During those dog days of summer when the heat index reaches three digits, the value of an indoor exercise facility goes up. When you're trying to beat the heat, an indoor workout can be beneficial.

  When the heat index hovers above 100, outdoor athletes are much more susceptible to dehydration that, combined with an increase in body temperature, could lead to heat exhaustion and heat stroke. An indoor facility will enable you to exercise for longer periods of time and also get the adequate hydration that you need--six to eight ounces of fluid every 15 minutes during a hard workout.

  If the heat and humidity have scorched your motivation, try joining an exercise group. Check with local fitness clubs, your church or the nearest YMCA for a list of exercise classes. The structured schedule and camaraderie will help keep you coming back for more.

  Also, by bringing your workout inside, you can avoid exercising outdoors during peak, rush-hour traffic congestion. Breathing too much carbon monoxide from car fumes is harmful to your health. It is also best to avoid exercising outdoors when the ozone levels are high.  High ozone levels in the atmosphere can aggravate respiratory problems, such as asthma, and make it harder for you to breathe on your daily run or walk.

  Many people are concerned about safety and an indoor facility gives you more options for when you can work out. Concern about crime goes along with this point. If you worry about being outdoors alone at night, consider working out indoors among friends.

  An indoor facility also offers a wide variety of activities to give you cross-training benefits. At most facilities you can choose from aerobics, weight training equipment, the track, stationary equipment, racquetball, group sports and swimming. Also, exercise physiologists would be available to help you get the greatest cross-training effect from all of these activities.

  If you think of boredom when you think of working out indoors, try adding a little spice to your routine by using different video workouts. For example, try stretching exercises one day for a gentle workout, Pilates for an intense workout, or liven up your routine with a dance aerobics video that incorporates the latest Latin, or hip hop, moves. If you're skeptical about buying a workout video before trying them out, first rent them from a local video rental store to see if you like the exercise routines. An even more economical option would be to set up a temporary video exchange program with friends or coworkers.