As a player it is important that you work on your fitness before a tournament. If you're unfit not only will you give the opposition an advantage but you won't be able to enjoy playing as you'll soon get tired. There are lots of different types of fitness but for playing sevens your need to work on recovering quickly and maintaining explosive acceleration and top speeds for prolonged periods. I've outlined below a couple of sessions which will really help develop your fitness for playing sevens.
Remember to warm up and cool down to avoid injury.
If you have access to a gym this is a great way to develop your fitness for sevens. Choose an aerobic exercise maching: running, rowing or cycling machine. The key to this training is you've got to push yourself, so you could do this without the use of a gym, but note you should be exhausted when you fininsh:
Easy - Start with a minute cycling (or whichever activity you've chosen) at a slow steady pace with minimum resistance. Then as the minute ends increase the resistance to high and pedal as fast as you can for 30 seconds. Build up the number of times you can perform this exercise without a rest. First to 5 with a rest then to 10.
Medium - Start with a low resistance cycling at a steady pace for 30 seconds. As the 30 seconds runs out increase the resistance to high and cycle as fast as you can for 1 minute. Once the minute runs out reduce the resistancy and cycle at a slow constant pace. Again build up your fitness by increasing the number of times without a rest.
This is a very demanding exercise but gets great results if you carry out the sessions with maximum intensity. You will need to mark a distance of roughly 40 meters, so you can run shuttles of roughly 80 meters. Give yourself enough room either side to slow down. It's important you maintain a high intensity during your runs, don't progress to the next stage untill you can maintain a high pace through all the shuttles of the session.
Run at your maximum intensity throughout. If you try and pace yourself the object of the drill is lost and you won't gain the same result. Running to your marker and back counts as 1 shuttle. A total of 80 meters.
Easy - 10 shuttles 20 seconds rest, then 5 shuttles. You should not rest during shuttles keep going as fast as you can until you complete the set. Stick to the rest times, if you're still tired keep going as fast as you can.
Easy / Medium - 5 shuttles 10 seconds rest, 5 shuttles 20 seconds rest, 5 shuttles.
Medium / Hard - 10 shuttles 30 seconds rest, 5 shuttles 45 seconds rest, 5 shuttles 45 seconds rest, 5 shuttles 45 seconds rest, 3 shuttles 30 seconds rest, 3 shuttles.
Hard - 10 shuttles 30 seconds rest, 10 shuttles 45 seconds rest, 10 shuttles.