Physically, Mentally and Spiritually Strong

Moses was at least 80 years old when he received the 10 Commandments. Read here

Since he broke the first stone tablets out of anger (golden calf sight), he had to get back on the mountain to get a second pair. Can you imagine how strong he was!

Jesus was not the effeminate looking man that most images reveal Him as. He was a carpenter and carpenters in those days not only worked with wood, they worked with stones. They had no power tools of course so the wood had to be cut by using hand tools and great physical labor which must have took long, tedious hours to work with. The wood was not like what we see today; two by fours or four by sixes. They worked with large timbers of roughhewn wood. These timbers had to be cut down by hand and they had to be sawed down into workable sections. They had to be debarked and sanded. And carpenters in those days worked with stone more than they did wooden beams. And these stones were just not simple stepping stones or mortar bricks but more like boulders and these boulders had to be chiseled and cut down to size. 

Every bit of the carpenters work was extremely labor intensive and so we should realize that Jesus had to have been a big, strong man with great physical strength, yet He kept this strength under control in what is a good description of meekness: Strength under control. So we see that Jesus was a man's man and may have had the body of a heavy construction worker. He must have been an imposing physical specimen. (<well noticed by Jack Wellman)

It's not likely that he had long hair either.

1 Corinthians 6:19 Your body is a temple of the Holy Spirit within you

A word on Gluttony

Philippians 3:19 Their end is destruction, their god is their belly, and they glory in their shame, with minds set on earthly things.
1 Corinthians 6:19-20 Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body.

Treating your body as a dumpster is disrespectful to God and yourself. Do not be a lazy sluggard (Proverbs 13:4) nor hypocrite by criticizing others (Matthew 7:3) because you think your sin is smaller.

Become a professional. You can join the legion directly, or enter the army first. Every male should encourage the younger generation to join because 

Martial Arts versus Gym selfies! 

It's about responsibility and awareness. Boards don't hit back - Bruce

"It is better to be a warrior in a garden than a gardener in a war" - Sun Tzu

Train the best you can,

use the facilities you can.

Shaolin Monks
do not
eat meat.....

Fasting and Eating Healthy

Your body is the temple of your soul, not a garbagecan. 
Fasting is not only recommended for spiritual effect but also because it is very healthy for the body. Real fasting: not eating after a few hours and then fast again. That is not fasting.

1 Corinthians 6:19 Do you not know that your body is the temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? 

Healthy food: did you know that John Harvey Kellogg, yes, from the corn flakes, was a christian and a vegetarian? In 1863 James Jackson, a christian as well,  invented granula, for a while only, ready-to-eat grain-based breakfast product. Did you know that the founder of Quaker Oats.. was also a christian? His name is Henry Parsons Crowell.

Additional tip: there are huge benefits to add yoga or pilates to your work out. 

Recommended Literature

The Art of War by Sun Tzu

The Thirty-six Strategies Of Ancient China by Stefan H. Verstappen

Strategic Weapons of Our Warfare by Elsie Clark

The Book of Five Rings by Miyamoto Musashi

Wen-tzu by Lao Tzu. Translated by Thomas Cleary

1984 by George Orwell

On War by General Carl Von Clausewitz

Hagakure by Yamamoto Tsunetomo

Animal Farm by George Orwell

Luke 11:21 When a strong man, fully armed, guards his own house, his possessions are safe.

Self defense, look and learn 

hard2hurt is a good youtube channel, recommend.
It reminds me of a few cases in which I did not send or suggest something to carry, because I knew the ones were not able to use it properly and it would instead helping them make them even a bigger victim because of it. 
Be serious about your safety and those around you. If you are a bloke you have more opportunities like joining the legion because your body is made for this shit.