STRENGTH TRAINING VS. AEROBIC INTERVAL TRAINING TO MODIFY RISH FACTORS OF METABOLIC SYNDROME Casey Graham Michele Benanti Tiffany Meier
First, a definition . . . • METABOLIC SYNDROME – According to MayoClinic, metabolic syndrome is a group of symptoms that are also associated with general obesity: elevated blood pressure, excess fat, dyslipidemia (abnormal amount of fat in blood), and impaired endothelial function. What differs ‘MS’ from general obesity is that sufferers are ‘apple-shaped’; they carry most of their excess fat around their abdomen.
VARIABLES • Independent Variable – The training regimes: Strength training (ST), aerobic interval training (AIT), combination of both ST and AIT (COM) • Dependent variable – Results of many post tests following the 12 week training session.
RELATIONSHIPS • Study is looking for the relationship between different training regimes, specifically ST, and their adverse affects against MS.
HYPOTHESIS, or lack thereof . . . • While never explicitly stated, at the start of the article the author writes that “physicians do not often recommend ST for patients with cardiovascular disease”, but “the aim of the study was to evaluate the effects of AIT vs. ST vs. COM on factors of MS to find the most effective exercise regime”.
METHODS:Sample • 43 participants (26 men, 17 women) • Volunteer sample • Exclusion criteria • Randomized into either AIT, ST, COM, or control group • It should be noted that the study had three members drop out. One from the ST, the control, and one from the COM. The person from the COM withdrew due to rheumatic pain. • All members instructed to continue medications. These included beta-blockers (which stimulate the heart)
METHODS:Exercise Regimes • ST – 3 x week/ 12 weeks – 11 members • W/U of 15-20 reps at 40-50% (based on 1 rep. max) • 1st week, workouts at 60% of 1 rep. max • Weeks 2-12, three sets at 80% of their 1 rep. max • Two different programs: 1) low row, bench press, hack lift 2) lat. Raise, triceps pulldown, biceps curl, low row, and planks • Total workout time: 40-50 minutes
METHODS:Exercise Regimes • AIT – 3 x week/12 weeks – 11 members • Walking or Running • 10 minute W/U at 70% of peak heart rate • 4 intervals at 90-95% of HRpeak, with a 3 minute recovery period at 70% HRpeak between each interval • 5 minute cool down • Total time: 43 minutes
METHODS:Exercise Regimes • COM – 3 x week/12 weeks – 10 members • AIT twice a week, ST (program 1) once a week • CONTROL (11 members) – These participants were asked not change their dietary patterns or physical activity level.
METHODS:Testing • Several pre and post tests were performed to access the results of the study. • Risk factors defining metabolic syndrome: waist circumference, HDL levels, Glucose levels, triglyceride levels, SBP, and DBP. • Physiological parameters measured before/after 12 wk training period: Weight, BMI, Fat mass, Lean body mass, Bone mineral content, Resting metabolic rate, Cholesterol levels • Aerobic capacity and maximal strength: Peak O2 uptake and one rep. max
EXTERNAL VALIDITY • Study appears to generalize to people with metabolic syndrome • Small, uneven sample • Positive relationship • Overall, good external validity because exercise almost always promotes a healthier person • Things that could’ve strengthened it: larger sample size, more even participation (men v. women)
CONSTRUCT VALIDITY • Face validity strong because they measured what they meant to measure. • Content validity was strong as well because it measured items relevant to the items of the study • Mono-Operation bias is irrelevant because testers had multiple IVs • Mono-Method bias is, too, irrelevant because multiple tests were conducted to ensure a solid conclusion (albeit, a wishy-washy conclusion)
CONSTRUCT VALIDITY • THREATS: • Interaction of different treatments – Sample of people in the study is too small to be an adequate representation; this is acknowledged in the article. • Interaction of Testing and Treatment – People participated in this study to lose weight and be healthy. It is already known that if someone is overweight and begins to exercise, they will lose weight and become healthier. For example, a friend of mine (Casey’s), had been overweight most of her life and started to work out this summer. After only a few weeks of training, the weight began to slide off. True story.
INTERNAL VALIDITY • Temporal precedence - MS comes before the training regimes • Covariation – Exercise results in reduction of MS symptoms; if exercise then healthy . . . More exercise, more healthy, etc. • No single group or multiple group threats • Possible social threats: resentful demoralization1, experimenter bias2, diffusion/imitation of treatment3
INTERNAL VALIDITY • THREATS • 1. One group may become jealous of the others training regime (of lack of training) and therefore adversely effect the results. • 2. Since this was not a blind or double-blind study, the experimenter may have, for some reason, favored one group over the other • 3. Some members from one group may have started doing extra workouts on their own. (EX. A member of the ST team starts walking after dinner on their own)
INTERNAL VALIDITY • R O X1 O • R O X2 O • R O X3 O • R O X4 O
RESULTS • Overall, the study concluded that ST, AIT, and COM have beneficial effects on physiological abnormalities associated with MS. • Strong decrease in DBP and SBP after AIT • Researchers concluded that, after the 12 wk. program AIT was, overall, more effective than ST and COM in reducing physiological effects of MS