Thanks for this interesting thread.  Just to jump in the fray as a working exercise physiologist who keeps up with the research...I agree with John on several fronts; especially on what the European Heart Journal article actually reports.  The manuscript shows there are increased cases of atrial fibrillation and bradycardias in long distance XC skiers, but showed no association with death in this very large cohort.  The standard has been to believe in the standard U shaped curve with sedentary behavior and extremely high level of exercise showing a similar risk of mortality, but my opinion is that recent evidence has discredited this notion.  


Christine Mermier
(UNM Exercise Physiology lab)

From: Bike-racers <bike-racers-bounces@mailman.swcp.com> on behalf of John Vance via Bike-racers <bike-racers@mailman.swcp.com>
Sent: Monday, October 22, 2018 3:49:27 PM
To: perlsbob@gmail.com
Cc: Bike Racers
Subject: Re: [NMCycling] For health benefits, there is no upper bound on aerobic exercise
 
So, I found this: https://academic.oup.com/eurheartj/article-pdf/34/47/3624/17354170/eht188.pdf

The overall risk of arrythmias was 18 cases per 10,000 years at risk.  The hazard ratio for the fastest or most frequently competing was 1.3.  The endpoint was not death, but rather cases of arrythmia.  There was NO association found with cases of cardiac arrest or sudden cardiac death vs frequently competing or being a faster finisher. 

> We did not observe higher incidence of sudden cardiac death with higher number of completed races or finishing time, but again it must be stressed that this study does not compare with the normal population. We have previously shown that participants in Vasaloppet have lower mortality than the general population and that mortality decreases with increasing number of races.

On Mon, Oct 22, 2018 at 12:52 PM Bob Perls <perlsbob@gmail.com> wrote:
I will look at it for sure, interesting.  But it is not about elite vs. not elite, rather intensity and duration over many decades.  Perfect correlation of higher finishers in 50km XC skiing events and death by MI for Sudden Cardiac Death (arrhythmias).  In other words, the more you train and the more intense the training over decades for long endurance events, the greater the likelihood of death.  A classic inverted U shaped curve where about 3 hours in  duration seems to be the longest average training and racing sessions ought to be.  These studies were self-reported, rather end points were death.

If this study contradicts this previous data, should be interesting.

Bob Perls
www.unitenm.us









On Oct 22, 2018, at 12:27 PM, John Vance <adogapanicinapagoda@gmail.com> wrote:

This study, unlike previous ones, measured fitness objectively with a treadmill test instead of basing it on self reporting.  This eliminated the people who count 3 hours of house cleaning and personal care as exercise.  Their "elite" level subjects were people capable of 5 to 6 minute miles, and they showed continuing mortality improvement all the way up to these elite performers

The link to the actual study is in the first paragraph.  Look at the size of effect - it's huge from low fitness to elite.  It's still significant between high fitness and elite.  Look at Table 2 for the fitness cutoffs measured in METs.

On Mon, Oct 22, 2018 at 12:10 PM Bob Perls <perlsbob@gmail.com> wrote:
Certainly “The Haywire Heart” written by an electrophysiologist and a cycling coach indicates that 3 hours seems to be the break point beyond which repeated high level efforts result in diminishing marginal gains and probably has an adverse effect long term on mortality and morbidity.

Bob Perls
www.unitenm.us









On Oct 22, 2018, at 11:42 AM, John via Bike-racers <bike-racers@mailman.swcp.com> wrote:

Viewed an interesting Ted Talk about how High Intensity/Competitive training can cancel out any gains made to longevity.  Seems moderation is key or until the next study comes out….   
 
 
 
From: Bike-racers <bike-racers-bounces@mailman.swcp.com> On Behalf Of John Vance via Bike-racers
Sent: Monday, October 22, 2018 11:17 AM
To: Bike Racers <bike-racers@swcp.com>
Subject: [NMCycling] For health benefits, there is no upper bound on aerobic exercise
 
 
There are two takeaways from this study.  First, being inactive really is deadly, and second, there is no risk associated with the levels of exercise we engage in.  In fact, health benefits continue to increase the more you exercise:
 
>There does not appear to be an upper limit of aerobic fitness above which a survival benefit is no longer observed. These results are in concordance with previous observational studies35-38 of highly active cohorts and other large, longitudinal studies4,6 of CRF and mortality but are notably discrepant from population-based studies24-26 of physical activity and exercise. This difference may reflect the objective measurement of physical fitness in the present study, as opposed to self-reported activity levels, which have been a major limitation of prior studies.
_______________________________________________
Bike-racers mailing list
Bike-racers@mailman.swcp.com
https://mailman.swcp.com/cgi-bin/mailman/listinfo/bike-racers