The Spero Performance coaching team in London, Ontario

Our Team

The coaches, partners, and specialists building Spero Performance. Every person here has earned their spot.

Coaches who've been there.

Founder & High Performance Coach

Spero Mantzavrakos

Spero Mantzavrakos is a recognized industry leader in sports performance training with over 35 years of experience helping athletes maximize their potential. As a Certified Strength and Conditioning Specialist and high performance coach, he specializes in speed development, strength, mobility, athletic movement, and endurance. Throughout his career, Spero has trained and consulted with hundreds of elite athletes and organizations across the NHL, NFL, MLB, MLS, UFC, CFL, NCAA, KHL, and OHL. His client base ranges from youth and high school athletes to collegiate competitors, professional athletes, Olympic hopefuls, and All Stars across nearly every major sport. Spero has built a reputation for excellence by developing athletes at every level through individualized coaching, proven training systems, and an unwavering commitment to long-term athletic development. His passion for advancing athletic performance and commitment to coaching excellence continue to influence athletes, coaches, and organizations across a wide range of sports.

Former Head S&C, New York Islanders (NHL)
Former Head S&C, London Knights (OHL)
Former Head S&C, Amur Khabarovsk (KHL)

High Performance Coach

Mason Mantzavrakos

Mason Mantzavrakos is a Certified Strength and Conditioning Specialist dedicated to helping athletes improve strength, speed, power, mobility, and overall athletic performance through evidence-based training. He takes a comprehensive approach to athletic development, emphasizing movement quality, injury prevention, and long-term progress. As a former high-level hockey player, Mason understands the physical and mental demands athletes face and applies that experience to practical, results-driven coaching. Having trained alongside his father Spero, since the age of nine, he combines years of hands-on experience with modern training principles to develop individualized programs for youth, collegiate, professional, and elite athletes. Mason is committed to building confident, resilient athletes by emphasizing consistency, discipline, and proper technique while creating an environment that challenges, motivates, and supports every athlete in reaching their full potential.

Elite hockey background
Athlete-first coaching philosophy

Testing & Athlete Development

Matthew Demaiter

Matthew Demaiter leads athlete testing, biomechanical analysis, and performance evaluations at Spero Performance. He oversees the assessment process, using objective data to identify strengths, address weaknesses, and develop individualized strategies that maximize athletic performance. Matthew holds an Honours Bachelor of Kinesiology from Western University and is a Certified Exercise Physiologist (CSEP-CEP). As a two-time U SPORTS Academic All-Canadian wrestler, he combines a strong academic background with firsthand experience competing at the highest level of university athletics. His expertise in movement analysis, performance testing, and athlete development allows him to provide data-driven insights that help athletes train smarter, move more efficiently, reduce injury risk, and perform at their highest level. Matthew is committed to using science-based assessment and evidence-based training principles to support the long-term success of every athlete.

CSEP-CEP (Certified Exercise Physiologist)
Honours Bachelor of Kinesiology, Western University
Two-time U SPORTS Academic All-Canadian wrestler

The team behind the team.

On-site specialists and advisors who keep athletes healthy, recovered, and performing.

On-Site Physiotherapy

Pro Function Physio

Pro Function operates a clinic inside the facility. Their physiotherapist handles sports injuries, movement screenings, injury prevention, and return-to-play protocols. Athletes can book directly with them.

Sports Injury Rehab
Injury Prevention
Movement Screening
Return-to-Play Protocols

Sport Yoga Instructors

Jeillin & Brad

Jeillin and Brad are a yoga-certified teaching team and married couple dedicated to helping people move better, build strength, and deepen the mind-body connection. Jeillin, an RN of 23 years, has practiced yoga for 20+ years. Brad brings 23 years in emergency services and 15+ years of yoga practice. Trained in Blissology Yoga, focusing on strength, stability, and creating space for joint preservation. Their approach supports injury reduction and promotes sustainable, lifelong integration of movement and wellness.

Strength & Stability
Joint Preservation
Injury Reduction
Mind-Body Integration

Special Supporting Member

Dr. Marie-Eve LeBel

Dr. Marie-Eve LeBel, Associate Professor of Orthopaedic Surgery at Western University and fellowship-trained Sport Medicine specialist, brings extensive expertise in the care of high-performance athletes. Her clinical focus includes advanced arthroscopic treatment of complex shoulder injuries in competitive and elite populations. As a Special Supporting Member of Spero Performance, Dr. LeBel supports the gym's commitment to proper development, injury awareness, and long-term athlete health, reinforcing an environment where young athletes can train safely, build confidence, and pursue their goals with strong professional guidance behind them.

Orthopaedic Surgery
Sport Medicine
Shoulder Injury Specialist
Athlete Health Advisor

Dr. LeBel's affiliation with Spero Performance is limited to educational and advisory support and does not involve clinical services or referral arrangements. She does not provide medical services through the gym, and athletes are free to seek care from any healthcare provider of their choice.

Position coaches.

Skill and technique coaches who've played and coached at the highest levels of Canadian football.

Offensive Line Coach

Sean Jamieson

Western Mustangs

Sean started playing offensive line at the age of 13. As a player he joined the Western Mustangs for the 2012 season and played a five year university career starting at four different positions on the offensive line. Sean was a three time All-Canadian and was selected by the Montreal Alouettes in the 2016 CFL draft. Sean played a seven year career with the Alouettes and won a Grey Cup in 2023. During his time in the CFL Sean completed his MA in Kinesiology with a practicum in coaching. Currently Sean is a full time coach working with the offensive line of the Western Mustangs.

Receiver / DB Coach

Coach PJ Edgeworth

Western University

Edgeworth, a native Londoner, played his university football at York, where he graduated as the school's all-time leader in receptions. He has coached at the high school, summer ball, and CJFL levels, winning championships with South Collegiate and the Forest City Thunderbirds. Edgeworth then joined the Western Mustangs staff for the 2004 season. In his time at Western, Edgeworth has coached on both sides of the ball, specifically defensive backs and receivers, giving him a unique knowledge and perspective on what defensive backs are taught, and how receivers can gain an advantage against them in both man and zone coverage. Edgeworth has helped to develop over 26 OUA all-stars, 16 U-Sport All-Canadians and 10 CFL draft picks. He has been a part of 9 Yates Cup Championships, and the 2017 National Championship teams.

Coming Soon

Lineman Coach

Position coach announcement coming soon.

More ways to work with us.

Customized Athlete Development

Add-on programming layered on top of standard Athlete Development tiers. For athletes who need more specific work outside the group setting.

Get in touch

Private Training

One-on-one coaching with dedicated time and programming. Contact us to discuss availability and rates.

Contact for details

Open Gym Membership

Self-directed access to the floor outside coached sessions. Launching soon for current members and drop-in pass holders.

Coming soon

Want to train with us?

Book a free consultation and we'll help you find the right fit for your sport and goals.

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