The Charter ( Medical Professionalism in the New Millennium.A Physician's Charter) did not deal with just the important relationship of ...
Monday, October 10, 2016
Exercise capacity of octogenarians and age related decline in exercise capacity
A great source for information about the exercise capacity of octogenarians is a 2013 article by Scott Trappe and co-authors.( Trappe,S et al , New records in aerobic power among octogenarian lifelong endurance athletes. JAAP, vol 114, no 1, 3-10.) See here.
The authors studied 9 life long and still competitively active elite endurance athletes and compared their aerobic capacity as well as myocellular markers of oxidative metabolism with 6 age matched healthy non exercisers.
The V02 max (maximal oxygen uptake ) in the group of athletes was 38 plus/minus 2.1 ml/kilo/minute versus 21 plus minus 1 for the sedentary group. The authors reviewed other published data on aerobic capacity in untrained 80 year olds and found:
1) In 195 men the average V02max was 21 plus/minus 4
2) In 269 women the average V02max was 18 plus/minus 4
These values are comparable to Trappe's non-exercising subjects while his athletes were said to have the highest values reported in a group of octogenarians.(There are some individual case reports with value this high and higher-see below)
Having monitored several hundred stress tests using the Bruce protocol I find it helpful to put these 02max values in that context.
The Bruce protocol has 3 minutes stages and after each the treadmill pace and inclination increase:
Stage I 1.7 mph 10% grade using 5 METS and requiring 17.5 ml 02/kilo/mi
Stage II 2.5 mph 12% 7 METs 24.5
Stage III 3.4 mph 14% 9 METS 31.5
Stage IV 4,2 mph 16% 13 METS 45
Stage V 5 mph 18% 15 Mets 52
Stage VI 5,5 mph 20% 18 METS 68
A MET is the resting oxygen uptake of 3.5 ml 02/kilo/min.
Based on these values many or maybe most of the male non athlete octogenarians would complete Stage I while a number of the females might not not.Most of Trappe/s athletes would complete Stage 111 .
One of Trappe 's'subjects was 91 years old , a former Olympic champion ( ok he is not an octogenarian) has an amazing aerobic capacity of 36! He should complete stage 3 and into stage 4.
Using time estimates from Tim Noakes book (footnote 1 ) you can guesstimate running and marathon times from aerobic capacity or at least get a estimate of the aerobic capacity that is required to run at a given speed. An 02 capacity of 30-32 would be required to complete the 26.2 marathon in about 5.5 hours.
Ed Whitlock, dob 1931, was the first man to run a marathon in less than 3 hours at age 70 .At age 73 he ran a 2:54 marathon.It probably takes a 02 Max of 60 to run a sub three hour marathon.
There are real life 80 year people who complete marathons. For example, 4 men all aged 80 finished the Houston Marathon in times ranging from 4:23 to 5:40 in 2016 .The winner in this group probably has a 02 max of about 40 ( using the table from footnote 1).Also there were three 80 year olds who completed the NY City Marathon in 2016 with times ranging from 5:03 to 5:37.
In 2011 Ed Whitlock at age 80 ran the Toronto Marathon in 3:15corresponding to a 02 uptake of 50-53. This is comparable to the report by Trive Karlsen who measured the max 02 uptake on an 80 year old Norwegian at 50 and claimed a world record for an 80 year old.See here. There are a few other octogenarians who have run a sub-four hour marathon, Ed Benham ran 3:48 at age 82. and Harold Willson who did 3:58 at age 80 . These are times probably requiring an 02 Max of around 40.
(See addendum below for update on Ed Whitlock)
In regard to the non superathlete male octogenarians , their average 21 ml/kilo/min aerobic capacity should allow them to be able to walk at a fifteen minute per mile pace ( which is a fairly brisk walking pace) which probably requires about 17 ml 02/kilo/min as does playing double tennis, doing light yard work ,etc. and a lot more than whittling on the park bench.Finishing Stage II suggests adequate 02 capacity to run a fifteen mile. (Walking a fifteen minute mile requires about 70% as much 02 uptake as does running a mile.)
It seems more than reasonable to assume that these octogenarian marathon finishers has in their youth 02 max values just as impressive for their ages then as they are now and likely could have run a marathon in less than 2 1/2 hours.
The conventional thinking is that from about age 45 to age 70 a persons aerobic capacity declines somewhere between 5% and 10 % per decade. Some studies have shown and other studies have presented contradictory evidence that those who continuously train aerobically have a lower rate of decline. ( Personal note-A rough calculation based on my marathon times suggest that my decline was slightly over the 10% per decade number)
Some of subjects in the non athletic group had V02 max value approaching the range that have been proposed as a threshold value for independent living(18 ml/kilo/min) and as a threshold for disability assessment ( 15 ml/kilo/min) refs 2 and 3
The lower the 02 max, the higher percentage of it is used for the typical activities of everyday life leading to fatigue and predisposition to inactivity and deconditoning. Further the increased oxygen consumption attendant to trauma , acute illness and surgery may push someone with a 18 -20 02 max over into the disabled category .
addendum: 10/19/2016- Ed Whitlock, now 85 years old, finished a marathon In Toronto in 3 hours and 56 minutes -over a half hour quicker than the previous record for that age for the marathon.
1.Table 2.3 page 66, Forth Edition of "Lore of Running " Tim Noakes
2 Jackson, AS et al Effect of lifestyle and aging on the longitudinal change in respiratory fitness. Arch Int Med. 2009,169 ,1781
3 Putz, C et al Incremental shuttle and six minute waking tests in the assessment of functional capacity.in Chronic Heart Failure.Can J Cardiol 2008 24 (2) 131-134