What you’re experiencing is called a vasovagal response, a reflex that occurs when your body overreacts to certain triggers, like blood or needles. The triggers stimulate a nerve that then causes your heart rate to slow down and your blood pressure to drop. As a result, you may suddenly feel warm or light-headed, turn pale, or lose consciousness.

To get through a blood draw when you feel dizziness coming on, try the applied tension technique: Tense the muscles in your body for 10 to 15 seconds, then release for 20 to 30 seconds, and continue. This helps raise your blood pressure, making you less likely to faint. Ask to lie down, too—then look away so you can’t see the needle entering your arm or the blood flowing.

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It’s not entirely understood why some folks have vasovagal responses and others don’t. The reassuring news is that these spells are usually harmless—and you shouldn’t need treatment if they happen sporadically and aren’t interfering with your quality of life. But if your reaction is constant and so bad that you dread getting immunizations, medical tests, or surgeries, you should consider seeing a psychologist who can help you work through your fear using exposure therapy (in which you practice being in the presence of needles until you’re desensitized to them).

Got 20 minutes? Then you have just enough time to hop on the treadmill for this high-intensity interval (HIIT) workout from Debora Warner, a running coach and CEO of the Mile High Run Club.

Warner calls it a "Peak to Peak" workout, since it alternates between challenging bursts of effort and lighter recovery periods. It also combines two types of interval training—hills and speed—to deliver a high-intensity sweat session in less time. As you probably already know, intervals are an efficient way for runners to build strength. Not only do they burn more calories than running at a steady pace, but they also help improve speed and stamina.

"All runners do interval and speed training or hill work to improve performance," Warner explained in a recent Facebook Live with Health at Mile High Run Club's New York City studio. "It's the only way to get faster and improve indurance." (Check out the full video below.)

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Ready to break a sweat? The first 10 minutes of Warner's Peak to Peak workout are comprised of hill intervals, which fire up your glutes and build strength. The final 10 minutes are speed intervals, helping you to push your pace.

Before you get started, pay attention to your form: Warner recommends that you "run tall," which means keeping your chest and ribcage out and open, and making sure your shoulders are relaxed. Your arms should be kept at a 90-degree angle, with your wrists and elbows in line.

The age-old idea that you can shrink your pores—using anything from a splash of ice-cold water to an egg-white mask—is a fantastic one. Sadly, it’s also a fantasy: “Pore size is genetically determined,” says Debra Jaliman, a dermatologist in New York City, and you can’t make pores physically smaller. So to a certain extent, you have to accept what you were given. But there are things you can do to minimize the appearance of your pores.

Pores: A Primer

Those tiny dots you see on the surface of your skin are actually the openings of hair follicles. Each one contains a sebaceous gland, which produces your skin’s oils. (Pores are more noticeable on parts of the face, like the forehead and the nose, where the sebaceous glands are bigger.) The size of your pores depends primarily on your genes. Typically, says Jaliman, fair-skinned people have pores on the small side; those with olive or darker skin have larger pores. Your skin type, too, can play a role. Naturally dry skin tends to appear poreless, while oily skin often has more-visible pores.

Several other factors can affect pore size. Dead skin cells and trapped sebum—which, put together, form a pimple—can stretch out pores. UV rays weaken the collagen that supports pores and keeps them tight, so they can also make pores look bigger. Similarly, the collagen loss that comes naturally with aging can increase the appearance of pore size. And picking at or squeezing a pimple can cause trauma to the skin, which may permanently widen the pore.

Easy Pore-Minimizing Strategies

The key to making pores appear smaller is to keep them clear. During the day, stick with noncomedogenic moisturizers and makeup; avoid products that contain heavy ingredients, like petrolatum and mineral oil, both of which may irritate pores and make them look bigger. Always wash your face with a gentle cleanser before bed to prevent the day’s dirt and makeup from clogging pores, says Heidi Waldorf, a dermatologist in New York City. (For product suggestions, see below.) Cleanse before and after working out, since sweat can carry cosmetics and debris to pore openings, where they’ll settle in and stretch the skin. When you cleanse, consider doing it with a power brush, such as the Clarisonic MIA Skin Cleansing System ($99, sephora.com). The company’s research shows that its system is more than twice as effective as using your hands to wash your skin.

Exfoliating is also crucial, since it removes pore-enlarging dead cells from the skin’s surface, says Jaliman. Exfoliate daily if your skin is hardy and doesn’t get red, one to three times a week if your skin is sensitive. Choose an over-the-counter gel, mask, or lotion that contains a proven sloughing ingredient, such as alpha hydroxy acids, retinol, or fruit enzymes. If in addition to having large pores, you tend to break out, choose a lotion with salicylic acid instead, says Patricia Farris, a dermatologist in Metairie, Louisiana…