Brief, Hard Workout Does the Trick

Blood glucose level improved equally between short high intensity sessions and longer moderate exercise

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Sometimes it seems that there are not enough hours in the day to make time for exercise. But a short, intense workout may be enough for some diabetes patients.

New research showed that exercising hard in short, intense spurts improved blood glucose (sugar) levels as much as longer, less intense exercise among both diabetics and non-diabetics.

The quickness and intensity of the exercise can help people achieve the same result in a shorter amount of time.

"Short on time? Work out hard!"

Researchers under the direction of Peter Adams, deputy dean from the Faculty of Medical Sciences at the University of the West Indies in Barbados, looked at how brief, high-intensity exercise affected blood glucose levels in people with and without diabetes.

The researchers reviewed 14 previous studies covering more than 60 diabetic and non-diabetic individuals.

Within the non-diabetic studies, exercise time varied between seven and a half to 40 minutes of high-intensity exercise a week for a number of weeks.

Researchers found that the brief, high intensity exercise improved blood glucose for one to three days after exercise in both diabetics and non-diabetics.

One study involved sprint interval training and testing insulin sensitivity in people without diabetes. Interval training alternates sprinting with a less strenuous exercise. Insulin sensitivity is a measure of how the body processes glucose for energy.

In people with diabetes, glucose isn't processed properly and results in too much glucose floating in the bloodstream. This "high blood sugar," as it's often called, can cause fatigue, hunger and pain around the body.

Results showed that after two weeks of sprint interval training, insulin sensitivity increased as long as three days after the exercise among non-diabetics.

In other studies, researchers compared short, high intensity exercise with longer, moderate intensity exercise in which participants worked out 65 percent as hard as they could for two and a half hours each week.

Researchers found that the improvements in participants' blood glucose levels from high intensity exercise were similar to improvements seen in those who moderately exercised over the longer period of time.

Among type 1 diabetics, blood glucose decreased from midnight to early morning after high intensity exercise the previous morning.

For type 2 diabetics, a single exercise session improved blood glucose levels for 24 hours.

Over a longer period of time, type 2 diabetics in a two-week high intensity exercise program reduced their average blood glucose levels by 13 percent at two and three days after the workout.

"From a purely experimental view of high intensity workouts vs. our client's body composition we have found outstanding progress from a high intensity protocol of workouts," said Jim Crowell, owner and trainer of Integrated Fitness and dailyRx Contributing expert.

"We also see our client's lose unnecessary weight and body fat far faster when they utilize a training regiment like this vs. a traditional weight lifting 'reps and sets' being done separately from cardiovascular workouts."

As quick and efficient as high-intensity exercise seems to be, researchers noted that the exercise may not work as well across all participants.

"However, the perceived exertion associated with the 'all out' version of high intensity exercise is very high and the acceptability, feasibility, and safety for the sedentary diabetic and non-diabetic population are in doubt," the researchers wrote in their report.

"Both the risks of musculoskeletal injury and cardiovascular complications have to be considered," they wrote.

The researchers said that the effectiveness of high intensity exercise programs over the long term should be considered in future studies.

The study was published February 27 in the journal Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. No conflicts of interest were reported.

Reviewed by: 
Review Date: 
March 4, 2013
Last Updated:
August 15, 2013