Our Team

Jenny Jeffrey

Coach, Dietitian, Co-Owner

  • Certifications
  • Registered Dietitian
  • NSCA Certified Strength & Conditioning Specialist
  • IOC Diploma in Sports Nutrition
  • CrossFit Level 2 Trainer
  • CrossFit Weightlifting Trainer
  • Certified Diabetes Educator
  • CanFitPro Personal Trainer Specialist
  • CPR + AED Certified




Jenny has a strong passion for fitness, nutrition and health and is excited to share her enthusiasm with her community. As a Registered Dietitian, Jenny has gained a wealth of knowledge and expertise in counselling a wide range of individuals. Her specialties are weight management, sports nutrition, diabetes management, and general healthy eating to support a balanced lifestyle. Her training with the International Olympics Committee and the National Strength and Conditioning Association has given her the knowledge to work with elite level athletes, and take their performance to the next level. CrossFit was the icing on the cake, and the missing link to bring all of her expertise together.

Nathan Jeffrey

Coach, Co-Owner

  • Certifications
  • CrossFit Level 1 Trainer
  • CrossFit Kids Trainer
  • CrossFit Gymnastics Trainer
  • CPR + AED Certified




Nathan has played team sports from a very young age, the dominant ones being Rugby and Football. After realizing how hard these sports were on his body without effective training, Nathan converted to the healthier and safer sport of CrossFit, and has never looked back.

With a positive and playful personality, he was drawn to teaching CrossFit Kids. The idea of making exercise a desirable habit instead of a chore for our future ground breakers seemed like a no-brainer.

Sherry Dean





With more than 30 years in the fitness industry, CF-L1 trainer is Sherry’s newest venture. Her fitness background includes personal training, bodybuilding, firefighter combat challenge competitor and she writes a fitness column for Fire Fighting in Canada. She studied kinesiology at Acadia and is also currently in the process of completing her Ace Peer Fitness Instructor certification. Sherry is excited to bring her enthusiasm and passion to an already awesome Crossfit OnSide team.

Tristan Kay


  • Certifications
  • CrossFit Level 1 Trainer
  • NCCP Weightlifting Trainer




Tristan has been doing Crossfit for the last 5 years. He was introduced to it by his best friend one weekend when he suffered through a partial Fight Gone Bad and has been hooked ever since. Just over 2 years ago he discovered his love for Olympic Weightlifting. In the time since then he has competed twice at the provincial level and is in the process of finishing his NCCP Level 1 Weightlifting certification. Tristan has also just completed his Crossfit Level 1 and can’t wait to help the community at Crossfit Onside improve their Oly skills.

Eileen Du Plooy


  • Certifications
  • CrossFit Level 1 Trainer
  • Remote and wilderness first aid and CPR (Red Cross)
  • Sea Kayak Guide (Paddle Canada level II)
  • Yoga Fit Level 1
  • Functional Movement Screen Certified
  • Agutsu Kettlebell Certified
  • High Five Principles of Healthy Child Development – Quest 1 Course
  • Athletic First Responder (Red Cross)
  • Saint John Ambulance Standard First Aid, CPR level C and AED
  • National Lifeguard Service Certification (NLS)
  • Certified Personal Trainer (Canadian Society for Exercise Physiology)
  • Certified Personal Trainer (Federation of International Sports, Aerobics & Fitness Inc.)
  • Can Fit Pro Instructor (Goodlife Personal Training Institute)
  • Olympic lifting Instructor (National Coaching Certificate Program club coach)
  • Rock climbing Instructor (Climbing Wall Association)
  • TRX R4 Trainer (Suspension Training)
  • Indoor Cycling Instructor
  • Athletics Instructor - Track and Field
  • Field Hockey Coach (Sport Specific Conditioning for team sport)
  • Personnel Support Services Fitness Instructors & Tactical Athlete Training Certified (Canadian Forces)
  • BFTA Basic Fitness Trainer assistant Instructor (Canadian Forces)
  • Athletic Trainer (Canadian Forces) Level II Taping
  • Currently working on Gymnastic body’s Foundation course and Twist Conditioning Bronze Curriculum




Eileen has been involved in sport her entire life; gymnastics, field hockey, rugby, cricket, riflery and Powerlifting at national and international levels. She qualified for the International Powerlifting Federation World Championships in 2014 and 2015, ranking 71st in the World and currently ranked 21st in Canada.  With a passion for sport, she decided to go to University and study Kinesiology (SET).  Within the first few months of study, she realized this was what she wanted to do for a living. Eileen has spent the last 5 years as a Fitness and Sports Instructor with the Canadian Forces, working closely with our military members and their families.  She have also been fortunate to be selected to deploy with the Navy overseas.

In her search to become a more well-rounded athlete and to shake up her training, Eileen discovered CrossFit. It was exactly what she was in search of and found an amazing, supportive, driven and competitive community that shares her enthusiasm.  Eileen takes great pleasure from coaching individuals, helping them set goals for an active lifestyle, and realize the life changing possibilities of this journey.  It has become her passion, to guide clients through this amazing journey, as they discover more about themselves and gain the proper knowledge to continue on the path of an active and healthy lifestyle.  Eileen has traveled from Africa to Ireland, then Spain and now Canada, sharing her passion and continuing to gain knowledge and expertise on different trends in this field.  Eileen is excited to share her passion with other like minded individuals!