The Insulin Sensitivity Using Aerobic Interval Conditioning
Condition: Pre-diabetes
MeSH terms: Insulin Resistance; Prediabetic State
Study type: Interventional

Summary: 
      The Insulin Sensitivity using Aerobic Interval Conditioning (ISAIC) trial will compare
      traditional aerobic training (AER) to interval training (INT) in sedentary, overweight/obese
      men at risk for pre-diabetes. The investigators will randomly assign 42 individuals to 3
      months of monitored exercise using a randomly assisgned design where participants will
      exercise under either AER or INT training conditions. The AER training condition will be
      consistent with "standard-of-care" recommendations. Exercise training will entail one 3-month
      blocks of either AER or INT. Training will consist of 1) a 1-month ramp up period, 2) 1-month
      of traditional aerobic training and 3) 1-month of either continued AER or INT.
    

Detailed description: 
      It is currently estimated that type II diabetes (T2D) affects 5-8% of adults. Also recognized
      is a transitional group of individuals whose control of blood glucose is abnormal, but not
      yet considered diabetic. These individuals are classified as having pre-diabetes, which is
      defined as having impaired fasting glucose (IFG;fasting glucose 100-125 mg/dl), impaired
      glucose tolerance (IGT; post 2-h glucose load; 140-199 mg/dl) or both. This population
      represents a significant segment of the population as it is estimated that approximately 23%
      of Americans have pre-diabetes (IGT or IFG). Two unifying features associated with these
      metabolic impairments is a strong link to obesity and physical inactivity. Regular exercise
      positively influences IFG/IGT and obesity, and represents an important therapy for preventing
      the progression to T2D by enhancing several mechanisms of action including improved: glucose
      metabolism, muscle respiratory capacity, mitochondrial respiratory chain activity and
      ß-oxidation. Importantly, the dose of physical activity required to promote metabolic
      benefits appears to be obtainable for most individuals with as little as ~1000 kcal/w of
      aerobic activity.

      While most exercise policy statement guidelines recommend that exercise be performed within
      an intensity ranging of 40-85% V02max, newer guidelines, such as the recently updated
      Physical Activity and Public Health Recommendations recognize that few studies have examined
      the effects of intensity, duration, or frequency of physical activity independent of their
      contribution to the total amount of physical activity. Accordingly, this writing group
      specifically recommended that, "based on recent data, there is some indication that
      vigorous-intensity activities may have greater benefit for reducing cardiovascular disease
      and premature mortality than moderate-intensity physical activity .... that much more work is
      needed is this area."
    

Intervention name(s): Behavioral: exercise
Intervention type(s): Other
Intervention description(s): Specific Aim: We will identify, recruit, assess, and randomly assign 42 sedentary, overweight-obese individuals who are at risk for pre-diabetes to an AER or INT training group in order to test the hypothesis:
• Individuals randomized to INT will have greater improvements in insulin sensitivity than individuals assigned to traditional AER.
Secondary Aim: We will measure maximal cardiorespiratory fitness (VO2max/peak) in order to test the hypothesis:
• Individuals randomized to the INT group will have a greater improvement in VO2max/peak than individuals in traditional AER group.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: diabetes; exercise; insulin resistance; interval training; physical activity