Post-tensioned concrete is reinforced with a grid of high-strength sheathed steel tendons, or cables. While the concrete is curing, the cables are tensioned in both directions and held permanently under stress by anchoring them in a perimeter beam. This squeezing action keeps the concrete in compression, improving its tensile (or bending) strength. The more the concrete is squeezed together, the less likely it is that shrinkage cracks will develop or open. (See a more complete description of post-tensioning from the Post-Tensioning Institute.)
We specialize in adult tennis lessons for young professionals in their 20's and 30s living in Miami.  We have the complete pathway for adults who want to learn tennis and meet new friends including: Novice, Intermediate and Advanced level programs. See Our Class Schedule Here: Our classes also feature a social component to our lesson series and included in your purchase as we head out for drinks after class.   Players who join our classes also get on our email newsletter which offers things to do and place to play in and around the Miami tennis community. Get ready to imm ... View Profile
Finally, choosing the right equipment is essential as you learn to play tennis. Proper grip size avoids pain. To measure the correct grip size, hold your racket hand out palm side up, and measure from the crease of the ring finger to the tip of the ring finger. This should be the measurement around your racket handle, generally about four inches in diameter.
The rackets from the Wilson Ultra series are processed in the graphite frame construction with carbon fiber, so that a power-loaded playing feeling is created. The oversize head provides good spin characteristics and the power of the club can be controlled very well via the spin. A comfortable racquet handling and a special parallel drilling technology (the strings dampen more vibrations) provide comfort.
In the early 1980s, "graphite" (carbon fibre) composites were introduced, and other materials were added to the composite, including ceramics, glass fibre, boron, and titanium. Some of the earliest models typically had 20% or more fiberglass, to make them more flexible. Stiff rackets were typically not preferred by most players because of their familiarity with the comfortable softness of wood. These early models tended to be very flexible and not very powerful, although they were a power upgrade over wood and metal rackets. Wilson created the Jack Kramer Pro Staff, the graphite version of the wood racket of the same name extremely popular in the late 70's and early 80's. This was the origin of the extremely influential Wilson Pro Staff 85. Chris Evert's first graphite racket was this Jack Kramer version, which had 20% fiberglass. It was not a market success and she, along with everyone else, quickly replaced it with the stiffer Pro Staff 85, which had 20% kevlar. It used the same mold and had the same braided graphite, but offered a very noticeable improvement in power. The very popular Prince original graphite, an oversize in its most popular form, was also quite influential and used by many pros, especially as juniors. Jennifer Capriati and Monica Seles, for instance, used the Prince graphite to contest their influential Wimbledon match in 1991 that has often been hailed as the beginning of the power baselining game in the WTA, although that claim is somewhat hyperbolic and is, in large part, due to the mistaken impression that the players were hitting much harder when, in fact, the rackets were more powerful. However, the very large head size, when compared with the midsize and, especially, the old "standard" size, made it easier to produce power. The racket also had an open string pattern. The Prince "original" graphite name is rather a misnomer, as it went through some significant design adjustments over its lifetime. For instance, the truly original model had a reverse teardrop head shape, something no subsequent versions had. Stiffer composite rackets, when compared with the first and second generations of graphite composites, are the contemporary standard. The last wooden racket appearing at Wimbledon appeared in 1987, long after they were abandoned by practically all professionals.[17] Borg tried to stage a comeback with his standard wood racket, after his premature retirement, but it quickly ended in failure, as the standard wood was no match when placed against a stiff midplus graphite. It is also commonly argued that Chris Evert would have been able to beat Martina Navratilova during the latter's most dominant period if she had switched from her wood racket years sooner. Additionally, the last influential wooden racket, the Prince Woodie, had layers of graphite to increase its stiffness and was an oversize. It was used by Tommy Haas, Gabriela Sabatini, and quite a few others. It offered very little power but did offer much more surface area than a standard-size wooden frame. Sabatini found it helpful, as compared with smaller rackets, due to her production of heavy topspin. The only woman to beat Martina Navratilova in 1984, Kathleen Horvath, used the Prince Woodie, one of only six losses Navratilova suffered in a three-year stretch involving 260 matches.[18]
The player who would normally be serving after 6–6 is the one to serve first in the tiebreak, and the tiebreak is considered a service game for this player. The server begins his or her service from the deuce court and serves one point. After the first point, the serve changes to the first server's opponent. Each player then serves two consecutive points for the remainder of the tiebreak. The first of each two-point sequence starts from the server's advantage court and the second starts from the deuce court. In this way, the sum of the scores is even when the server serves from the deuce court. After every six points, the players switch ends of the court; note that the side-changes during the tiebreak will occur in the middle of a server's two-point sequence. At the end of the tiebreak, the players switch ends of the court again, since the set score is always odd (13 games).

The tennis scoring system is a way to keep track of tennis matches (including pick-up games). Some tennis matches are played as part of a tournament. (Tournaments may have various categories, such as singles and doubles.) The great majority are organised as a single-elimination tournament, with competitors being eliminated after a single loss, and the overall winner being the last competitor without a loss. Optimally, such tournaments have a number of competitors equal to a power of two in order to fully fill out a single elimination bracket. In many professional and top-level amateur events, the brackets are seeded according to a recognised ranking system, in order to keep the best players in the field from facing each other until as late in the tournament as possible; additionally, if byes are necessary because of a less-than-full bracket, those byes in the first round are usually given to the highest-seeded competitors.
Head size plays a very key role in a racket's performance characteristics. A larger head size very generally means more power and a larger "sweet spot". This is an area in the string bed that is partially more forgiving on off-center hits and which produces more ball-reflective power from string deformation, known as the trampoline effect. However, large head sizes can increase twisting, which makes off-center hits more difficult to control and can reduce a player's overall power production due to the playing compensating for the extra inherent power, typically with stiffer strings to reduce the increased string deformation of large heads. A smaller head size generally offers more control for many shots, particularly the service and groundstrokes aimed near the lines, but can lead to more shanks (wild misses, from hitting the frame or missing the sweet spot). This drawback is most common for professional players using single-handed topspin backhands, as well as for recreational and aged players at net. Shanking due to small racket head size is typically exacerbated by racket weight, which slows the reaction time, as well as, to a lesser degree, the racket's balance point. In professional tennis, currently-used racket head sizes vary between 95–115 square inches (610–740 cm2), with most players adopting one from 98–108 square inches (630–700 cm2). Rackets with smaller and larger head sizes, 85 and 120–137 square inches (550 and 770–880 cm2), are still produced but are not used by professionals currently. A very small number of professionals, such as Monica Seles, used 125 square inches (810 cm2) rackets during some point in their careers. Rackets with smaller heads than 85 square inches (550 cm2) have not been in production since the 1980s and rackets with larger head sizes than 137 square inches (880 cm2) are not currently legal for the sport, even though only elderly players typically choose to use rackets beyond 115 square inches (740 cm2) and it is nearly unheard-of for a serious player who is not elderly to choose a racket over 125 square inches (810 cm2). The WEED company, founded by Tad Weed, specializes in producing very large rackets, primarily for the elderly market. Rackets that are moderately higher in power production, moderately lower in weight, moderately larger in size, and which typically possess a slightly head-heavy balance are often called "tweener rackets."[11] Rackets that have the smallest heads in current use, the highest weights in current use, and headlight or even balance are referred to as "players' rackets". Oversize rackets, typically 110 square inches (710 cm2) in size, were once pejoratively referred to as "granny sticks" but resistance to them being seen as illegitimate rackets for younger players decreased dramatically with the successful use of these rackets by a small number professionals such as Andre Agassi and Pam Shriver. Originally, even midsize frames (85 square inches (550 cm2)) were considered jumbo, and some top players, such as Martina Navratilova and Rod Laver said they should be banned for making the sport too easy. Later, these same professionals, including John McEnroe, signed a letter supporting a switch back to wood frames, or a limitation to the original standard size of approximately 65 square inches (420 cm2). Perhaps the last professional to use a standard-size racket in professional tennis was Aaron Krickstein, known for the strongly-contested match against Connors at the 1991 US Open. He used a Wilson Ultra-II standard-size graphite racket also used in the 1980s by the hard-hitting teen Andrea Jaeger. The first oversize, the fiberglass Bentley Fortissimo from Germany, was praised by racket designers but was considered too large to be taken seriously by the small number of players who were exposed to it.

Wheelchair tennis can be played by able-bodied players as well as people who require a wheelchair for mobility. An extra bounce is permitted. This rule makes it possible to have mixed wheelchair and able-bodied matches. It is possible for a doubles team to consist of a wheelchair player and an able-bodied player (referred to as "one-up, one-down"), or for a wheelchair player to play against an able-bodied player. In such cases, the extra bounce is permitted for the wheelchair users only.

Picking a good one usually depends on your play style. Heavier rackets are slower, but give you more power. Lighter rackets offer maneuverability, but you won’t be able to hit a grand slam. Smaller racket heads concentrate power while larger ones help newer players get a hold of the ball. If you play at the net, you need something light, fast, and large, while baseliners need heavier rackets that give them power and help them drop spin on the ball. You must find the right mix of power and precision to suit your personality. To help you, here is our 7 best tennis rackets.

We’ve now covered scoring, the first step to learn as a tennis beginner — let’s move on to understanding the court. A tennis court is 78 feet long by 27 feet wide, and divided in half length-wise by the net. At each end of the court, there are white baselines — here, the serves are taken. These are also the out-of-bounds lines — a ball must not bounce beyond them or it’s out and the player who hit the ball loses a point.
Best for Beginners: All right, most beginners aren’t going to want to drop $200 on a racket, but if you want something that is very forgiving no matter what type of player you are or what type of player you want to become. The overall feel is very plush, though it bears a deceptively high stiffness rating. It’s friendly with spin and minimizes how many of your shots go rogue over the fence. It allows you to move from power hitting to finesse games with ease and gives you a chance to find what feels best without pressuring you in one direction or another. Especially kind to off-center hits the 99.5 square-inch head gives you plenty of real estate for while the 11.3 oz weight makes it good for quickdraws. [Purchase: $190]

The ITF's Play and Stay campaign promotes playing on smaller courts with slower red, orange and green balls for younger children. This gives children more time and control so they can serve, rally, and score from the first lesson on courts that are sized to fit their bodies. The ITF has mandated that official competition for children under 10 years of age should be played on "Orange" courts 18 m (59 ft) long by 6.4 m (21 ft) wide. Competition for children under 8 years is played on "Red" courts that are 11 m (36 ft) long and 5.5 m (18 ft) wide. The net is always 0.8 m high in the center.[4]
You don’t need a lot to begin playing tennis. You just need a racquet and some gym clothes including proper shoes. Any set of gym clothes will work for tennis, so you don’t necessarily need to spend a lot of money. Tennis requires a good amount of footwork, however, so you’ll need to make sure you have a decent pair of tennis shoes. Avoid running shoes as they do not provide the ankle support you’ll need for rapid lateral movement.
The head-light balance point is rarer in professional tennis than it once was, as the sport has converted to larger-headed rackets, stiffer rackets, stiffer strings, more western grips and accompanying stroke production, and more topspin. The head-light balance point is most optimal for the serve and volley style with a continental grip. Serve and volley is no longer a viable option for nearly all professionals as the mode of playing for most points in a match. Head-heavy rackets became popular, mainly with recreational players, primarily with the introduction of the Wilson ProFile widebody racket. The head-light balance makes volleys and serves easier to produce, while groundstrokes are less stable. The head-heavy balance makes groundstrokes more stable, which typically increases the player's comfort for swinging harder to add power, but makes serves and volleys more cumbersome. A head-heavy balance also puts more stress on the elbow and shoulder.[12]
In the US, "Tennis Court" was released as a 7-inch vinyl single on 27 August 2013.[14] Lava and Republic Records initially planned to service "Tennis Court" to US modern rock radio on 11 March 2014 and contemporary hit radio (CHR) on 8 April 2014 as the album's third US airplay single, following "Royals" and "Team".[15] Republic cancelled the scheduled release in favour of "Glory and Gore", which impacted modern rock radio on 11 March.[16][17] The label also planned to service "Glory and Gore" to CHR, but subsequently called of its release and serviced "Tennis Court" to CHR as originally planned.[18] "Tennis Court" ultimately impacted hot adult contemporary radio and CHR on 21 and 22 April 2014, respectively.[19][20] It was released to UK radio on 12 May 2014.[21]
There is a wide variety of racket designs, although the badminton racket size and shape are limited by the Laws. Different rackets have playing characteristics that appeal to different players. The traditional oval head shape is still available, but an isometric head shape is increasingly common in new rackets. Various companies have emerged but Yonex of Japan and Li-Ning of China are the dominant players in the market. The majority of top tournaments are sponsored by these companies. Every year new technology is introduced by these companies but predominantly, all rackets are made of carbon graphite composite.
The origin of the use of "love" for zero is also disputed. The most likely explanation is that it derives from the French expression for "the egg" (l'œuf) because an egg looks like the number zero.[8][9] This is similar to the origin of the term "duck" in cricket, supposedly from "duck's egg", referring to a batsman who has been called out without scoring a run. One possibility comes from the Dutch expression iets voor lof doen, which means to do something for praise, implying no monetary stakes.[10] Another theory on the origins of the use of "love" comes from the notion that, at the start of any match, when scores are at zero, players still have "love for each other".[11]
I have been teaching Tennis for over 30 years.Started playing from I was 11 years old in Jamaica, at 13 was under 14 & 16 Champion, was Junior Caribbean Open Champion. Competed in Orange Bowl in 1972 Competed in Junior Wimbledon in 1973 Won the Edgar Redwin Sportsmanship Award over several years. Youngest Ever All Jamaica Ladies Open Champion at 15. Also won Caribbean Ladies Open Champion in Singles, Doubles & Mixed Doubles. Was Coached by Harry Hopman ,traveled extensively on The WTA Tour competing on the "Avon Circuit," in the " French, Wimbledon & US Open Grand Slam Events." Played U.S. Clay Courts as well as Open events in Hong K ... View Profile

Although Kolkmann admits that concrete courts cost substantially more initially than asphalt, an asphalt surface often requires more frequent and costly upkeep over its lifespan to repair cracking and settling. "Through our own recordkeeping, we estimate that an asphalt court will be unavailable for play, due to repairs being made, for about 100 days over a 20-year period," he says. "During this same time, a post-tensioned slab would be down for about 20 days. In our climate in the upper Midwest, repairs can only be done in the summer, when everyone wants to play. For a private court, the downtime may not be as crucial. But for a club, it can be a substantial unknown cost in lost revenue."
Throughout most of lawn tennis' history, most rackets were made of laminated wood, with heads of around 65 square inches (420 cm2). A small number of them were made of metal, such as a 1920s racket by Dayton.[15] Some, rarely, also had metal strings. In the late 1960s, Wilson popularized the T-2000 steel racket with wire wound around the frame to make string loops, after having purchased the design from René Lacoste, who produced the racket first in a more limited run. It was popularized by the top American player Jimmy Connors and was also, prior to Connors using it, by Billie Jean King in her early career. Many players said it lacked control but had more power, when compared with wood frames of the period. Connors used the rarer "firm" model that had additional throat welds to increase its stiffness. In 1968 Spalding launched an aluminum racket, called The Smasher. Aluminum, though lighter and more flexible than steel, was sometimes less accurate than wood. The biggest complaint, however, was that metal rackets caused strong cases of tennis elbow, especially the kind that had holes for the strings directly in the frame, rather than using an external wire wrapper, as in the T-2000. Because of that drawback in particular, most of the top players still preferred to use wooden frames.[16]
Play all your practice games in sets. Tennis is played in sets--you don’t just play one game and then go home! Sets consist of at least six games. The set doesn’t end until one player wins six games and has a margin of two wins over their opponent. For example, if one player has won six games and the other has won five, they’ll have to keep playing until the winner has two more wins than the loser.[6]
Tennis is played on a rectangular, flat surface. The court is 78 feet (23.77 m) long, and 27 feet (8.2 m) wide for singles matches and 36 ft (11 m) for doubles matches.[48] Additional clear space around the court is required in order for players to reach overrun balls. A net is stretched across the full width of the court, parallel with the baselines, dividing it into two equal ends. It is held up by either a metal cable or cord that can be no more than 0.8 cm (1⁄3 in).[49] The net is 3 feet 6 inches (1.07 m) high at the posts and 3 feet (0.91 m) high in the center.[48] The net posts are 3 feet (0.91 m) outside the doubles court on each side or, for a singles net, 3 feet (0.91 m) outside the singles court on each side.