Gone are the days of accepting hotel guest rooms filled with smoke, germy surfaces and stagnant air. With personalization becoming a growing trend in all aspects of travel – from bespoke experiences to custom drinks to localized rooms – it's no surprise that consumers expect the same when it comes to health and wellness. Not only are guests seeking innovative spa treatments and fitness classes on vacation, they're also expecting wellness to be part of the entire experience – and something they can tailor to their liking.According to Dina Belon, western regional director for Paladino and Company, a green building consulting firm, wellness features not only benefit the guest but the property, as they increase loyalty and positive reviews. "It wasn't long ago that wellness amenities were only expected at high end exclusive hotels, but now we are finding a variety of hotel brands providing health and wellness elements," she says.[See: 10 Top Wellness Retreats Around the Globe.]A Holistic ApproachThere is perhaps no better example of a hotel chain that has embraced wellness from top to bottom than EVEN Hotels, a new brand from InterContinental Hotel Group, including the popular EVEN Hotels New York Times Square South. All EVEN rooms feature a fitness area with a stability ball, yoga mat and block, strength bands, standing desks and fitness videos on demand. "The brand was designed to offer a consistent, holistic wellness experience to meet the needs of our target wellness-minded traveler, and unlike other hotel brands whose health and wellness programs offer limited or add-on services, all EVEN properties are built solely with the wellness of our guests in mind," says Heather Balsley, SVP, Americas Brand Management, IHG. Jim Kaese, CEO of Athletic-Minded Traveler who consulted with IHG on the creation of EVEN, explains that the hotel's "core is wellness so everything flows and fits from the athletic studio to the staff training." According to Kaese, "The hotel is not comprised of a patchwork of amenities that whimsically change with the latest fad."Wellness-Themed RoomsWhile most hotels have not centered their amenities entirely around health- and wellness-focused amenities and services, many are beginning to offer select rooms with a healthy theme, including fitness and exercise. Hilton, for example, is currently testing fitness rooms at Hilton McLean Tysons Corner with options for a spin room with spin bike, a cardio room and a yoga room. Similarly, select Westin properties, like The Westin Peachtree Plaza, Atlanta, offer WestinWORKOUT rooms with a treadmill or stationary bike, weights, fitness DVDs, resistance bands and stability balls, while Switzerland's Kameha Grand Zurich lets guests choose between a workout suite with exercise equipment and ping pong table or the serenity suite with yoga mat, bands and books.Other hotels are offering wellness rooms and suites, which offer space for spa treatments, aromatherapy and room for meditation with access to special concierges and wellness experts. The Sanctuary Camelback Mountain Resort & Spa has an entire area called the Spa House that can accommodate groups of up to 16 looking for a spa getaway.Meanwhile, the company Delos has developed the Stay Well room, which has been implemented at several properties, including the MGM Grand Hotel & Casino in Las Vegas and the Atlanta Marriott Marquis. These rooms promote the healthiest environments possible with features designed to reduce stress, increase energy, optimize digestion and promote better sleep. At the MGM Grand, which has 171 of the rooms available, you'll find water infused with Vitamin C in the shower, protection from electromagnetic fields and blackout shades. Plus, Belon says that MGM Grand's Stay Well rooms have a higher than average occupancy rate despite costing an extra $30 a night. [See: 10 Under-the-Radar Spa Retreats.]Healthy AmenitiesIn addition to standard lotions, pens and minibars, hotels are adding good-for-the-body amenities as well. Kimpton, for example, has rooms outfitted with yoga mats in the closet, as well as free on-demand yoga and Pilates channels on the TV. Kimpton properties even roll out fresh towels, flavored water and energizing snacks as an extra service.Other properties are also providing free exercise classes streamed via in-room TVs. Try Xtend Barre, a combination barre and Pilates workout at The London NYC or The Barre Code at the Hyatt Regency Chicago. When you book a stay at the Taconic, a Kimpton Hotel, in Manchester, Vermont, which is set in the Green Mountains, you'll find a hiking stick for inspiration to get active. And because so many guests travel with their bikes to Portland, the Portland Marriott Downtown Waterfront has rooms that come with bike storage. Meanwhile, the Benjamin in New York, which is focused on helping guests get quality sleep, has 10 pillow options, 200-calorie bedtime snacks for a fee and a pre-bedtime call to remind you to power off electronics. Even minibars are getting in on the wellness trend with healthier options. At the Bulgari Hotel London, you can expect minibars stocked with protein bars, fruit and shakes, and at The Epiphany Hotel in Palo Alto, California, you can enjoy seasonal salads, trail mixes and more (for an additional charge).Lighting and Air QualityIt seems even lighting and the quality of the air in a hotel room, while not as obvious, can have an impact on a guest's stay. "I recently visited a LEED-certified hotel and another guest said 'I don't know why, but I just really feel great in this hotel.' That is indoor air quality!" says Belon. "If you've ever stayed at a hotel and come home sick from allergies, then you were probably staying at a hotel that didn't address air quality."Companies like View Dynamic Glass are working with hotels, including Hilton Los Angeles/ Universal City to incorporate "smart" glass with windows that tint on demand based on weather conditions, making blinds and shades unnecessary and also reducing heat and glare. Special lighting at Miraval Arizona Resort & Spa in Tucson, Arizona, significantly reduces blue light that can impact sleep quality. Stay Well(R) rooms at the MGM Grand Hotel & Casino offer "wake-up light therapy," which exposes guests to short periods of blue-shaded lighting to both increase energy and help reduce the effects of jetlag, along with LED nightlights that provide light without disturbing melatonin levels. Upon Request Many hotels, including Fairmont, Omni and Westin, loan guests fitness items such as sneakers, iPods, workout clothes and yoga mats for free or at a minimal cost. At the Sheraton Puerto Rico Hotel & Casino, you can order an in-room stationary bike. And the Conrad Chicago, opening this summer, is happy to deliver a stability ball for guests to use at the in-room desk or give you a "fitness wake-up call" in the morning with a special motivational message.[See: The 50 Best Hotels in the USA 2016.]On the HorizonSo what else is in the works for wellness-seeking guests? Kevin Carl, global managing director of Digital at Accenture Travel, says personalization will continue to drive the trend with options such as collaborative hotel room workouts and smart thermostats controlled by guests.