Strength Training
Workout 1:
- Back Squats or Safety Squat Bar Squats: 2x5, 1x10-20 (use a weight between 50 and 90% of what you used for 2x5)
- Bench Press or Incline Bench Press: 2x5, 1x10-20
- Deadlift: 2x5
- Rows: 3x10-20
Workout 2:
- Strict Overhead Press or Push Press: 3x5 superset with Rows: 3x5-10
- Front Squat: 3x3
- High Pull or Hang High Pull: 5x3
- Sit Ups: 3x10 superset with Hyperextensions: 3x10
Alternate between the above two workouts every time you train. Do strength training 3 non-consecutive days a week. Start with weights that are far too light, focus on technique, and when you get all the target reps with good form, reward yourself by adding 2.5kg to the bar.
Cardio
For cardio, pick an exercise (running, rowing, elliptical, cycling, kettlebell swings, burpees, thrusters, whatever) do 5 rounds of 1 min work 1 min recovery. The work should be hard enough that you need the break, but not so hard that you burn out before the minute is up. Do this at the end of each strength session.
On off-days, do light cardio by going for a half hour walk or a few 10-15min walks.
Food
Sort out your nutrition. Plenty of protein, a moderate amount of fat, carbohydrates mostly in the form of complex carbs rather than simple. Eat meat, eggs, nuts, dairy, fruit, whole grains and a lot of vegetables. If you're weight is changing too drastically and you're getting lots of fat and not a lot of muscle, scale back your intake a bit. If your weight isn't changing at all, probably increase your intake a little (it pays to be big for football, so I assume that losing weight isn't high on the agenda right now).