We all know that diet and exercise are critical to good health. This dynamic duo has been shown to ward off obesity, diabetes, joint issues, cancer and heart disease.
We can even agree, for the most part, on the diet bit. We know that fruits, vegetables, lean proteins, wild-caught fish and whole grains should be the mainstay. We know that trans-fat and too much sugar are bad.
But what about exercise? How much? How often? What kind? While some of those answers depend upon your health and/or fitness goals, Swedish researchers say just 30 minutes a day should do the trick. And all you have to do is walk.
Give Me Thirty…
Researchers divided 33 adults into two groups. The first group was asked to walk briskly for 30 minutes every day for three weeks. The second group did not do any exercise during the three-week period.
In addition to noting participants’ weight and BMI, both groups also had blood taken at the start and end of the test period. Researchers found that those people who exercised daily enjoyed a significant drop in their LDL cholesterol, as well as their total cholesterol. They also found that the greater the participants’ energy expenditure (i.e., how many calories they burned during exercise), the greater their weight loss and BMI.
Researchers concluded that simply walking briskly for 30 minutes a day had beneficial effects on cholesterol levels.
So, if exercise can help you reduce your cholesterol levels, can it help them from becoming elevated in the first place? Or, better yet, can exercise protect cholesterol from oxidation?
When Cholesterol Goes Bad
People who are overweight tend to not just have elevated cholesterol, but that cholesterol is often oxidized. See, it’s the oxidation that is the real issue when it comes to heart disease.
Cholesterol in and of itself isn’t bad. Not even the often-maligned LDL cholesterol. In fact, it’s quite critical for many bodily functions, including hormone production. What makes it “bad” is oxidation.
To give you a couple of everyday examples, think of rust on your car or that fresh fruit salad that has just turned brown. It’s not that the bumper was bad or your apples were rotten. It’s that they became oxidized. Ditto for cholesterol.
So the question then becomes, short of losing weight, how does someone who is overweight protect themselves from high and/or oxidized cholesterol?
Can Heavy Be Healthy?
Finnish researchers were pondering a similar question. If exercise can lower cholesterol, can it protect overweight or even obese individuals from developing unhealthy cholesterol levels?
To answer this, they divided 831 healthy men ages 18 to 48 into three groups based on their BMI. Fifty-eight percent of the group fell into the “normal” range (BMI of 18.5 to 24.9). Thirty-two percent were in the “overweight” range (BMI of 25 to 29.9). The remaining nine percent were found to be obese (BMI of 30 or greater).
Next, researchers tested each participant’s fitness level, both cardio and strength. For the cardio, they used a stationary bike, increasing the difficulty every two minutes until exhaustion.
To test muscle strength, participants had to do four sets of exercises:
- Grip strength
- Repeated squats
Participants did as many exercises as they could in 60 seconds for each of the individual tests. Researchers then ranked participants according to fitness level, noting if they were unfit, average or fit.
Finally, after an overnight fast, all participants were weighed and had blood taken. Researchers calculated BMI and noted several lipid factors:
- LDL cholesterol
- Oxidized LDL cholesterol
- HDL cholesterol
- Total cholesterol, and
- Ratio of oxidized LDL to HDL cholesterol
After gathering all of this information, researchers found a few surprises.
Exercise is Truly Cardio-Protective
Let’s first look at the parts that weren’t shocking. Fitness levels were lower in those groups with higher BMI. Those same men also had higher oxidized LDL, higher total cholesterol and triglycerides, lower HDL, and higher oxidized LDL to HDL ratio.
On the cardio front, those who were overweight and had low cardio fitness had higher oxidized LDL, higher total cholesterol, higher LDL and triglycerides, lower HDL, and a worse oxidized LDL to HDL ratio than their normal weight counterparts.
And you can guess how it went when researchers compared overweight men who were fit to average men who were fit. Their profiles were worse, especially when it came to oxidized LDL, triglycerides, and the oxidized LDL to HDL ratio.
On the muscle strength side, the story was much the same. Overweight men with low muscle strength had higher oxidized LDL, higher total cholesterol, higher LDL and triglycerides, lower HDL, and a worse oxidized LDL to HDL ratio than their normal weight counterparts who also rated lower on muscle strength.
It wasn’t much different when you compared overweight, average strength guys to their normal weight peers. The overweight group had higher LDL and triglycerides, lower HDL, and worse oxidized LDL to HDL ratios.
When both groups were deemed fit from a muscle strength standpoint, the overweight group still fared slightly worse, showing lower HDL levels and worse oxidized LDL to HDL ratio than the average weight participants.
Of course, it was similar when they compared overweight fit men to overweight unfit men. Those that were fit had better readings.
All seems pretty much as expected, right? But that’s not all the researchers discovered.
Turns out, there were no differences in cholesterol readings between overweight men and normal men when both groups were deemed fit from a cardio standpoint.
Additionally, there was no difference in oxidized LDL levels or total cholesterol in normal weight men who were fit and overweight men who were fit, both in muscle strength and cardio ability.
Researchers concluded, “Good cardiorespiratory and muscular fitness seem to protect overweight subjects from the atherogenic lipid profile.”
It’s Never Too Late to Start
What both of these studies show is that exercise, particularly aerobic, helps lower cholesterol levels and keep those levels in check.
As the Swedish study shows, just 30 minutes a day should do the trick on the cardio front. If you are new to exercise, add push-ups, sit-ups, squats and bicep curls to start to get some overall body strength. Aim for two to three sets of 10 each.
It shouldn’t take more than 45 to 60 minutes to complete your entire workout. Just think, that hour you spend today could save you in the future.
 Pagels, P et al. Influence of moderate, daily physical activity upon body composition and blood lipid profile in Swedish adults. J Phys Act Health. 2011 Sep 13.
 Kosola, J et al. Good aerobic or muscular fitness prevents overweight men from elevated oxidized LDL. Med Sci Sports Exerc. 2011 Sept 19.