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.