Now, it’s not exactly shocking news to hear that exercise is good for you. It’s been clearly demonstrated that 30 minutes of exercise helps you lose and maintain weight, reduce the risk for heart disease, ease depression, and even fend off Alzheimer’s.
But, did you know that the type of exercise might be the key?
Walk for Heart, Lift for Diabetes
In a recent study from Atherosclerosis,1 researchers tested the effects of both aerobic and resistance (or strength) training exercise in overweight and obese participants. They were broken into four groups:
- Group 1: Control group (no exercise)
- Group 2: 30 minutes of moderate walking
- Group 3: 30 minutes of resistance training (8-12 reps of 5 exercises, up to 10 times each)
- Group 4: Combination of 15 minutes walking and 15 minutes resistance training
Participants were then given a high-fat meal about 14 hours after the exercise. Researchers found that 30 minutes of walking reduced triglyceride levels better than resistance training or combined training. Additionally, they found that resistance training decreased insulin levels by 30 percent and was much more effective than walking.
Interestingly, they also noted that none of the exercise options helped improve blood pressure (as determined by pulse wave analysis). It is this finding that raised a few eyebrows and caused some challenges in the medical community.
Exercise Doesn’t Reduce Blood Pressure?
In a letter to the editor of Atherosclerosis,2 several researchers explore this exercise/blood pressure relationship a bit more closely.
Previous studies by the group had found that 30 minutes of continuous aerobic exercise, as well as three 10-minute intervals, not only reduced triglyceride levels in both young and middle-aged obese men, but also reduced triglycerides AND blood pressure levels in healthy young males.
They also point out two additional studies that showed an improvement in blood pressure markers (pulse wave velocity) in healthy people who did aerobic exercise. In both of these studies, the post-meal testing was done the same day as the exercise, while in the initial study, it was done 14 hours after exercising.
Based on this, the reviewers agreed that the improvements in blood pressure markers after exercise is likely short-lived.
My Humble Take
What surprises me the most is that the researchers didn’t point out the state of health of the participants involved. Comparing overweight and obese individuals to either healthy individuals or those already exercising seems like comparing apples and oranges.
Still, there appears to be no disagreeing with the fact that aerobic exercise and strength training help reduce your risk for heart disease and diabetes. Which means …
Based on these studies, as well as the myriad that have preceded them, exercise should not be an option. You need a healthy blend of both aerobic exercise and strength training to get and stay in optimal health.
And, as the studies showed, walking is a great option. If you want to kick it up a notch, you can run, take an aerobics class, bike, swim, even dance. The key is to just MOVE for 30 minutes four to five days a week.
As for strength training, you can take a class at your local gym, work with a trainer, get an exercise DVD, or even do a yoga class, which combines stretching with strength training. Again, aim for 30 minutes a day, three to four days a week.
1Ho, SS et al. Acute exercise improves postprandial cardiovascular risk factors in overweight and obese individuals. Atherosclerosis. 2011 Jan. 214(1):178-84.
2Miyashita, M et al. The effects of 30 min of exercise on cardiovascular disease risk factors in healthy and obese individuals. Atherosclerosis. 2011 Feb 22. [Epub ahead of print].