There aren't many gyms close to the downtown area. The only one we know of that offers day passes is the YMCA on Meadows Lane. But several locations are within a short cab or bus ride of the Strip. All offer day and week passes to non-members and are equipped with showers.
Here are some options:
Features free weights and an array of fitness equipment and cardiovascular machines, fitness classes, plus saunas, steam rooms, etc. Nearest locations to the Strip are at 3055 S. Valley View (702/368-1111) and 5035 W. Tropicana (702/876-2451), which also has a lap pool. A day pass is available to non-members for $15 or you can pay $50 for a full week. Towels are not available for rent, but can be purchased for $3.25. Note: If you have an out-of-town membership of the same level as the gym you wish to attend, the fee may be waived. Check in advance if you're unsure of what type of membership you have. Also, check the Web site, the local press, and the Yellow Pages for discount coupons. Open 24/7.
Sports and fitness center with racquetball courts, free weights, cardiovascular and fitness equipment, saunas, spa, steam room, and pool. Nearest Strip location is 5200 W. Sahara (702/364-5822). Day pass is $15 or $35 for a week, including complimentary towels. Open 24/7.
Specializes in body building, although also has a range of cardiovascular machines and fitness equipment. $15 for day pass, $35 for the week. Nearest location to the Strip is at 4720 W. Sahara (702/877-6966). Towels are available for $1/day. Open 24/7.
Facilities include racquetball and basketball courts, pool, and gym. Free to card-carrying members of other YMCAs or $15 for a day pass, including towel (no weekly passes available). Hours of operation are 6 am-10 pm Monday to Friday, 8 am-7 pm Saturday, and noon-5 pm on Sunday. Located at 4141 Meadows Lane (702/877-9622), this is the fitness venue nearest to the downtown area.