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Register Now for MavUp Development Clinics

Mountainside JBO is excited to partner with GRINDTIME FIT to provide advanced winter training and development opportunities for our players this year.   These will take place starting Nov 14 at Grindtime and will run Tuesday, Thursdays and Saturday for 10 weeks.  


Workouts will be indoors at Grindtime and will last 1 hour per session.  

Please know that winter training is optional but is also highly recommended for players for attend, so that they can continue to build and/or sharpen their skills during the off-season, leading up to the Spring season. 

If you have any questions about winter workouts or need additional information, please contact us at

This registration session will allow you to complete contact information, sign up for participation, and remit payment. Please read through each page carefully to ensure that all information is provided accurately. To complete registration through our secure site, please have your Visa or MasterCard handy to make payment.  

We thank you for your interest in Mountainside JBO and we look forward to working with your youth player as they continue their baseball growth and development!

At the conclusion of or GRINDTIME program, we will begin offering skill specific clinics and baseball specific sessions.  So, check back periodically and look out for notices on our social media and leaguewide emails.  


Champions are made in the off-season

A solid and productive off-season baseball training program can make or break your in-season success for the coming year. Once the baseball season is over and you've had time to rest your body, it's time to begin preparing for the next season.   This will come in the way of playing Fall sports such as football, soccer, lacrosse, and a host of other sports.  It also can entail playing a less demanding Fall  Baseball season, as well as strength & conditioning programs.  

The foundation for enhanced success on the baseball diamond in the Spring/Summer is built with a good off-season training program. It's important for baseball players to use the off-season to develop their core strength, increase speed & agility, increase overall body strength with plyometrics and strength building exercises, and  then honing their baseball skills with reps meant to build solid fundamentals.  

While we are big proponents of sport rotation and resting, an off season program need not interfere with other sports you're participating in and/or tax your baseball specific body parts.   A good off-season program will work specifically on skills that don't require continued repetitive stress, such as throwing.  

If you wait until the start of the baseball season to work hard and get better, you're already too late.   

MavUp Your Winter Baseball Workouts!

For youth baseball players the cold rainy winter is the ideal time to focus their efforts on improving their baseball potential by developing muscular strength and explosive power.   These enhanced physical attributes transfer to the baseball field as quickness, speed, bat speed, throwing velocity and overall power.  And provide the tools needed to take one's game to the next level.   At some point, after mechanics get dialed in and improved, only getting bigger and stronger will manifest into bigger hits and more powerful pitching and throws.   As well as the ability to play at  high level for a long baseball season.   Developing resiliency and stamina make a big difference over the long haul.   

Under most circumstances, we encourage youth athletes at JBO age to participate in multiple sports and not specialize too early.   However, that doesn't mean setting a sport aside totally.   Players need to continue to work on S&C and refine their baseball skills.   Even if part time while playing other sports and participating in other activities.   Bottom line, baseball performance in Spring/Summer will never be optimized without a consistent and well structured off-season training, conditioning and developmental program. 

Home Winter Baseball Workout Basics

While there are many good private workout options for youth players in the Beaverton area, a productive home based workout regimen aimed at improvement baseball functional strength and skills is an absolute necessity and should include the following training:

Core Training

Core strengthening exercises are vital to increasing your baseball power, both for throwing and hitting. Start your winter baseball workouts with core training that works the abdominal muscles, the torso, hips and thighs.   There are a host of great exercises that will target these muscles, such as sit-ups, crunches, planks and med ball throws, which build powerful rotational power and speed. Move on to legs with a combination of wall squats and lunges, then work through upper-body push/pull exercises.  A complete development plan will be located in The Dugout-Players tab...


Rotator Cuff Strengthening & Flexibility Work

Arms are our greatest assets in baseball, so it is crucial to take care of and nourish them.   Thusly, doing drills and workouts specifically targeted to strengthen these small, albeit vitally important muscles should be at the foundation of any baseball specific S&C program.