Have a strict routine
Whether you are inspired by a cricketer or want to take up the sport professionally, you will need to come up with a proper routine and work out according to a strict plan in order to attain the level of fitness required. Some people are lucky enough to have the services of professional trainers, and if you can afford one, you should look seriously consider it.
Train according to your specialty
In the current era, cricket has become extremely scientific and methodical. You cannot just keep working hard without knowing your strengths and weaknesses. You must train according to your specialty and should look to develop muscles which come into play in your specific role.
For example, a batsman needs to have strong forearms and wrists; whereas, a fast bowler needs immensely strong legs, shoulders and arms. Similarly, a wicketkeeper should work extremely hard to strengthen his back because he has to sit and stand countless times in a match. Different exercises are required for different roles in the game. However, a fast bowler has to work harder as compared to other players.
When you hit the gym, you need to remember that you are training for a sport and not a body building competition. You should strengthen your muscles and shape them using light weights. Hitting the gym about three days a week is advisable.
If you are a bowler, avoid exercises which expand your torso. If you start bulking up, you will have issues bowling with a high-arm action.
Running & Stretching
You should gradually increase your laps while jogging. Sprints and shuttles are also very important to improve your agility. In order to avoid pulling a muscle, you must stretch and warm-up before and after workouts.
Your diet should include carbohydrates, vitamins, minerals and other sources of energy. Milk, fruits, wheat, eggs and meat should be a regular part of your diet, especially if you are a fast bowler.