The Dangers of Sun Exposure for Marathoners and Other Runners

Expose yourself at your own risk.

unners worry about training schedules, race performances, fueling, heart Rens and nagging injuries, and they follow elaborate schedules to reach long-term goals. Many runners, however, fail to think of protecting themselves from sun damage and skin cancer risks from cumulative sun exposure or blistering burns while training and racing. According to one study in the Archives of Dermatology (2006) of marathon runners and melanoma risk factors, 44 percent of the marathoners in the study did not use sunscreen regularly.

Endurance athletes such as marathoners and ultrarunners tend to spend many hours training in the sun through various seasons and conditions. Water, snow, and sand can reflect ultraviolet rays. Even on cloudy days, a significant amount of ultraviolet radiation penetrates the clouds. But sun protection is of utmost importance. Sun exposure is the single most preventable risk factor for skin cancer. Sun exposure also causes aging of the skin, resulting in wrinkles, skin laxity, and age spots. Sun damage to the eyes contributes to cataracts and macular degeneration.

Melanoma often develops as a result of excess sun exposure and sunburns. The use of tanning beds may contribute to the prevalence of melanoma, especially in young women. Malignant melanoma can be a devastating disease. In its early stages, melanoma may be cured with surgical removal, known as a wide local excision. This can result in significant scarring. When melanoma results in an invasive lesion, surgery to check for lymph-node involvement is often done. This may lead to a permanently swollen limb. Despite the best, most appropriate care, melanoma has the potential to spread widely to other areas of the skin, liver, lungs, lymph nodes, and brain, leading to death. Approximately one American dies

b> This melanoma has a large size, an irregular shape, and varied coloring and occurs on sun-damaged skin.

every hour from melanoma, and there will be an estimated 9,180 Americans deaths this year. The current lifetime risk in the United States is that one out of 52 people will develop an invasive melanoma and one out of 27 will develop any type of melanoma, according to Dr. Darrell Rigel (2012). Melanoma can even develop in children, often in conjunction with a birthmark. The risk of melanoma begins to increase at puberty. It is the most common form of cancer in young adults age 25 to 29, according to the American Academy of Dermatology (2012).

Marathon runners often show signs on their skin that are associated with an increased risk of melanoma. Notable runners who have suffered from melanoma include John J. Kelley, who died from metastatic melanoma, and Deena Kastor, who has reportedly had three early melanomas. A study published in the Archives of Dermatology (2006) found that marathon runners showed significantly more atypical nevi and solar lentigines (sun spots/age spots), as well as suspicious lesions requiring surgical removal, than age-matched controls. These changes are considered risk factors for the development of melanoma. The more hours spent training per week, the more striking the differences noted.

Besides sun exposure and genetic factors, it has also been suggested that intense training and competition may cause a decline in immune regulation. Any decrease in immune competence may result in an increased propensity for malignancy.

Risk factors for melanoma include

More than 50 moles, large or atypical moles

Light skin with red or blond hair, blue or green eyes

Family history of melanoma

Personal history of melanoma (higher risk for subsequent melanomas) History of sunburns

Tanning-bed use

Immunosuppressive therapy, such as medications used in transplant patients or for some patients with psoriasis or rheumatoid arthritis

Warning signs for melanoma include the so-called ABCDE rule:

Asymmetry: one half of the lesion is not a mirror image of the other half. Border is scalloped, irregular, or notched—not round or oval.

Color is not uniform across the lesion and may be dark brown or black. Shades of red, white, or gray may also be noted.

Diameter is often greater than 6 millimeters, or the size of a pencil eraser. Melanoma can start smaller as well, however.

Evolving or changing in size, shape, or color.

Other warnings may include the ugly duckling sign, which is a mole that looks very different from the other moles on the body—that is, it doesn’t fit the pattern of your other moles or is a new mole in an adult. Rarely, melanoma can be amelanotic—that is, lacking in melanin pigment so that it is predominantly pink or reddish in color. It is important to note that many times only one of these warning signs is present and perhaps to a lesser degree than photographs show.

There are other types of skin cancer besides melanoma. These include squamous cell carcinoma and basal cell carcinoma. These types of skin cancer are generally less dangerous and tend to occur in chronically sun-exposed skin. Squamous cell carcinoma has the potential to spread and become life threatening in some cases, particularly tumors that are large or that A This rapidly growing, pain. OCcur on mucosal surfaces such as the lips or in the ful keratotic nodule is a squa- Setting of immune suppression. Basal cell carcinoma mous cell carcinoma. can be very locally aggressive and invade deeply in

the skin, destroying normal skin structures. This can lead to unattractive scarring from surgical removal. Squamous cell carcinoma often looks like a painful, crusted growth or a hornlike lesion. Basal cell carcinoma can show up as a pink, scaly, or scarlike patch or a pimplelike lesion that doesn’t resolve promptly. It can also be an area of skin that bleeds easily with minor trauma.

So what is a runner to do?

Train at off peak hours whenever possible. The sun’s rays are most intense between 10:00 a.m. and 4:00 p.m.

A Regular use of sunscreen helps prevent skin cancer.

Wear a broad-spectrum sunscreen year-round, rain or shine. The new sunscreen labeling regulations from the FDA have been delayed until December 2012. Currently, SPF indicates the protection factor for UVB. The new labeling will clarify which sunscreens offer protection for both UVB and UVA. While UVB rays are responsible for sunburns, UVA rays penetrate more deeply into the skin and play arole in photo aging as well as skin-cancer induction. UVA can penetrate window glass, and there is a predilection for some skin cancers to occur on the left side of people who spend a lot of time driving. Sunscreen ingredients that are effective against UVA include Mexoryl, avobenzone, titanium dioxide, and zinc. Be sure to use a generous amount of sunscreen—about | ounce, or the size of a shot glass. Many people don’t use the recommended amount, and then the amount of sun protection is less than the SPF number indicates. Use of a high-number SPF sunscreen such as SPF 70 will provide protection even if used in smaller than recommended amounts, as recently reported in the Journal of the American Academy of Dermatology (2012). Reapply sunscreen whenever possible. Heavy perspiration can increase sun sensitivity.

Cover up with a hat, clothing such as a long-sleeve shirt, and sunglasses to protect the eyes.

All fabrics offer some degree of photo protection. Whenever possible, use clothing with built-in photo protection. Fabrics labeled UPF 15-50+ are sun protective.