provide a good training surface with a medium to slow pace and consistent bounce. The Lawn Tennis Association prices the courts at between £34,000 and £60,000 to construct. Hard courts are typically made from asphalt or concrete with an acrylic covering. They are also called synthetic granular courts. These courts typically provide a "fast" game, which means the tennis ball will bounce with a low angle. The speed of the court can be changed by varying the amount of sand present in the covering. If a layer of cushioning material is added to a hard court then the performance increases and this is typical of an all-weather court. However, the cost of the cushioning can be substantial. An interesting problem with asphalt courts arises in very hot environments. The asphalt absorbs heat very quickly, but the painted lines will reflect the heat and this differential in temperature can lead to surface cracking. These courts are generally low-maintenance but they need to be recoated every 5 to 10 years. Most maintenance involves keeping the surface clean. There is generally little movement in the surface which means added strain on ankles and knee joints. The Lawn Tennis Association prices a porous macadam court at £20,000, which should last 10 to 12 years with low maintenance costs. An acrylic court would cost around £25,000 and is long lasting with low maintenance. "Fast/dry" courts are a relatively new innovation from America. These are generally made from basalt taken from the Blue Ridge Mountains of Virginia, which is then finely crushed and used as the top layer over either a purpose built sub-layer or just placed on top of an existing clay or asphalt surface. This type of surface is promoted as allowing more "sliding" by the players and therefore it helps to limit tennis injuries to the lower parts of the body. These courts are typically slower than grass. They can dry very quickly and do not have the heat reflection problems of clay courts. Porosity is low and often these courts have a slight slope to aid water run off. They are similar to the basic clay courts described above. Golf courses The growth in the popularity of golf, combined with the large sums of money invested in a golf course, has led to the development of turf management, which is a term used to refer to the skills of maintaining a golf