RESEARCH NEWS

A small study of obese children appears to show cells in bone, fat and the pancreas communicate with each other during and after exercise.

Analysis of the children showed that a 12 week after- school programme of vigorous exercise resulted in stronger bones, improved insulin sensitivity (reduced diabetes risk) and less of the most- deadly belly, or visceral, fat.

Researchers lead by bone biologist Dr Norman Pollack at the Georgia Health Sciences University in America also found that blood levels of the hormone osteocalcin, made by bone-producing osteoblasts, might be a good indicator of

Exercise can produce healthy chatter in your body

how things are developing in all three areas. Osteocalcin levels have been primarily associated with bone growth but it is only recently that scientists are making a link with it and improved insulin sensitivity, less belly fat and denser bones.

Dr Pollack explains: “The idea is that bones can possibly sense environmental stimuli such as being physically active or sedentary and dictate energy regulation accordingly. The reality is bones get bigger and stronger with exercise and they appear to

be sharing the good news.

“When osteocalcin is released in your blood, that hormone is talking back to the adipocytes, the cells that store fat, and the pancreatic cells that release insulin to improve energy metabolism.”

Bone researchers like Pollock have previously believed bones were just listening. His study looked at children who were inactive as well as those who exercised 20 or 40 minutes daily. Pollock notes that bone and

fat cells do have a common ancestry: they are both derived from mesenchymal stem cells. “It’s possible that children’s early lifestyle habits and experiences may induce alterations in body composition and predispose them to a lifetime of obesity,” he said.

“As parents, we must ensure that our children balance out their screen time with enjoyable physical activity.” http://bit.ly/ogcr6B

How the right exercise can make a 50-year-old as fit as a 20-year-old

New research from the Norwegian University of Science and Technology’s K.G. Jebsen Center of Exercise in Medicine provides statistical evidence that 50-year-olds can be every bit as fit as someone 30 years younger. But exercise - how much, and how intense - is the key.

The study shows that by increasing the intensity of your exercise, you can beat back the risk of metabolic syndrome, the troublesome set of risk factors that can predispose people to type 2 diabetes, stroke and cardiovascular problems.

“Physical condition is the most important factor in describing an individual’s overall health, almost like a report card,” says Stian Thoresen Aspenes, who was recently awarded his PhD by NTNU for his research conducted at the K.G. Jebsen Center.

When the Jebsen Center researchers looked at the importance of the intensity of exercise versus the duration, intensity was far more important than duration in determining peak oxygen uptake.

They also looked at the benefits of high intensity exercise in the form of interval training -- where four or more short periods (typically 4

10

minutes) of very high intensity exercise are followed by a similar number of short periods of lower intensity exercise. This approach, called 4x4 interval training, is a quick way to increase your overall fitness, research from the Jebsen Center has confirmed.

Researchers found that women whose fitness values were below the median VO2peak (<35.1 mL kg-1 min-1) were five times more likely to have a cluster of cardiovascular risk factors compared to those in the highest quartile of VO2peak (40.8 mL kg-1 min-1). For men below the median (<44.2 mL kg-1 min-1), the risk was even higher -- they were eight times more likely to have a cluster of cardiovascular risk factors compared to those in the highest quartile of VO2peak (50.5 mL kg- 1 min-1). Even small differences in VO2peak were found to be associated with worsening cardiovascular risk profiles.

The centre’s research shows that maintaining some level of physical activity is important. The benefit from having been active when young is small if you are inactive now. “Even if you were highly active at a young age, you have to keep being active to get the health benefits from it,” says Professor Wisloff. http://bit.ly/o1CKMb

The REPS Journal 2011;23(January):10-11