*Confirmed working after 1.06*.
For this guide we will be maxing 'Athletics' under the 'Body' attribute. Make a manual save before you begin if you wish.
1. Max out 'Body' Attribute to level 20.
2. Buy any 'Berserk' Operating System Cyberware from a Ripper Doc and equip. (I used Militech Berserk MK.5. Available at the Westbrook, Charter Hill District ripperdoc)
3. Activate Berserk mode, LB+RB together while on foot outside
4. Start sprinting.
5. While sprinting, press B to perform a slide
6. While sliding/mid slide, press 'Menu' button.
7. That's it. Sit back and let it rack up. The progression will go up automatically.
8. Stay in the menu so progress isn't interrupted by coming out of the slide.
9. Achievement popped as soon as I hit Level 20 Atheletics, while inside the Attributes/Body screen.
Note: To check progress. Go into Body attribute. Then back out to the Attributes screen. Wait a few moments, and them go back into the Body screen. The progress will have increased. I went from Level 9 to 20 in about 15-20 minutes.