about us

We Live To Help Train You

CrossFit is a functional fitness training program that builds strength and conditioning through extremely varied and challenging workouts.  Each day the workout will test a different part of your functional strength or conditioning, not specializing in one particular thing, but rather with the goal of building a body that’s capable of practically anything and everything. CrossFit is extremely different from a commercial gym…and not just because you won’t find any elliptical or weight machines, or Zumba classes.

Constantly varied: Each day there is a prescribed Workout of the Day. The workout might contain Olympic or powerlifting movements, gymnastic movements, and traditional aerobic activities such as running, rowing or jump rope. The best part about it is everything is scalable for every level of fitness. Some workouts are done for time, some for a score, and some for max weight lifted. Life doesn’t come at us as 3 sets of 10, so why would we exercise that way?

What makes us different? We offer 1:1 personal training sessions as part of your onboarding experience Ground Up. We do this as part of your first month’s membership. We care about your onboarding experience and know that CrossFit is for everyone, and one of the ways to ensure YOUR success is to dedicate the time upfront with you. We do this as part of your first month’s Unlimited membership.

We believe in fitness at all levels and ensure you have the resources to be successful at any fitness level. At Ground Up we care about HOW you are moving, not the amount of weight you move. Your lon-term success with functional movement is our #1 priority.

We value our relationships and have a collaborative membership with the Hastings YMCA. Now if you would like to be a member of the YMCA and CrossFit, you can do so at a competitive value! We offer LeanFit as part of our regular class offerings. Not ready for CrossFit just yet? Try LeanFit!

We are the only CrossFit Kids Program in Hastings and offering regular CrossFit Preschool, Kids and Teens classes and the only gym with CROSSFIT CERTIFIED KIDS TRAINERS. We believe in fitness at all ages and have dedicated the resources to invest in your children year around!


Dr. Tiffani Arndt (CF-L2)


Member Since: 2015
Hometown: Lincoln, Nebraska
College: University of Nebraska at Omaha
Profession: Owner of Ground Up Fitness and Nutrition, CrossFit Ground Up and Ground Up Nutrition.
Qualifications: CrossFit Level 2, CrossFit Kids Certified Trainer, Coaching the Aging Athlete Certified,  LifeBase Solutions Nutrition Coach, Precision Nutrition PN 1, Doctor of Nursing Practice.

I love helping others achieve their fitness and nutrition goals. Since Nutrition is the building block of fitness, I enjoy helping others live their best life and learn how to eat to not only decrease body fat and gain muscle, but to eat for everyday living.  As a CrossFitter who is almost 50, I am committed to the older athlete, teaching adults in the middle of their life how to move safely to ensure longevity. In my free time, I enjoy walking my dogs, spending time with family and friends, gardening, and being outside living life.

James (JJ) Arndt (CF-L2)


Member Since: 2013
Hometown: Hastings, Nebraska

Profession: Owner of Ground Up Fitness and Nutrition, CrossFit Ground Up and Ground Up Nutrition, Master Electrician
Qualifications: CrossFit Level 2, USAW Certifications

I started CrossFit in 2013, and fell in love with the sense of accomplishment that exercise gives me. Now owning Ground Up Fitness and Nutrition allows me to share that passion with others. I am proud that everyone who walks into this gym feels welcome and leaves each class knowing they just improved their health and longevity. I also own an electrical contracting business, so when I am not working or working out, I love to spend time with my family and friends. We have 3 grandkids that are the best!

Abigail Lauters (CF-L2)


Member Since: 2013
Hometown: Lawrence, Nebraska
College: Peru State College
Profession: Coach at Ground Up Fitness and Nutrition and CrossFit Ground UP.

Qualifications: CrossFit Level 2, Coach at Ground Up since 2015, Numerous continuing education regarding the Post Partum Client.

I am proud of the fact that since coaching at and being a member of Ground Up, I have helped all kinds of people at different skill levels to improve their fitness. A huge personal accomplishment is that I continued to do CrossFit throughout my pregnancies, and learned and practiced how to come back stronger after each one. I am confident and capable to modify workouts for pregnancy and postpartum moms. 

My goal as a coach is to help members reach their best fitness levels so they can thrive in all areas of life now and in the future. 

I live in Hastings with my family and like to read and watch sports in my free time. 

Chelsey Wiseman (CF-L3)


Member since: 2014

Coach since: 2021

Qualifications: Certified CrossFit Level 3 Trainer, Spot the Flaw Certificate, Lesson Planning Certificate, Scaling Certificate, CPR Certified

Hometown: Hastings, NE


Some of my proudest accomplishments are helping people of all walks of life improve their health and fitness through CrossFit. Also getting my Level 3 Certification and being one of six Certified Level 3 Trainers in the state of Nebraska. My goal as a coach is to help anyone that walks through the door and improve their life! I like to cook and bake and hang out with my friends and family in my free time!

Angelo Martinez (CF-L3)


Member Since: 2017

Hometown: Colorado Springs, Colorado

College: Hastings College

Profession: Business Teacher at Hastings High School

Qualifications: CrossFit Level 3 Coach, Precision Nutrition Certified, Masters of Arts in Teaching,  and multiple Crossfit Endorsements

Some of my greatest accomplishments are playing Football at Hastings College for 3 years. After Football I played Rugby for 5 years with Tri-City Raptors. I have completed 75 Hard, Married the love of my life and have 2 amazing kids. I love new challenges and finding the next thing I check off my list. Whether it’s mountain climbing, biking, running or disc golf; I love being active and being outdoors.



701 East 39th Street
Hastings , Nebraska 68901


Have a question? Want to get started?