How do I get a strong body like a soldier in the best ways?
Every time I have let myself go a little bit too much and want to get back into shape, I do the following:
Running, especially trail running. You don't have to run fast. More important than your time is your distance. Run as much as you can. The more, the better.
Cutting back on the beers (mainly to lose weight which is 50% of getting fit). In your case, it might be eating less sugar or junk food.
In the gym. As you can see, I’m training with really light weights (but do more reps).
Going to sleep early. You can't train when you're tired, and unlike in the army, there's nobody screaming at you to give you “motivation”.
Hitting the gym. Be careful here, don't overdo it! If you train too much, you'll soon become tired and unmotivated. I would recommend training with relatively light weights but doing more reps without a lot of breaks (high-intensity training). Half an hour three times a week is enough for the beginning.
Try this for three weeks. More important than having a “tough” fitness routine (like we see so often in all these stupid “get fit in X days” tutorials) is to stay motivated and follow a training plan that is doable and simple