LisaS
06-05-2006, 01:02 AM
Exercise & Insulin Sensitivity
Effect of the volume and intensity of exercise training on insulin sensitivity
J Appl Physiol, Jan 2004; 96: 101 - 106.
This study from 2003 was trying to find the exercise prescription that would maximize increases in insulin sensitivity. The researchers divided their treatement group to different combinations of volume and intensity of walking/jogging programs for 6 months. The groups were low volume/moderat intensity, low vol/high intensity, high vol/high intensity (details are in the study). The subjects were "middle aged, overweight/obese, previously sedentary" and "they exhibited evidence of dyslipidemia".
The authors summarize the findings in the 1st paragraph of the discussion section:
The main finding of the present study was that exercise programs consisting of a training duration of ~170 min/wk, regardless of variations in exercise intensity (range, 40–80% O2 peak) and weekly training volume (12–20 miles/wk) (Table 2), improved insulin sensitivity to a similar degree (Fig. 1). Our findings (Table 3, Fig. 1) thus suggest that, within the exercise training paradigms used in the present study, exercise duration is one of the primary factors that controls the response of insulin action to exercise training. The conclusion that weekly exercise duration appeared to be an important variable influencing changes in insulin sensitivity was reached by integrating several pieces of information. First, weekly exercise frequency (~3 sessions/wk) and volume (~12 miles/wk) were similar between the low-volume/moderate-intensity and lowvolume/high-intensity groups (Table 2). However, SI was enhanced to a greater extent (Fig. 1) with the exercise training encompassing the longer weekly training duration. Second, both of the exercise training groups with longest weekly training durations (low-volume/moderate-intensity and high-volume/high-intensity groups, ~170 min/wk) enhanced insulin sensitivity to a similar degree (Fig. 1), independent of exercise intensity and weekly training volume (Table 2). Third, the increment in insulin action in the longer duration vs. the shorter duration groups remained evident after statistically adjusting for differences in the change in body mass (Table 3) and exercise adherence and frequency (Table 2) between the groups (see RESULTS). These findings suggest that exercise duration should be considered when designing training programs with the intent of improving insulin action and reducing the risk for CVD.
they continue:
In summary, physical activity encompassing a wide range of intensity and volume prevents increases in the insulin resistance that develops progressively with a sedentary lifestyle. However, an exercise prescription that incorporated an exercise duration of ~170 min of exercise/wk with a frequency of three to four sessions per week improved insulin sensitivity significantly more than a program utilizing ~115 min of exercise/wk and a frequency of three sessions per week, regardless of exercise intensity and volume. Exercise duration should thus be considered when designing training programs with the intent of improving insulin sensitivity.
the study can be read here:
http://jap.physiology.org/cgi/search?sortspec=relevance&author1=&fulltext=&pubdate_year=2004&volume=96&firstpage=101
Effect of the volume and intensity of exercise training on insulin sensitivity
J Appl Physiol, Jan 2004; 96: 101 - 106.
This study from 2003 was trying to find the exercise prescription that would maximize increases in insulin sensitivity. The researchers divided their treatement group to different combinations of volume and intensity of walking/jogging programs for 6 months. The groups were low volume/moderat intensity, low vol/high intensity, high vol/high intensity (details are in the study). The subjects were "middle aged, overweight/obese, previously sedentary" and "they exhibited evidence of dyslipidemia".
The authors summarize the findings in the 1st paragraph of the discussion section:
The main finding of the present study was that exercise programs consisting of a training duration of ~170 min/wk, regardless of variations in exercise intensity (range, 40–80% O2 peak) and weekly training volume (12–20 miles/wk) (Table 2), improved insulin sensitivity to a similar degree (Fig. 1). Our findings (Table 3, Fig. 1) thus suggest that, within the exercise training paradigms used in the present study, exercise duration is one of the primary factors that controls the response of insulin action to exercise training. The conclusion that weekly exercise duration appeared to be an important variable influencing changes in insulin sensitivity was reached by integrating several pieces of information. First, weekly exercise frequency (~3 sessions/wk) and volume (~12 miles/wk) were similar between the low-volume/moderate-intensity and lowvolume/high-intensity groups (Table 2). However, SI was enhanced to a greater extent (Fig. 1) with the exercise training encompassing the longer weekly training duration. Second, both of the exercise training groups with longest weekly training durations (low-volume/moderate-intensity and high-volume/high-intensity groups, ~170 min/wk) enhanced insulin sensitivity to a similar degree (Fig. 1), independent of exercise intensity and weekly training volume (Table 2). Third, the increment in insulin action in the longer duration vs. the shorter duration groups remained evident after statistically adjusting for differences in the change in body mass (Table 3) and exercise adherence and frequency (Table 2) between the groups (see RESULTS). These findings suggest that exercise duration should be considered when designing training programs with the intent of improving insulin action and reducing the risk for CVD.
they continue:
In summary, physical activity encompassing a wide range of intensity and volume prevents increases in the insulin resistance that develops progressively with a sedentary lifestyle. However, an exercise prescription that incorporated an exercise duration of ~170 min of exercise/wk with a frequency of three to four sessions per week improved insulin sensitivity significantly more than a program utilizing ~115 min of exercise/wk and a frequency of three sessions per week, regardless of exercise intensity and volume. Exercise duration should thus be considered when designing training programs with the intent of improving insulin sensitivity.
the study can be read here:
http://jap.physiology.org/cgi/search?sortspec=relevance&author1=&fulltext=&pubdate_year=2004&volume=96&firstpage=101