Like your muscles, hair that's strong looks better. Here's how to bring its bounce, resilience, and sexy back

To maintain your hair's strength, you need to work on it as you would your body. That means avoiding damaging vices, giving it the right nutrients, and committing to weekly conditioning sessions. The perfect strand of hair is built tough: The outer layer, known as the cuticle, protects the inner structural column, or the cortex. But over time, heat styling, sun exposure, and even shampoo can wear down the cuticle,exposing the center to damage. To rebuild your hair's va-va-oomph, take these fitness tests-meant to measure its elasticity, porosity, and volume-then adopt the strength-training moves that follow.

The Stretch Test

You want your hair to have the bounce of a slinky. Pluck a wet strand from your head and gently tug it at both ends. "If the hair stretches a bit before it snaps, it has good elasticity," says celebrity hairstylist Ron Williams, a national educator for Phyto Specific. If it breaks instantly, your hair is dehydrated and weak.

The most likely culprits: your blow-dryer, flatiron, or hair dye, says Charlene Deegen-Calello, the executive director of product development for Keranique. "All those aggressors can weaken the cuticle to the point that your hair loses its bounce."


Try to limit your love affair with hot tools to once a week, and apply a heat protector like StriVectin Hair UV Protecting Spray ($29, to damp strands before. Don't let your hot tool exceed 350 degrees (the middle heat setting on your blow-dryer is a safe bet). To help hair regain its armor plating, infuse strands with keratin, a key protein that keeps it strong. Find it in Schwarzkopf Essence Ultime Amber+ Oil Nutrition 60-Second Treatment ($8, drugstores), which also contains humectants for an extra hit of hydration. Swap it with your regular conditioner twice a week, focusing on the midshafts and ends to fight off fraying. And here's where a little heat won't hurt: After using the treatment, let your shower get really steamy for five to 10 minutes. "The heat helps lift the cuticle, which allows the moisturizing ingredients to penetrate better," Williams says

The Hydration Test

When your hair feels as dry as a burlap tote, it's lacking moisture and is more susceptible to damage. Remove a single strand of hair from your head and place it in a glass of water. If it floats for a few seconds, it's well moisturized. If it sinks immediately, it's too porous-which is either a natural trait of your strands or a result of the excess use of chemical procedures, like coloring and perming. "That means the cuticle has microscopic fractures that allow moisture to pass through the inner layer, like a sponge," Williams says. "That leads to dehydration, dullness, and frizz."


Products with heavy- hitting butters and oils such as shea and cocoa will lock in moisture; try Suave Professionals Moisture Mask with Almond + Shea Butter ($4, A protein-packed treatment like It's a 10 Miracle Repair Hair Mask ($37, can also fill gaps temporarily. Also, don't wash your hair more than you have to, says Jae-Manuel Cardenas, a stylist at Sally Hershberger salon in New York City: "Shampoos can contain harsh surfactants [the ingredients that give you a foamy lather] that strip hair of its natural oils, so sudsing up too often can weaken the cuticle." If your work- out schedule means you have to wash more often, add a protective preshampoo like Living Proof Timeless Pre-Shampoo Treatment ($26, to your routine. It acts as a sealant, forming a barrier over the cuticle to shield it from damage, Cardenas says.

The Volume Test

If you suspect that your strands are peacing out-leaving your formerly full head of hair either thin or brittle-there's a way to get to the root of the problem. Pull your hair into a ponytail. "If you can wrap the elastic band around three or more times, when it used to go around once or twice, your hair is probably growing in thinner," Williams says. Keeping track of your ponytail's density helps determine if you're shedding more than the average 80 to 100 strands a day, a consequence often linked to stress (which can trigger hormonal fluctuations that halt the hair-growth cycle) or a change in diet (which affects the production of protein in your body). Of course, age and genetics play a part as well.


If you've recently experienced a bout of intense stress-or are still in the throes of one-relax. As long as you chill ASAP, your hair should return to normal in a few months, Williams says. Additionally, make sure you're getting nutrients that promote hair-follicle growth, such as zinc, iron, and protein. Williams also suggests implement- ing a well-rounded supplement as a nutritional safeguard. Vitafusion Hair, Skin & Nails ($13, drugstores) contains biotin to boost the thick- ness of your hair, and vitamins C and E to maintain scalp health and strengthen strands from the inside out. And start using a scalp scrub to kick-start growth. Keranique Micro-Exfoliating Follicle Revitalizing Mask ($45, has gentle buffing beads that slough away excess oils and buildup that can block follicles, Deegen-Calello says. Massage it onto your scalp for two to three minutes after you shampoo, then rinse.