To defeat the Jew IRL, you must defeat the Jew within yourself.

How to better yourself:

Go to the gym at least three times a week, and fill the other days with physical activity as well.
Take up one of the following physical hobbies to do on off days:
>Competitive Intramural Sport (soccer, football, basketball, lacrosse, etc.)
>Competitive court sports (tennis, badminton, racquetball, jai-alai)
>Natural activities (hiking, trail-building, rock-climbing, kayaking)
>Endurance/Conditioning (swimming, running, marathons, sprints, 5Ks)
>Combative sport (martial arts, wrestling, grappling, Jiu-Jitzu)
>Game sports (golf, skeet shooting, disc golf, archery)

If you do not participate in at LEAST one of these activities, you should start. Many of these are easy to pick up and have a thriving social community about them. Stay active, develop hobbies, and make friends at the same time.
This is the very good /fit/ Sticky. Skip to the exercise section for some good starting routines if you’re new.
http://liamrosen.com/fitness.html

Stop consuming unnatural foods. Fast food, shit packaged food like potato chips, Doritos, candy. Instead, your snack food should be things like beef jerky, pistachios, almonds, raw spinach, carrots, cheese.
Eat fruit. Eat steak, eggs, nuts.
Eat veggies. Eat veggies that you grew yourself, if you can.
Eat fish. Eat fish that you caught yourself, if you can.

Stop drinking $8 craft hipster beer. There’s a reason they’re big right now, and it’s because the ATF doesn’t make them put nutrition facts on the cans. All those IPAs and Doubles and Stouts and craft shit usually hover around 30g carbs and 300+ calories each. Although the social benefits of drinking occasionally with friends does drastically outweigh the negative effects, you should still keep your drinks to one or two, whiskey or gin only.
Do not drink soda, ever. The only acceptable drinks are water, coffee, wine, and whiskey/gin (occasionally).