Tag Archives: fitness

Food-Based Body Clock the Key to Jet Lag

The primary cause of jet lag (or desynchronosis as it’s correctly known) is the disruption of our circadian rhythms based on the daily light–dark cycles we experience. However this is only the case when food is in plentiful supply, with new research suggesting that circadian rhythms based on food availability are able to override those of the light-dark cycle. This could offer us a simple and effective way of preventing jet lag: fasting for sixteen hours prior to your new time zone’s breakfast time.

I mentioned this in passing two years ago (just before undertaking a 25-hour Sydney to London flight), but after recently coming across the study again I felt compelled to point to it in more detail.

Researchers at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston have now pinpointed a second [biological clock] that is set by the availability of food. […]

Clifford Saper, the senior author of the study, said this second clock probably takes over when food is scarce. It may have evolved to make sure mammals don’t go to sleep when they should be foraging for food to stay alive.

Dr. Saper says long-distance travellers can probably use this food clock to adjust rapidly to a new time zone.

“A period of fasting with no food at all for about 16 hours is enough to engage this new clock,” he said in a statement released with the study. Once you eat again, your internal clock will be reset as though it is the start of a new day […] and you should just flip into that new time zone in one day.

Sedentary Lifestyle? Exercise Isn’t Helping

A somewhat sedentary lifestyle combined with regular exercise is turning us into what physiologists are calling ‘active couch potatoes’–and that exercise, no matter how vigourous, doesn’t appear to be counteracting the negative effects of that sedentary lifestyle.

In rats, this lifestyle was found to produce “unhealthy cellular changes in their muscles” and increase insulin resistance and fatty acid levels in their blood. In conclusion: a mostly sedentary lifestyle is bad for us, regardless of exercise habits.

[Studies have shown] that, to no one’s surprise, the men who sat the most had the greatest risk of heart problems. Men who spent more than 23 hours a week watching TV and sitting in their cars (as passengers or as drivers) had a 64 percent greater chance of dying from heart disease than those who sat for 11 hours a week or less. What was unexpected was that many of the men who sat long hours and developed heart problems also exercised. Quite a few of them said they did so regularly and led active lifestyles. The men worked out, then sat in cars and in front of televisions for hours, and their risk of heart disease soared, despite the exercise. Their workouts did not counteract the ill effects of sitting. […]

Decades ago, before the advent of computers, plasma TVs and Roombas, people spent more time completing ‘light-intensity activities’ […] Nowadays, few of us accumulate much light-intensity activity. We’ve replaced those hours with sitting.

The physiological consequences are only slowly being untangled. […] Scientists believe the changes are caused by a lack of muscular contractions. If you sit for long hours, you experience no ‘isometric contraction of the antigravity (postural) muscles’. […] Your muscles, unused for hours at a time, change in subtle fashion, and as a result, your risk for heart disease, diabetes and other diseases can rise.

via Waxy

More on the Cognitive Benefits of Moderate Exercise

“There is overwhelming evidence that exercise produces large cognitive gains and helps fight dementia”, says the Harvard University psychologist John Ratey, author of the 2008 book on the subject, Spark.

While Ratey propounds the “very clear” link between exercise and mental acuity, saying that even moderate exercise pushes back cognitive decline by “anywhere from 10 to 15 years”, the National Institutes of Health are more cautious:

Looking at reducing the risk of “cognitive decline in older adults,” [the NIH] wrote: “Preliminary evidence suggests a beneficial association of physical activity and a range of leisure activities (e.g., club membership, religious services, painting, gardening) with the preservation of cognitive function.” A few small studies showed that “increased physical activity may help maintain or improve cognitive function in normal adults”.

I’ve written before about the extensive cognitive benefits of exercise, but as Noah Gray (via) says, “it never hurts to reinforce the message”.

Assorted Health and Fitness Tips from a Veteran Trainer

After years as a trainer, Mike O’Donnell compiles and shares an extensive list of health and fitness tips.

As Jason said, there’s “a lot of good (and questionable) stuff in this list”. Here are my favourites:

  • Diet is 85% of where results come from… for muscle and fat loss. Many don’t focus here enough.
  • If you eat whole foods that have been around for 1000s of years, you probably don’t have to worry about counting calories.
  • The eat low-fat advice was the biggest health disaster in the last 30 years.
  • The smartest trainer I know does not have a website or best selling ebook… as he is too busy training real clients. (Related.)
  • If you want to get better at running… you run… at biking… you bike… at a sport… you play that sport.
  • There is no one right way for anything… as 20 different ways can get you results.
  • Results are just the simple yet important things done on a consistent basis.
  • All diets fail over the long run….but lifestyle changes last.
  • The best thing anyone can do for their health/results is to just try new things… see how their body adapts and responds… and learn how to take total control no matter life may throw at them in the future.

via Kottke

Health and Alcohol Intake (Men, Women, Wine)

A longitudinal study of almost 20,000 U.S. women is showing signs that moderate alcohol consumption (“one or two alcohol beverages a day”) can lower the risk for obesity and inhibit weight gain:

Over the course of the study, 41 percent of the women became overweight or obese. Although alcohol is packed with calories (about 150 in a six-ounce glass of wine), the nondrinkers in the study actually gained more weight over time: nine pounds, on average, compared with an average gain of about three pounds among regular moderate drinkers. The risk of becoming overweight was almost 30 percent lower for women who consumed one or two alcohol beverages a day, compared with nondrinkers. […]

The link between consumption of red wine and less weight gain was particularly pronounced. […] Some studies have suggested that resveratrol, a compound present in grapes and red wine, appears to inhibit the development of fat cells and to have other antiobesity properties.

The article also notes that while moderate alcohol consumption has been associated with “better heart health”, it has also been associated with an increase in breast cancer risk.

None of this is good news for men:

Studies suggest that drinking alcohol has different effects on eating habits among men and women. Men typically add alcohol to their daily caloric intake, whereas women are more likely to substitute alcohol for food. […]

In addition, there may be differences in how men and women metabolize alcohol. Metabolic studies show that after men drink alcohol, they experience little if any metabolic change. But alcohol appears to slightly speed up a woman’s metabolism.

As before: this is still correlatory, but interesting nonetheless.