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How does air pollution affect physical performance?

It is known that exposure to air pollutants during exercise may affect your health and performance, but what can you do about it?

Inhalation of major air pollutants has been found to decrease lung function and exacerbate symptoms of exercise-induced bronchospasms, including coughing, wheezing, and shortness of breath.  In order to meet oxygen demands during light- to moderate-intensity exercise, you take in more air with each breath. And when you breathe through your mouth, you bypass the nose’s natural filtration of large particles and soluble vapors. As your exercise intensity increases, you breathe faster and deeper, which also increases the amount of pollution inhaled and the depth it travels into your respiratory system.

If you live in or near a busy city, you are exposed to even more combustion-related pollutants—such as nitrogen oxides (NOx), carbon monoxide (CO), particulate matter (PM), and ozone—that can inflame your airways and worsen asthmatic responses. Exposure to freshly generated emissions is most common near areas of high vehicular traffic.

While indoor exercise is often a good alternative to limit exposure to outdoor pollutants, some indoor conditions may be just as toxic. Nitrogen dioxide (NO2)—the more toxic NOx—is usually higher in gas-heated homes and indoor areas with poor ventilation. Carbon monoxide poisoning is also more likely to occur indoors. When carbon monoxide is in your system, the blood carries substantially less oxygen, reducing performance and eventually leading to carbon monoxide poisoning. Be sure to choose well-ventilated areas for indoor exercise.

Particulate matter and ozone are two significant pollutants you may be exposed to outdoors. Inhalation of high levels of particulates has been shown to reduce exercise performance as much as 24.4% during short-term, high-intensity cycling. Women may be more vulnerable than men to certain particulates, associated with greater decrements in performance. Ultrafine particle concentrations are highest in freshly generated automobile exhaust, and these small particles can be carried deep into the lungs. However, the further away you are from fresh exhaust, the less concentrated the particulates.

Bad ozone occurs lower in the atmosphere; it is not directly emitted into the air but is created from chemical reactions between NOx, volatile organic compounds (VOCs), heat, and sunlight. Ozone levels also are higher in summer than in winter; and especially in larger, hotter cities, concentrations tend to peak around midday when solar radiation is highest. Exposure to ozone during exercise has been found to increase resting blood pressure, reduce lung function, and decrease exercise capacity.

The risks associated with not exercising at all are far greater than the risks of exercising outdoors; it just takes a little more planning on days and in conditions when pollution is bad.  When planning outdoor exercise activities, follow these tips to limit your exposure to pollutants:

  • Avoid exercising in areas of heavy traffic, such as along highways and during rush hour.
  • During summer, exercise earlier in the morning, when ozone levels and temperatures are not as high.
  • Check the domestic or international air-quality ratings to determine if it’s safe to exercise outside. Limit your time outside on Code Red and Code Orange days. Environmental conditions on these days are not healthy, especially for children, the elderly, and people with existing respiratory conditions.
  • Exercise indoors when the air quality indicates high ozone and particulate levels.
  • Before any demanding physical activity, limit your carbon monoxide exposure by avoiding smoky areas and long car rides in congested traffic.

Stimulants found in weight-loss product

The weight-loss dietary supplement product Dexaprine has been found to contain undeclared active substances and has been removed from the Dutch market. Consumers should be aware of the reports of adverse events.

Last summer the Netherlands removed the weight-loss dietary supplement product Dexaprine from the market due to reports of serious adverse events, but the results of research into the cause has just been released. A recent article in Drug Testing and Analysis described at least 26 cases of Dexaprine toxicity reported to the Dutch Poisons Information Center. Testing revealed the existence of “a cocktail of synthetic stimulants” including synephrine, oxilofrine, deternol, yohimbine, caffeine, and theophylline, and possibly ß-methyl-ß-phenylethylamines. (Problematic forms of phenylethylamines, including ß-methylphenylethylamine. were discussed in an April 2014 article in the New England Journal of Medicine.) For more information about tainted weight-loss dietary supplements, see the Food and Drug Administration’s information. Note that this product is still available in the U.S. and online.

Can you spot a red flag?

Choose supplements safely. Learn how to spot red flags.

When something sounds too good to be true, it probably is. Dietary supplements are popular among military personnel, and it’s important to be able to spot the red flags—warning signs of potential problems—when considering a product. Read the OPSS FAQ on how to spot these red flags to help make an informed decision. And be sure to check back often for new FAQs.

Revisiting DMAA

Products with DMAA are disappearing quickly since the April 2013 announcement by FDA that DMAA is illegal, but some are still available. Check our updated list to make sure you don't inadvertently buy them.

HPRC presents its shortest list to date of still-available Dietary Supplements/Products Containing DMAA! Since our last update in December 2013, 20 more products have been discontinued or reformulated to remove DMAA, and even more have disappeared from Internet retail sources altogether. Currently, we have found only 41 products (out of more than 200 once on the list) that still appear to be in manufacture, in many cases from non-U.S. sources.

Since its April 2013 announcement that DMAA is illegal as a dietary supplement ingredient, FDA has cracked down on manufacturers and suppliers in the U.S. As an example, an FDA News Release last November highlighted the seizure of more than $2 million in products from a single company. For more about DMAA from FDA, read their “DMAA in Dietary Supplements” web page.

Keep your eyes on the road

HPRC Fitness Arena: Mind Tactics, Total Force Fitness
Filed under: Driving, Safety
Distracted driving is dangerous. Check out this resource dedicated to minimizing distractions and increasing your focus on the road.

Have you found yourself checking your phone while driving? Is it more than just occasionally? Driving while distracted is simply unsafe. According to the official U.S. government website (see link below), distracted driving “is any activity that could divert a person’s attention away from the primary task of driving”—such as texting, using a cell phone, checking your hair or makeup, shaving, brushing your teeth, or just talking to your passengers. The “most alarming distraction,” according to their site, is texting, and they give an example of how it makes you blind to the road for the entire length of a football field. According to the Department of Defense Instruction 6055.04 (April 20, 2009; Incorporating Change 2, January 23, 2013), all drivers should refrain from text messaging, using cell phones, or using other hand-held electronic devices unless the vehicle is safely parked or the person is using a hands-free device. This regulation is for everyone’s safety, so put your phone away. Keep your eyes on the road and don’t drive distracted. For more information, including frequently asked questions, check out

What’s the story with OxyELITE Pro?

Why has OxyELITE Pro been recalled? Read the OPSS FAQ to find out.

Two versions of OxyELITE Pro have been removed from the market in the past year. Read the Operation Supplement Safety (OPSS) FAQ to find out why, and to get more information from the Food and Drug Administration (FDA). Also, be sure to check back often, as we add answers to other questions about ingredients in performance-enhancing and weight-loss supplements and how to choose supplements safely.

If you have more questions about a particular dietary supplement ingredient or product, please use our “Ask the Expert” button located on the OPSS home page.

DMAA products dwindle

HPRC has again revised its list of DMAA-containing products, and most U.S. manufacturers and supplier have either eliminated such products or reformulated them to eliminate DMAA.

In April, FDA announced that the substance was illegal for use as an ingredient in dietary supplements, after which the number of products that contained it rapidly declined.

Only 19 products were added to the list over the past 12 months; none were actually new to the market, but just ones that came to our attention as other products with DMAA became unavailable. By comparison, 46 products were discontinued/reformulated, and 86 DMAA-containing products (or versions of products) appear to have disappeared completely from online retail availability. Only 61 products remain on the “active” list, and many of these are from non-U.S. sources; some still on the list may have eliminated (or are about to eliminate) DMAA, but their manufacturer/distributor websites are unclear as to their status.

HPRC will continue to update its list and report of “Dietary Supplement Products Containing DMAA,” with the most recent version dated  December 2014, but updates will appear less often than in the last two years.

New year, new coveralls for the Navy

HPRC Fitness Arena: Environment, Total Force Fitness
Filed under: Navy, Safety, Uniforms
By early 2014, more sailors will be better protected against fires with new flame-resistant coveralls.

Before 2013 comes to a close, the Navy will begin distributing Flame Resistant Variant (FRV) coveralls to all Sailors assigned to surface ships and aircraft carriers. Previously, only Sailors working in engineering departments, on flight decks, and in other high-risk areas were issued flame-resistant clothing. However, a recent review found that the highest risk of severe injury from flames was from major fires or explosions, which puts any Sailor at risk. Tests revealed that the Navy Working Uniforms (NWU) type I, made of a polyester cotton blend, are susceptible to melting in a fire, which could cause even greater injury to the wearer. The new FRV coveralls are 100% cotton with a fire-resistant coating, which is self-extinguishing. The Navy plans to improve and standardize all coveralls over the next couple years by combining the protective effects of flame resistance, arc-flash protection, and low-lint specifications into one safe and effective uniform.

Happy Halloween!

Happy Halloween from HPRC! Review some safety tips for a great holiday this year.

HPRC wishes you a very Happy Halloween! Halloween can be a fun family holiday, with costumes, trick-or-treating, parties, and food. But before you jump all in, review some safety tips to keep this holiday fun and safe! The Centers for Disease Control and Prevention highlights some tips: Don’t trick or treat alone or stop at dark houses and do wear reflective tape, examine all candy for evidence of tampering, avoid homemade treats, and use a flashlight. Visit the CDC website to read the full article.

Social media “red flags”

You shouldn’t believe everything you read on social media, especially when it comes to dietary supplements and sports products.

Sports products and dietary supplements are often discussed on social media, but think twice before taking other’s word for it. A recent article in the British Medical Journal notes that claims and endorsements made on social media such as Facebook & Twitter are not regulated and may promote statements that have not been supported by science. Some red flags noted include:

  • Paid endorsers. Do you know that some comments and images about a product can come from people (celebrities and non-celebrities) paid by companies to post great reviews about their products? Be careful that such claims may be coming from a paid sponsor and may exaggerate their results from a product.
  • Endorsed hashtags. The hashtag such as “#ad” is a disclosure recommended by the Federal Trade Commission (FTC) to indicate that a social media post is coming from someone being paid (or otherwise reimbursed) by the company of the product they are endorsing. If such a hashtag appears in a social media post, then you know that it is sponsored and may be biased. (For more about FTC’s new endorsement guidelines, visit their FAQs web page.)
  • Biased research. Assessing the science behind claims is the best way to evaluate a product. However, a common practice is that companies cite their own labs and research. When it comes to dietary supplements, it’s best to get information about products from unbiased, evidence-based organizations such as Natural Medicines Comprehensive Database, United States Pharmacopeias (USP), or NSF International.
  • Unbalanced comments. When you scroll through a product’s social media page, do you find that all the reviews are positive? On platforms such as Facebook, companies have the ability to delete comments. A transparent company usually addresses negative comments and provides support to establish its position.

Look for these and other red flags when it comes to dietary supplements and their advertising. If you have a question about a particular sports product or dietary supplement and can’t find the answer on HPRC’s website, please use our “Ask The Expert” button located on the Operation Supplement Safety (OPSS) home page.

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