Welcome back to Get Fit Guy. I'm your host, Dr. Jonathan Sue. Every week, I'll share

science-backed tips to help you get fit, stay fit, and optimize performance. In my early 20s,

I had a goal of putting on as much muscle mass as humanly possible.

At the time, I was a corporal in the Marine Corps, getting ready for a six-month deployment on a

Navy warship, and I had the perfect plan, bring 180 cans of tuna fish,

180 packets of protein powder,

and lift weights in the ship's gym twice a day.

I'm guessing most of my listeners haven't been on a deployment like this before.

This was a peacetime deployment in early 2001, before 9-11.

There's not much to do except eat, sleep, exercise, and play poker.

I wasn't much of a poker player and had to do something to kill the time.

So like many Marines deployed on a warship, I decided to get really jacked.

Space is limited on a ship, so I was lucky to find a place to stash the tuna fish and protein powder.

Getting all that extra food on ship without raising any eyebrows is another story. But to cut to the chase, I ended up weighing around 205 pounds by the end of the deployment, which is pretty

big for someone who's 5 foot 10 inches tall and who was only 160 pounds two years earlier.

What surprised me was how difficult it was to maintain all that muscle. My body did not like

being that big and it let me know in a few ways. If I skipped a day of protein or two days of

exercise, I lost weight, my muscles got smaller, and my strength

decreased. Apparently, my body was trying to maintain homeostasis, a relatively stable body

composition largely determined by genetics, and I had to work extra hard to keep my body

composition outside that window.

What also surprised me was noticing how my brain had a difficult time adapting to the new size,

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