O N L I N E L E T T E R S
(240.1 6 55.1 mg/dL), cycling (242.4 6 likely most effective, and elapsed time
OBSERVATIONS 48.8 mg/dL), conditioning machines since eating should be considered.
(235.9 6 48.8 mg/dL), and dancing
(237.4 6 45.3 mg/dL, P , 0.05). Moder-
Blood Glucose ate exercise resulted in a mean decrease of SHERI R. COLBERG, PHD1
232.7 6 44.1 mg/dL, whereas blood glu- MANUEL J. HERNANDEZ, MENG2
Responses to Type, FATIMA SHAHZAD, BS2
cose only decreased 228.0 6 53.6 mg/dL
Intensity, Duration, after vigorous activity of all durations (P , From the 1Old Dominion University, Norfolk, Virginia;
and Timing 0.05). Longer exercise duration generally and the 2 Diabetes Hands Foundation, Berkeley,
of Exercise resulted in increasingly greater decreases California.
Corresponding author: Sheri R. Colberg, scolberg@
in blood glucose for exercise intensities
odu.edu.
combined (P , 0.05) and moderate exer- DOI: 10.2337/dc13-0965
cise (P , 0.001) but not necessarily for
T
2013 by the American Diabetes Association.
he Big Blue Test (BBT) is an annual vigorous exercise alone (Table 1). Exer- Readers may use this article as long as the work is
initiative by the Diabetes Hands cise undertaken 1 and 2 h after eating led properly cited, the use is educational and not for
Foundation to raise awareness of to a similar decrease (240.1 6 47.2 and prot, and the work is not altered. See http://
the importance of physical activity in creativecommons.org/licenses/by-nc-nd/3.0/ for
240.1 6 45.9 mg/dL, respectively), but details.
managing diabetes. Individuals with di- both were more than exercise done for
abetes voluntarily exercise and record either 30 min (228.6 6 50.6 mg/dL) or
self-monitored blood glucose levels. Dur- $3 h (221.2 6 44.0 mg/dL) afterward AcknowledgmentsNo potential conicts of
ing the 2012 BBT, 5,157 diabetic partic- (P , 0.05). The largest decrease followed interest relevant to this article were reported.
ipants (;90% insulin users) anonymously $30 min of exercise undertaken 1 h S.R.C. wrote the manuscript, contributed
entered exercise type, intensity, duration, (249.3 6 53.1 mg/dL) or 2 h (246.4 6 to the study design, and analyzed the data.
time elapsed since last meal, and blood 49.8 mg/dL) after eating (P , 0.001) com- M.J.H. contributed to the study design and
glucose readings before and after one or collected the data through the Diabetes Hands
pared with 30 min (234.3 6 53.5 mg/dL) Foundation. F.S. analyzed the data. S.R.C. is
more bouts of exercise separately through or $3 h (219.6 6 47.0 mg/dL). the guarantor of this work and, as such, had
www.BigBlueTest.org or an iPhone app. Although the 2012 BBT conrms that full access to all the data in the study and takes
Based on a prior BBT (1), exercise participation in varying types, intensities, responsibility for the integrity of the data and
choices were walking, running/jogging, and durations of exercise generally lowers the accuracy of the data analysis.
cycling, conditioning machines, dancing, blood glucose levels, engaging in just a 10-s Parts of this study were presented in
and other exercise (nonspecied). Inten- sprint before or after moderate activity abstract form at the 73rd Scientic Sessions
sity was moderate or vigorous. Duration can prevent a fall in glycemia in type 1 of the American Diabetes Association, Chicago,
was #10, 1119, 2029, or $30 min. diabetes because of a greater release of Illinois, 2125 June 2013.
The timing of exercise after the last meal The authors thank Andreina Davila, Emily
glucose-raising hormones from intense
was 30 min and 1, 2, or $3 h ago. Data Coles, and Emily Walton of the Diabetes
activity, suggesting that exercise varia- Hands Foundation, Berkeley, California, for
were reported as mean 6 SD. tions play a role in the expected response assistance in formulating the data collection
Walking was reported most fre- (2,3). However, most exercise that is lon- mechanisms for the BBT and collecting and
quently (48.5%), followed by other exer- ger in duration reduces blood glucose managing all the data.
cise (18.7%), running/jogging (11.9%), levels and may require regimen changes
cycling (8.8%), conditioning machines to prevent hypoglycemia (4). Because c c c c c c c c c c c c c c c c c c c c c c c c
(6.4%), and dancing (5.7%). Overall, 50 min of moderate exercise undertaken References
mean blood glucose levels were lower 60 or 180 min after breakfast carries a 1. Colberg SR, Hernandez MJ. The Big Blue
(231.3 6 47.1 mg/dL, 16.8%) after ex- similar risk of exercise-induced hypogly- Test: effects of 14 minutes of physical ac-
ercise, although only 75.8% decreased, cemia (5), the timing of exercise after tivity on blood glucose levels. Diabetes
Care 2013;36:e21
8.8% were unchanged, and 15.4% in- the last meal must be considered. In con- 2. Bussau VA, Ferreira LD, Jones TW, Fournier
creased. Walking resulted in the smallest clusion, varying types, intensities, and PA. A 10-s sprint performed prior to
decrease (225.0 6 42.4 mg/dL) com- durations of exercise generally lower moderate-intensity exercise prevents early
pared with nonspecied exercise blood glucose levels in most individuals, post-exercise fall in glycaemia in individu-
(233.5 6 50.0 mg/dL), running/jogging although exercise of longer duration is als with type 1 diabetes. Diabetologia
2007;50:18151818
3. Bussau VA, Ferreira LD, Jones TW, Fournier
PA. The 10-s maximal sprint: a novel ap-
Table 1Mean change in blood glucose levels (mg/dL) by exercise intensity and duration proach to counter an exercise-mediated fall
in glycemia in individuals with type 1 diabe-
tes. Diabetes Care 2006;29:601606
n #10 min 1119 min 2029 min $30 min 4. Zisser H, Gong P, Kelley CM, Seidman JS,
All exercise 7,157 217.9 6 44.9 225.0 6 34.4 230.9 6 42.0 234.5 6 51.7 Riddell MC. Exercise and diabetes. Int J
Moderate 5,051 216.9 6 43.8 225.6 6 32.9 229.9 6 40.2* 239.0 6 48.6* Clin Pract Suppl 2011;65(170):7175
5. Dub MC, Weisnagel SJ, Prudhomme D,
Vigorous 2,106 225.1 6 51.4 222.1 6 40.8 236.1 6 49.9* 227.6 6 55.5*
Lavoie C. Is early and late post-meal exer-
Data are mean 6 SD. For all exercise, all values differ from one another (P , 0.05). For moderate and cise so different in type 1 diabetic lispro
vigorous, *P , 0.001 vs. #10 min moderate, P , 0.001 vs. 1119 min moderate, P , 0.001 vs. 2029 min users? Diabetes Res Clin Pract 2006;72:
moderate, P , 0.001 vs. $30 min moderate, and P , 0.001 vs. 1119 min vigorous. 128134
care.diabetesjournals.org DIABETES CARE, VOLUME 36, OCTOBER 2013 e177
