The Relationship Between Exercise Frequency, Intensity, and Restoration of Cardiometabolic Health
Condition: Overweight or Obesity
MeSH terms: Overweight
Study type: Interventional

Summary: 
      Regular physical activity is well established to decrease the risk of cardiometabolic
      diseases. While research has characterized responses based on exercise intensity, many
      beneficial effects of exercise are transient in nature, and therefore exercise frequency may
      play an important, yet currently under-appreciated, role in improving health. The purpose of
      this study is to determine the efficacy of 6-week high-frequency endurance (END) or
      low-frequency sprint (SIT) training with respect to reducing clinically relevant
      cardiometabolic risk factors in overweight/obese males. It is hypothesized that END,
      performed at a greater frequency than SIT, will markedly improve cardiometabolic health,
      while low-frequency SIT will not.
    

Detailed description: 
      Involvement in regular physical activity is known to elicit systemic adaptations and reduce
      the risk of cardiometabolic diseases, including hypertension, obesity, dyslipidemia, and
      hyperglycemia. Traditional physical activity recommendations suggest that 150 minutes of
      moderate-intensity continuous endurance (END) exercise dispersed over 5 days per week is
      sufficient to improve physical fitness in adults. However, given the commonly cited barrier
      of "lack of time," literature has recently focused on time effective sprint interval training
      (SIT), obtaining equivalent increases in aerobic capacity and acute glycemic regulation
      compared to classical END exercise when protocols are work-matched. Despite these
      similarities, END is conducive to daily sessions not feasible of SIT. As improvements in many
      clinically relevant risk factors are transient in nature following exercise, it remains
      imperative to assess the implications of variable frequency exercise regimes performed as per
      general practice (i.e. high-frequency END, low-frequency SIT). Furthermore, improvements in
      cardiovascular outcomes following END have been shown, in some instances, to be absent in
      response to SIT, suggesting END may be more beneficial for cardiovascular health. Therefore,
      the current study aims to assess several markers of cardiovascular (aerobic capacity, blood
      pressure, arterial stiffness, vascular endothelial function) and metabolic (glucose
      tolerance, lipid tolerance, body composition) health following 6-weeks of high-frequency END
      or low-frequency SIT, performed as per general practice. Combined, this research will provide
      important insight into the under-appreciated role of exercise frequency for improving
      cardiometabolic health.
    

Intervention name(s): Endurance Exercise Training (END); Sprint Exercise Training (SIT)
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Physical activity will be conducted on cycle ergometers under supervision. Participants will exercise 5 days a week for 30 minutes (Week 1-2); 35 minutes (Weeks 3-4); or 40 minutes (Weeks 5-6) at 60% VO2 peak.; Physical activity will be conducted on cycle ergometers under supervision. Participants will exercise 3 days a week involving a 3-minute warm-up, followed up 4 repetitions (Week 1-2); 5 repetitions (Weeks 3-4); or 6 (Weeks 5-6) repetitions of 30 seconds at a maximal intensity with 2 minutes' rest in between. Exercise will conclude with a 2-minute cool-down.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This study is a 6-week exercise training study, with two possible parallel training groups: endurance (END) or sprint (SIT) training.
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Endurance training; Sprint interval training; Glycemic regulation; Lipid homeostasis; Cardiovascular health