Tuesday, December 15, 2009

How fast do running and swimming records drop with age?

Yale economist and marathon runner Ray Fair has analyzed record data in running and swimming to estimate the rate at which our ability drops with age.

As you see below, records decline at a relatively steady rate between the ages of 35 and 70-75, then the rate of decline picks up rapidly.

We see that distance running and swimming drop off faster than sprinting, and Fair notes that women drop off a bit faster than men. Chess declines are much slower than the physical activities.

Fair has calculated age factors like those graphed above for men running and high jumping, men and women swimming, and chess. For example, here are the age factors for short races -- 100, 200 and 400 meters -- by men:

Age factor1.

Using the table, you can see that if, for example, you ran 100 meters in 12 seconds at age 35, Fair would predict that you would have slowed to 1.23 x 12 = 14.8 seconds by age 70. (His tables use age 35 as a reference point).

If you have a time from an age other than 35, you can compute a predicted time using the ratio of the the two age factors. For example, if you ran a race in 20 seconds at age 50, you would expect it to take 20 x 1.23 / 1.09 = 22.6 seconds at age 70.

You can download a spreadsheet with all of Fair's age factors or use his online calculators to make your own estimates:This paints kind of a grim picture for me -- I am just turning 70 -- but there are a few "outs." For one, I spend more time weight lifting than running or swimming. I wonder what the age factors for weight lifting records are? A second possibility sounds like wishful thinking, but maybe record holders decline faster than the rest of us lesser athletes. Testosterone is another variable. To what extent are these results a function of diminished testosterone levels, and can testosterone supplementation slow the decline? (We have to talk about the efficacy and safety of testosterone supplementation in a later post).

Wednesday, November 25, 2009

How long can we expect to remain active and how acive can we remain? How fast will our capacity diminish with age?

I just read a blog post that takes a shot at working out:
A lot of people (boomers?) seem to be convinced that if they lift one more weight or run one more mile, they will never get old. Even if you don’t succumb to cosmetic surgery or spend too much money on expensive anti-aging creams that don’t work, there comes a day, I think, when it’s too much effort any longer to keep up the pretense.
Fear of aging and death are obviously not the only reasons we lift weights or run, but I'm not deluding myself that this will go on forever -- how long can we remain active and how active can we remain? How fast will our capacity diminish with age?

There is no comprehensive answer to these questions, but there are hints and anecdotes. For example, we can estimate the optimistic upper limit by profiling outstanding people of various ages. We can also analyze speed records and other performance measures as Alan Jones and his colleagues have done for running. And, although it may not be politically correct, we can look at the affect of drugs and supplements like testosterone -- do they slow our losses? Are they safe?

I will look at each of these -- unusually fit people, data analysis and drugs and supplements -- in future posts.

Saturday, November 14, 2009

One in eight people 65 and older exercise "vigorously" at least five days a week

According to a US Department of Health and Human Services report on the
Health Behaviors of Adults: United States, 2002–04 13.8% of people 65 and older exercise vigorously at least five days a week. A breakdown of the data shows that men are more likely to engage in frequent vigorous exercise than women and young people are more likely than old:

18-24 21.612 16.8
45–64 12.3 9.6 10.9
65-74 10.2 7.5 8.7
>=75 7.93.3 5.1

The authors of the 85-page report present other interesting data. For example, they found that the rate of vigorous exercise rises with income and education (which are correlated with age). They also observed differences based on race, region of the country, marital status and whether the respondent is from a metropolitan area, central city or smaller town.

The study defines a "vigorous" activity as one lasting at least 10 minutes and causing heavy sweating or large increases in breathing or heart rate.

Monday, August 17, 2009

Sore knees -- use them or lose them -- recovery time from an injury

I had a freak bicycle accident about ten weeks ago. For about four weeks, walking was quite painful and running impossible. I spent four weeks as a couch potato. I began walking after that, but then took a three week cruise. By the end of the cruise, I was able to walk fairly well, and had begun doing some upper-body weight lifting.

I began jogging about two weeks ago, and my legs were quite weak and my knees were stiff and sore. I had expected to be weak, but was surprised by the pain and stiffness in my knees. I had assumed they would have benefited from the rest, but was completely wrong. It is as if some lubricant had dried up as a result of inactivity. There seems to be some feedback mechanism -- perhaps hormonal -- that "decided" I was old and would not be using my knees any more.

After about two weeks of jogging, shooting baskets and doing leg presses, my knees feel about the same as they did before the accident. (I am still weaker than before, but improving).

My knees came back faster than my leg strength, but this seems to be a clear case of use it or lose it.

Short term effects of fatty foods

Everyone knows that a fatty diet causes one to gain weight, form arterial plaque, etc. However, new research shows that fatty foods have a short term effect -- adversely affecting both memory and the ability to exercise.