If you want to get back into shape before the end of summer, then tennis is a awesome sport to learn.
As a sport tennis is fun and can be a fantastic way to get more physically fit in the spring. Tennis is best played outside on a sunny day and requires between 2 and 4 people to play. If you want to play the game properly you should have a tennis court, at least one racket, along with some tennis balls.
When playing you can choose to play by the rules or simply to rally and I find the best time to play is late afternoon as it is cooler outside. Like any other high energy exercise it is advisable if you to take copious amounts of fluids and also a light snack.
Shortly after deciding to pick up tennis I would recommend getting some tennis lessons to make the learning process easier. Taking lessons will make it easier to learn and the better you are the more fun the sport becomes. This sport is a great way to stay fit and is be a ton of fun.