002 Olympic Games in Salt Lake City, with none topped in the 2006 Winter Olympics held in Turin, which lies at an altitude of 784 feet.

"The general thought is that altitude slows you down because you have less oxygen going to your muscles," Chapman said. "But at altitude, just as it is easier to hit a home run in the thin air of Denver, speed skaters in Calgary and Salt Lake City could skate faster, move through the air faster, because there was less drag. Eight years after Salt Lake City, we have natural improvements that you'd expect to see involving training, coaching and technology, but we won't see many records in Vancouver. It doesn't mean the athletes are worse, if anything they're probably better. It's the effects of altitude on athletes' times."

Air density can have a dramatic effect on ski jumping, he said, requiring athletes to change the angle of their lean depending on the altitude. Chapman said the women's and men's Olympic downhill skiing, freestyle skiing and snowboarding events take place at higher altitudes this month and could require technical adjustments by the athletes.

Chapman and his co-authors make the following recommendations concerning training and performing at altitude:

• Allow extra time and practice for athletes to adjust to changes in projectile motion. Athletes in sports such as hockey, shooting, skating and ski jumping may be particularly affected.
• Allow time for acclimatization for endurance sports: Three to five days if possible, especially for low altitude (1,640-6,562 feet); one to two weeks for moderate altitude (6,562-9,843 feet); and at least two weeks if possible for high altitude (more than 9,843 feet). Chapman said altitude affects breathing, too, with breathing initially being harder at higher altitudes.
• Increase exercise-recovery ratios as much as possible, with a 1:3 ratio probably optimal, and consider more frequent substitutions for sports where this is allowed, such as ice hockey. Recovery refers to the amount of time an athlete eases up during practice between harder bouts. If an athlete runs hard for one minute, following this with three minutes of slower running would be optimal before the next sprint. The recovery period gives athletes more time to clear lactic acid build up from their muscles.
• Consider the use of supplemental oxygen on the sidelines in ice hockey or in between heats in skating and Alpine skiing to help with recovery. Chapman said this helps calm breathing, which can be more difficult at altitude.
• Living at high altitudes while training at low altitudes can help athletes in endurance sports improve performance at lower altitudes.

See also: Wind Tunnel Is A Drag For Olympic Skeleton Riders and Aerobic Efficiency Is Key To Olympic Gold For Cross-Country Skiers

Source: Indiana University and Altitude training considerations for the winter sport athlete. Experimental Physiology

I Run, Therefore I Drink?

Here’s a question for your buddies at the next golf outing or bowling league night: Are we more active because we drink more or do we drink more because we’re more active? Recent research showed that there is a correlation between the two, but could not offer a solid reason.

Either way, another study claims the combination of moderate alcohol use and exercise will help our hearts more than just choosing one over the other.

Michael French, a health economics professor at the University of Miami, and his colleagues dug into data from the 2005 Behavioral Risk Factor Surveillance System, a yearly telephone survey of roughly 230,000 Americans, and found a surprisingly strong positive correlation between the levels of alcohol intake and exercise.  For both men and women, those who drank at least some alcohol exercised 7.2 minutes more per week than non-drinkers.

While that may not seem like much, the study showed that the more booze, the more minutes spent sweating. Light, moderate, and heavy drinkers worked out 5.7, 10.1 and 19.9 minutes more per week, respectively. Also, drinking resulted in a 10.1 percent increase in the probability of vigorous physical activity.

Now, that doesn’t mean that these folks were drinking while exercising, nor that it was necessarily good for them to engange in more than light drinking. Instead, French and his team, who have studied many facets of alcohol abuse and its triggers, are trying to make sense of this correlation that seems too strong to ignore. It seems counterintuitive to traditional views that if people engage in one unhealthy behavior, like excessive drinking, that they will most likely engage in other unhealthy behaviors, like physical inactivity.

French suggests that heavy alcohol use may be masked by the appearance of a healthy lifestyle and cautions physicians not to jump to conclusions.

“For example, taking into account only the patients’ levels of physical activity and perhaps diet would overlook potential alcohol use problems that could be detected and treated,” French writes. “Physically active individuals who engage in problematic drinking are often ‘‘healthy looking,’’ because alcohol use consequences are sometimes delayed.”

The study appears in the September/October issue of American Journal of Health Promotion.

Maybe we exercise more because we know how many calories those beers and mixers are adding to our waistlines. Even so, Danish researchers found that we’re still better off combining moderate alcohol consumption with exercise.

Morten Gronbaek, epidemiologist with Denmark’s National Institute of Public Health, and his team surveyed 12,000 people over a 20-year period to determine the cardiovascular effects of alcohol use and exercise. They divided the population into four groups: those who did not drink or exercise; those who had both moderate levels of alcohol use and exercise; and those who either just drank or just exercised at moderate levels.

The group with the highest risk of fatal ischaemic heart disease, a form of heart disease characterized by a reduced blood supply to the heart, were the non-drinking, non-exercisers. Choosing either moderate drinking or moderate exercise provided a 30 percent decrease in risk factors. However, drinking and exercising, (not necessarily at the same time), showed a 50 percent lower risk.

Their findings were detailed in the European Heart Journal.

“Being both physically active and drinking a moderate amount of alcohol is important for lowering the risk of both fatal IHD and death from all causes,” Gronbaek concluded.  Of course, the key is moderation, defined in the study as one drink per day for women and two per day for men. Also, Gronbaek warns that there is no heart benefit until a certain age.

“You wouldn’t advise everyone to drink,” he said. “You shouldn’t even think about doing it until age 45 or 50. There’s absolutely no proof of a preventative and protective effect before age 45.”