Most of us have heard of "puppy fat" but in general body fat composition can be controlled relatively early in life. For example, there are many sports events where young sportspersons at the start of their professional careers have already attained, more or less, their ideal body fat and protein ratios (e.g. football players, track athletes, cyclists, to name a few).
Young tennis players in general do not fall into this category. They seem to get healthier and less chubbier with time—this apparently after they "discover" the correct training regime that truly gives them their optimal fitness that in turn allows them to produce optimal performances consistently on the tennis court. Andy Murray is an example of someone who belated optimized his fitness levels. Andre Agassi is another and Serena Williams' muscle definition has certainly matured along with her career.
If Laura Robson is to become a Top Ten female tennis player (she's just this minute reached the last 16 of Wimbledon) and fulfill her Grand Slam potential, it is clear her health and fitness levels will need to improve.
Taking a look at the British tennis players who did not progress beyond Wimbledon's first round (e.g. James Ward, Tara Moore, Johanna Konta, Elena Baltacha, Anne Keothavong, Kyle Edmund and Samantha Murray), I would hazard an educated guess that their fitness are not optimal. For instance, Elena Baltacha has always been chubby and has not made much progress in her years as a journeywoman tennis pro. This is a fate that Laura Robson should avoid.
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