Tips for Running in Humidity

It's not (just) the heat that matters! How to cope with the muggy weather.

By

Liz Plosser; Image by Mark Matcho

Published July 10, 2013 In Runners World

 

Runners often obsess over weather reports, tracking the coolest time of day in which to run. But as anyone who's ever tried to finish a five-miler in steamy conditions knows, it's not just the temperature that matters, it's the humidity.

"Of all the climate measurements we take to assess heat risk for our runners, humidity is the biggest factor," says George Chiampas, D.O., the medical director of the Chicago Marathon. Humidity makes warm summer runs even more taxing because the higher the moisture content of the air, the hotter it feels. An 88-degree day with a relative humidity just under 40 percent, for example, will feel like 88 degrees. Hot, yes, but when humidity reaches 70 percent, that same 88 temperature feels like 100 degrees.

Unless you're lucky enough to live in Paradise, Nevada—the least humid city in the U.S.—here's how to cope when running in steamy conditions.

Why Humidity Matters
When you run, your core body temperature naturally rises, and your sweat glands produce droplets that carry excess heat to the surface of the skin, where it evaporates. But humidity prevents sweat from evaporating, so the heat stays put. "On a hot, humid day with no breeze, you have lost a key way to get rid of your building body heat, which can make running dangerous," says Michael Bergeron, Ph.D., a professor at the Sanford School of Medicine of the University of South Dakota.

If your body heats up and gets more and more dehydrated, it goes into survival mode, maintaining blood flow to your essential organs (to keep you alive) and to your skin (to regulate temperature). Less blood will flow to your GI tract, which will make the digestion of sports drinks or gels difficult, and you may feel nauseous as a result. You may also find you are more prone to side stitches when you are overheated—especially if your breathing becomes shallow and uneven. And your heart rate will escalate as your ticker and lungs work overtime trying to deliver oxygen throughout your body, Dr. Chiampas says.

But wait, there's (ugh!) more. If you continue to gut it out, your brain temperature will rise, which makes matters worse: Your ability to assess your own body temperature will become difficult (runners often report feeling chilled or goosebumpy when they're overheating). You can also start to lose control over body mechanics (your form and footing will get sloppy), and your mental abilities may start to break down (you may feel dizzy or disoriented).

"Your temperature can spike in minutes," Bergeron says. "If you're running a 5-K or a 10-K on a hot day, you can jack up your body temperature quickly." Also, it's a myth that newbies or not-fit-enough runners are the ones who suffer in hot, humid conditions. In fact, competitive athletes may be more prone to heat-related illnesses because the faster you run, the more body heat you generate. "As humidity increases, thermal strain and premature fatigue increase exponentially, and so running at your normal pace will feel very difficult," Dr. Chiampas says. It's also important to recognize that feeling sluggish on a sticky day doesn't indicate a lack of fitness or a lapse in mental toughness—it's your body's physical response to a stressful environment.

Of course, some people handle heat and humidity better than others. Body size is one factor—the more body mass you have, the more insulation and load you carry and the more heat your body generates, which makes it easier for you to overheat. Age is another variable—over time, your body becomes less adaptable to heat; age-related changes to sweat glands can decrease sweat production and reduce the body's ability to cool itself effectively. Also, sweat content varies: Some people lose more sodium in their perspiration than others, and that can impact performance and increase risk of cramps if these salty sweaters don't take in enough electrolytes. Where you live also plays a role: It takes generally 10 to 14 days to acclimatize to hot and humid conditions. People who train in humid parts of the country will become naturally used to muggy conditions and probably fare better at, say, an August East-Coast race than someone who travels in from the West Coast, where humidity is generally lower.

Slogging On
You might think the best times to run are early morning or evening, or cloudy, rainy, or not-crazy-hot days. But all of those can be incredibly humid. When you check the weather report, don't pay attention to just the temperature. The Heat Index combines temperature with relative humidity to give you apparent temperature—how it actually feels outside. Relative humidity doesn't become a factor until it reaches about 40 percent—below that, you'll have a comfortable run; above that, it could impact your performance. For example, a 75-degree day with zero percent humidity will feel like 69 degrees. But in 100-percent humidity, 75 degrees will feel like 80. (Though there is no simple formula for calculating Heat Index on your own, it's easy to find on weather Web sites and apps.) The National Weather Service issues a Heat Advisory when the Index is expected to exceed 105 for at least two consecutive days.

In those conditions, if you are intent on getting in a quality workout, your best bet is a treadmill in an air-conditioned room. Otherwise, opt for a shaded path (versus heat-absorbing roads), run close to water (bodies of water offer breezier conditions), and take walk breaks. It's essential to hydrate properly and let go of any time-based goals—run by feel instead of pace. When temperatures go from 75 to 90 degrees, heart rate can increase by 10 to 20 beats per minute, which will make your perceived effort much greater. Add humidity to the mix, and the effect will be even more significant, Bergeron says.

Be mindful of the early warning signs of heat exhaustion and heat stroke: fatigue, nausea, dizziness, headaches, tingly skin, and confusion. Call it quits if you experience any of them—even if you haven't reached the end of your run or the finish line yet.

The good news? You can teach your body to respond more efficiently in the heat. Signing up for a race in the second half of the summer will give you a few weeks of heat training under your fuel belt, so you'll struggle less than you would at the beginning of the season. And any training you do now will only make your fall runs all the more enjoyable.

When faster is not better!

Your resting heart rate can tell you a lot about how fit you are-and perhaps some other things about your health. This refers to the number of times your heart beats per minute when you are at rest; 50 to 100 is considered normal, though most people fall in the 60-to-80 range.

            Resting heart rate varies from person to person and even over the course of the day, due to genetics and other factors, such as temperature. In general, slower is better, since a heart rate faster than necessary for good health puts unneeded stress on blood vessels and the heart. People who do acrobic exercise (such as jogging or cycling) and become very fit tend to have a lower resting heart rate because such activities strengthen the heart, so it pumps more blood with each contraction.

            On the flip side, a growing body of research has been finding an association between faster resting heart rate and increased risk of heart disease and premature death, independent of fitness level and other known cardiovascular risk factors, such as high blood pressure, high cholesterol, and being overwright.

            Recently, a Danish study in the journal Heart, which followed 2,798 healthy middle-aged and older men for 16 years, found that for every 10-beats-per-minute increase over 50, the risk of death rose by 16 percent, after other factors that can affect heart rate were accounted for.

            “These results suggest that in healthy subjects, elevated resting heart rate is not merely a marker of poor general fitness but an independent risk factor,” the researchers concluded.

            Previous studies have linked higher resting heart rate to poorer health outcomes in both healthy people and those with heart disease, and in both men and women. According to a review paper in Progress in Cardiovascular Diseases a few years ago, resting heart rate may be a better predictor of premature death than cholesterol and blood pressure−thought there’s no consensus on what an optimal heart rate is and where increased health risks begin.

            BOTTOM LINE: If your resting heart rate is at the high end of the normal range, talk to your doctor. If you are physically fit, there may not be anything you need to (or can) do about it, but it can serve as one more piece of information your doctor can use in evaluating your heart disease risk and how to best manage your overall health. If you are not in good physical condition, aerobic exercise may bring down your resting heart rate somewhat over time−this is called the “training effect”−though it may take a long time for this to occur, and not every exerciser experiences it.

Univ. California, Berkeley Wellness Letter

Sunglasses...Style or Protection?

Eye on Sunglasses

Many people choose sunglasses by how they look and feel. But the most important feature to consider is how well they shield your eyes from ultraviolet rays (high-frequency invisible energy emitted by the sun), as well as blue light (high-frequency visible light). Chronic ultraviolet (UV) exposure is implicated in a range of eye conditions, including cataracts, benign growths on the surface of the eye, skin cancer on the eyelid and around the eyes, and even melanoma of the eye itself. Blue light is particularly damaging to internal eye tissues and over time may permanently damage the retina, leading to macular degeneration.

Sun damage is cumulative, so the more time you spend outdoors with your eyes unprotected, the greater your lifetime risk. The good news is that it’s not hard to find affordable sunglasses that are fashion-forward and protective.

Everyone who spends time outside should wear sunglasses. That includes children (whose eyes are especially vulnerable to UV) and people who wear contacts (even if UV-treated, they don’t cover the whole eye). Sunglasses are a necessity for people who are sun-sensitive due to medications (such as tetracycline) or other reasons, and for those who have had cataract surgery, especially if they have an older intraocular lens that provides no UV protection. Light-colored eyes are especially vulnerable to UV. Even on overcast and hazy days, your eyes can be exposed to significant UV radiation.

Here’s more reason to wear a pair: Very bright sunlight can irritate eyes−and even burn the cornea, a temporary  but painful condition called photokeratitis or “snow blindness.: Sunglasses also shield eyes from wind, dust, and drying, and they help reduce glare, which can be hazardous when driving, biking, or playing sports.

What to look for

There are o federal standards for sunglasses, and labels are inconsistent and confusing. A tag or sticker that simply says “blocks UV” or “UV-absorbent,” for instance, is meaningless because it doesn’t tell you how much UV is blocked. Better choices are sunglasses that claim to block most or all UV (“99-100
%UV absorbent” or “UV 400,” for example), though there is no independent verification for this. And while the American National Standards Institute (ANSI) sets voluntary standards (Z80.3 codes) for UV protection of sunglasses, you’re not likely to see these labels, and they don’t guarantee that the glasses have actually been inspected.

            One way to be certain that your sunglasses are blocking most or all UV is to have an optician test them using a photo spectrometer (often called a UV meter). It’s a good idea to have old sunglasses tested, since some of the UV coating, if one was applied, can be lost over time through scratches and abrasions. An optician can also coat sunglasses, if necessary. 

More general pointers:

■ Both clear glass and plastic lenses naturally filter out some UV light (polycarbonate plastic, in particular, blocks nearly all UV). But maximal UV protection comes from clear chemicals that are incorporated into the lenses during manufacture or applied as a coating.

■ Darker lenses don’t mean greater UV protection. In fact, unless darker lenses are fabricated to block UV, they can be more harmful than wearing no sunglasses, because they can cause pupils to dilate, allowing more UV to enter your eyes. Darker lenses do, however, block more visible light and minimize glare.  They should be dark enough so you don’t see your eyes when you look in the mirror, but light enough so you can see curbs, stop lights, and stairs.

■ Colored lenses reduce visible light, but color has nothing to do with UV protection. Yellow, amber, and orange lenses block the most blue light and enhance contrast, but can distort colors. Brown also blocks significant blue light. Gray and brown lenses produce the least color distortion and are good for all-around wear and driving. Green distorts minimally. Avoid blue-tinted glasses, which let in more blue light.

■ The larger the frames, the better.  Wrap-around glasses block light coming from the side, but may cause distortion.

■ You should be able to find an adequate pair of sunglasses for $20 to $60. More expensive ones are not necessarily better, but cheap ones (less than $10) are more likely to have optical imperfections.

■ To check lens quality, hold the glasses at arm’s length and look at a straight line in the distance. When you move the glasses across that line, the line should not bend.

■ If you wear prescription glasses, you can buy prescription sunglasses or glasses with photochromic lenses (see below). You can also get sunglass “clip-ons” for your regular frames−or “click-ons” that attach magnetically. At a minimum, your regular glasses should have added UV protection.

Beyond UV protection

You can find sunglasses with all kinds of extra features. Just make sure they are UV treated, since these features are not related to UV protection.

      Polarized lenses cut down on reflected glare, which is good if you are driving, boating, fishing, or skiing, for example−but they make it harder to see cellphone, ATM, and dashboard displays.

      Mirrored lenses can be helpful in very bright conditions, though they scratch easily. The tint of the mirror coating doesn’t affect color perception.

      Photochromic lenses automatically darken and lighten depending on the ambient light. It takes about 30 seconds for them to darken in bright light, but about five minutes to fully lighten when you go inside.

      Gradient lenses are shaded darker at the top and lighter at the bottom, which cuts light from the sky but allows you to see the car dashboard and horizon well. They also let you see your step as you enter an area with less light. Double-gradient lenses are dark at the top and bottom and are good for skiing, boating, and water sports.

      Ultra-impact-resistant lenses are good for certain sports and occupations. The FDA requires all eyeglasses to be impact-resistant, but polycarbonate lenses are the most shatterproof. They scratch easily, however, so look for ones with scratch-resistant coatings.

Berkeley Wellness.com August 2013

Do You Have Control of Your Health?

Taking charge of your health

Top 5 tips to help you become proactive in your health care.

We rely on doctors and other providers to diagnose and treat medical conditions, but the most important person in your health care is you. “Being proactive in your health care empowers you,” says Dr. Julie Silver, an associate professor at Harvard Medical School. “We can’t completely control our health, but there are things that we can take charge of that will make a positive difference.” By starting with a few small changes, you’ll gain a sense of control quickly.

1 Keep track of your health information.  Keep a written record of your health: a current list of prescriptions and supplements that you take; when your doctor wants you to report any measurements you make at home such as your weight, blood pressure, or blood sugar; when each of your last screening tests was done.

Doctors who use electronic health records can print these out for you.

Your individual targets for measurements made at home may vary depending on your age and overall health, but for most adults blood pressure should be less than 120/80 mm Hg. You’re considered to have impaired fasting glucose, part of the definition of prediabetes, if your fasting glucose level is between 100 and 125mg/dL. And your cholesterol levels are in the healthy range if the HDL is above 40mg/dL and the LDL is below 100 mg/dL.

2 Don’t miss your screening tests.  Your doctor should set targets for how often you need different screening tests. Check with your doctor if you think you’re due for a test. See our chart on this page for general recommendations.

3 Speak up about your health. Ask questions and state preferences when it comes to treatment. Share new symptoms in detail with your physician. And if your doctor orders tests, here are some important questions to ask:  What is this test

Do you think the symptoms indicate? Why is this test necessary? What therapies are available? What is the prognosis? Are there any additional costs beyond my anticipated insurance reimbursement?

4 Get moving. Regular exercise has more power to protect your health than any medicine ever invented. It reduces your resting heart rate, and allows your heart to work more efficiently. Exercise also lowers blood pressure and improves your cholesterol and the way you process blood. That can help prevent heart disease, stroke, and some forms of dementia. Exercise also causes nerve cells to release proteins called neurotrophic factors. Research in lab animals has shown these proteins stimulate the growth of new brain cells, improve neural connections in the brain, and help to regulate metabolism, energy, and mood. Exercise may also delay cognitive decline.

Strive for at least 150 minutes per week of moderate-intensity exercise, such as brisk walking. If you’re unable to get aerobic exercise because of a health condition, weight lifting has also been shown to be effective at staving off diabetes and osteoporosis.

 5 Eat your way to good health.  Get rid of the junk-saturated fats, high-sodium foods, and prepackaged foods. Replace them with fresh, natural food. The Harvard School of Public Health recommends at least 4 ½ cups of vegetables and fruits a day, including dark leafy greens, and anything that’s a rich yellow, orange, or red color, such as tomatoes, oranges, strawberries, red peppers, sweet potatoes, carrots, and bananas. The Centers for Disease Control recommends keeping protein to 10% to 35% of your daily diet, and of that, the healthiest sources of proteins include lean meats, poultry, and fish, and plant-based proteins, such as nuts and beans.

Your diet is also linked to your weight, and maintaining a healthy weight has a direct impact on your health. Weight loss is good for your blood pressure and your cholesterol, for processing glucose and insulin, and for reducing inflammation and relieving joint pain.

“Taking charge of your health involves changing specific behaviors,” says Dr. Silver. “This takes effort, but over time becomes a habit that is really simple. The hard part comes first-changing what you are doing. But after a while, you’ll do it without much thought.” ☻

Harvard Health Letter – 6/2013

Healthy Choises... Are you Making Them?

Today’s baby boomers are generally healthier than their parents, right? After all, this generation has been dubbed the “Healthiest Generation” because of having the longest life expectancy of any of the previous generations – and has also had many health advantages their parents did not have. But, surprisingly, research shows that many in the aging baby boom generation are actually LESS healthy than their parents.

Researchers have discovered that the 78 million Americans born between 1946 and 1964 (baby boomers) have more diabetes, obesity, hypertension and high cholesterol than their parents’ generation. This is despite having a longer health expectancy and other advantages, like advances in medical care and public health campaigns promoting healthier lifestyles.

Americans have long thought of the current generation as being healthier than previous ones, but baby boomers seem to be ending that trend. In fact, only 13% of baby boomers rate their overall health as ‘excellent’, compared to 32% of the previous generation at the same age.

According to Dr. Dana King:

“Baby boomers are living longer, so I think there may be presumptions … that they are the healthiest generation. But they are not in excellent health while they are waiting around to live two to three years longer. Unfortunately they may be living longer with a greater burden of chronic disease, and more disability. It’s not exactly a good public health outcome.”

So, why, despite all the advantages, aren’t baby boomers enjoying better health than their parents? Experts suspect the biggest culprit is obesity. More Americans are overweight or obese than ever before, triggering a host of chronic medical conditions. And, advances in medical care may only be treating the symptoms (for example, blood pressure medication) rather than the root causes of obesity, thus perpetuating the problem.

Consequently, many baby boomers are becoming sicker sooner and experiencing a lower quality of life than their parents did at the same age – while living a few years longer.

The good news is that this trend doesn’t necessarily have to be your reality (or that of a boomer you care about):

- YOU have the power to lose weight, exercise more, eat better and otherwise shift into a health-promoting lifestyle.

- YOU have more control of your quality of life now, and in the future, than you may realize.

- It’s YOUR choice.

What are you going to do about it?

Source: http://healthland.time.com/2013/02/05/baby-boomers-not-the-healthiest-generation/?iid=hl-main-lead