Inclusion Criteria:  Healthy will be defined as screened by the PAR-Q+ (The Physical Activity Readiness Questionnaire for everyone) Regularly active, as defined by being in the top 20% of age specific scores on the iPAQ (the International Physical Activity Questionnaire) Between the ages of 8 to 16 years An age and sex-specific minimum of 75th percentile Beep Test level  Exclusion Criteria:  Inability to meet health and physical activity guidelines according to the PAR-Q+ and iPAQ Inability to adhere to any of the protocol guidelines Biological age outside of -0.5 to +1.5 years from PHV for adolescents, and > -1 years from PHV for children