Stay­ing phys­i­cally ac­tive helps you keep healthy in later years, study says

Miami Herald - - FRONT PAGE -

Be­ing a world-class dis­tance run­ner in your youth does not guar­an­tee you will be fit and healthy in re­tire­ment. But it helps, ac­cord­ing to a study that fol­lowed a group of elite U.S. run­ners for 45 years.

The study’s find­ings raise in­ter­est­ing ques­tions about how we can and should age and the role that youth­ful ac­tiv­ity might play in our health later in life.

Ag­ing is a great mys­tery of life and sci­ence. Its chronol­ogy is clear: With each pass­ing year, we are a year older. But the bi­ol­ogy of the process is murky. Sci­en­tists re­main un­cer­tain about how and why our bod­ies change as we age and to what ex­tent such changes are in­evitable or mu­ta­ble.

In other words, we do not know whether ag­ing as most of us now ex­pe­ri­ence it is nor­mal for the hu­man species or not.

That is­sue is at the heart of the new study, which was pub­lished this month in Medicine & Sci­ence in Sports & Ex­er­cise. It be­gan al- most 50 years ago, with a spate of coach­ing and test­ing that took place be­fore the 1968 Sum­mer Olympic track and field tri­als in the United States. Jack Daniels, an ex­er­cise phys­i­ol­o­gist and run­ning coach, be­gan work­ing with some of Amer­ica’s top dis­tance run­ning prospects. He tested 26 ath­letes ex­ten­sively, de­ter­min­ing their aer­o­bic ca­pac­ity, or VO2 max, and other mea­sures of health and per­for­mance ca­pa­bil­ity.

All of the run­ners, who were in their early to mid-20s, had aer­o­bic ca­pac­i­ties at or above the 98th per­centile for men of their age. Sev­eral won Olympic medals.

Twenty-five years later, in 1993, cu­ri­ous to see how the ath­letes’ bod­ies had changed, Daniels, a pro­fes­sor of ki­ne­si­ol­ogy at A.T. Still Univer­sity in Mesa, Ariz., as­sem­bled the same group at a hu­man per­for­mance lab and tested them again. In 2012, he men­tioned this trove of un­pub­lished data to his col­league Sarah Ever­man, an as­sis­tant pro­fes­sor of ki­ne­si­ol­ogy at the univer­sity.

In­trigued, Ever­man sug­gested bring­ing the ath­letes back to the lab again. Twenty-two of the men, who by this time were in their late 60s or early 70s, agreed to par­tic­i­pate when she con­tacted them the next year, by then 45 years af­ter their orig­i­nal test­ing. (Three had died since 1993, and one de­clined to be tested again.)

At the lab, the re­searchers ran the men through the same tests as be­fore and asked about ex­er­cise rou­tines. They found that, although the men re­mained phys­i­cally ac­tive and gen­er­ally ex­er­cised a few hours each week, none were still com­pet­i­tive ath­letes.

But their fit­ness re­mained rel­a­tively out­sized, she found. Each man’s VO2 max had de­clined sig­nif­i­cantly since 1968, when he was in his 20s and com­pet­ing, and also since the sec­ond test­ing in 1993. But their 2013 VO2 max num­bers still placed them in the top 10 per­cent or so of older U.S. men, based on ta­bles de­vel­oped in re­cent years us­ing car­dio­vas­cu­lar test­ing data from thou­sands of ag- ing peo­ple. These find­ings might in­di­cate that the for­mer ath­letes were ge­net­i­cally gifted, Ever­man says. They might be phys­i­o­log­i­cal out­liers whose lucky car­dio­vas­cu­lar quirks lin­gered into old age and al­lowed them to re­main un­usu­ally fit in com­par­i­son to other older peo­ple.

But she is skep­ti­cal of that read­ing. Numer­i­cally, the men’s VO2 max lev­els de­clined more dur­ing the 45 years of the study, she says, in the per­cent­age of the ca­pac­ity they lost per decade, than con­sid­ered nor­mal, based on data from nonath­letes.

But they were de­clin­ing from such a height of fit­ness that, even as their ca­pac­i­ties con­tracted, the men’s fit­ness stayed above av­er­age, she says.

Such data sug­gest that squir­rel­ing away fit­ness when we are young with sus­tained, fre­quent ex­er­cise might help to blunt some of the losses later, she says.

But the study’s broader mes­sage, she says, could be that we may need to re­think what nor­mal fit­ness is or should be in older peo­ple. The ta­bles that doc­tors and other ex­perts use to de­ter­mine “nor­mal” fit­ness have been con­structed with data gath­ered from typ­i­cal older peo­ple today, many of whom have been seden­tary for years.

These men’s lives sug­gest that greater fit­ness is pos­si­ble in old age, even for those of us who were not pre­vi­ously Olympians, Ever­man says. “These guys were not train­ing hard” by the time they be­came sep­tu­a­ge­nar­i­ans, she says, and most al­ready had eased back con­sid­er­ably in their work­out rou­tines by the 1993 test­ing, she says, when they were mid­dle-aged.

But they never stopped ex­er­cis­ing al­to­gether, ex­cept dur­ing pe­ri­ods of ill­ness or in­jury. If the rest of us fol­lowed a sim­i­lar work­out tra­jec­tory dur­ing our lives, she says, we might wind up with a higher VO2 max than oth­er­wise in our old age, re­set­ting both our ex­pec­ta­tions about agere­lated fit­ness and the ex­ist­ing ta­bles.

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