Rock Steady Boxing
EastBay in Concord CA
Fighting Back against Parkinson's disease with Functional Fitness!! Measurable and repeatable specialized Parkinson's training for you or your loved ones.
During COVID-19 We are offering (3) Classes A Week (Very Small Socially distanced Groups) in our 7500sq ft Facility in Concord, CA .
"In Gym" training days are,
Tuesday, Thursday, Friday: 10:30am-11:30am
We also offer "at home" Online Training with new weekly videos as well as a vast video Library of training work outs from Rock Steady Boxing Online University.
RSB EastBay, Concord is
Located inside of CrossFit OverWatch at
Address: 2372 Stanwell Cir. Concord, Ca 94520

Call us today at
(925) 785-1272
Coach Tony DeSousa
Coach Jimmy Greninger
Coach Ashley Greene
Coach Dean Moskovitz

Coach Jimmy Greninger
*National Academy of Sports Medicine
(NASM CPT)
*USAW LV1 Coach (Under Coach Pendlay)
*API Caveman Certified Instructor
*UFC LV5 Certified Head Ultimate Trainer
*BioDensity Certified
*DotFit Nutrition Certified
*CPR/AED Certified
*CQC Scientific Fighting Congress Member
*B.A. in Psychology from CSUN
(California State University Northridge)
*2008 CrossFit LV1 Coach
*2009 CrossFit Football Coach
*2009 CrossFit Nutrition Coach (Under R.Wolf)
*2010 CrossFit Running/Endurance Coach
*2013 CrossFit Mobility (Under K. Starr)
*2014,15,16,17,18,19,20,21 CrossFit Judges Course
*NV State Athletic Commission Credential
*CA State Athletic Commission Credential
Jimmy was drafted out of High School by the California Angels in the 7th Round. A highly recruited DIV1 scholarship Athlete, he played both Football and Baseball, was a Team Captain and earned a Degree in Psychology from CSUN. Jimmy was picked up by the Packers and Chargers as a Wide Receiver/Kick Returner before a reoccurring injury kept him sidelined for good. In 2006 Jimmy found CrossFit through his childhood friend, Jeremy Jones, founder of Diablo CrossFit and was instantly engulfed into the CF lifestyle. Jimmy embraced his love for Coaching and started Teaching CrossFit in 2006 and received his CF LV1 in 2008. Coach Jimmy became a Professional UFC MMA Trainer/Corner man and has worked with some of the biggest Super Stars and Champions of the UFC and StrikeForce. Coach Jimmy has also prepared and trained several active Marines, NAVY SEALs, ARMY Rangers, Green Berets, Para-Jumpers and NFL players. Coach Jimmy Designed and Implemented the “DUT” Training Program that is run in all UFC Gym locations World Wide and has helped to build some of the Largest CrossFit, Fitness and Nutrition programs in California. Coach Jimmy is Founder of the multi-sponsored “UFC Competition Team” that races in EPIC Series, Tough Mudder, Spartan Race, Warrior Dash, GORUK Challenges and Urban Athlon events. Jimmy was Co-Founder of the MMAJacked Training Center w UFC Legend Chuck Liddell, Jimmy is Founder of the Sterling Aviation Pilot Fitness Club, Co-Founder of The Modern Caveman Challenge and Co-Fitness Editor of the published “Caveman Diet Handbook.”
Jimmy has had the privilege and Honor of Training several Officers from the following Agencies:
USAF
USMC
US ARMY
US NAVY
US Coast Guard
NAVY SEALS
US Special Forces
Central County SWAT
Marin County SWAT
Oakland SWAT
West County SERT
Sacramento PD
Pittsburg PD
Berkeley PD
San Ramon PD
Oakland PD
Martinez PD
Walnut Creek PD
Concord PD
San Francisco PD
Hayward PD
Santa Barbara PD
BART PD
Alameda County SD
Contra Costa County SD
Monterey County SD
Marin County SD
Antioch PD
ConFire
Mountain View Fire Dept
San Ramon Fire Dept
San Francisco Fire Dept