December 15, 2022

Here’s the free, abridged edition of my weekly “Run Long, Run Healthy” newsletter. It goes to non paying subscribers.

Run long and healthy. Amby


Important result: Stroke risk lowered, not raised, by atrial fibrillation in endurance exercisers 

One of the few bad outcomes associated with long term vigorous exercise is an apparent increase in rates of atrial fibrillation. This is worrisome because AF is linked to a higher risk of stroke. And no one wants that.

However, regular exercisers are weird. Some of the bad stuff that happens to non-exercisers doesn’t happen to those who stay active. One example of this is coronary artery calcium. Large CAC deposits are deadly in men who don’t exercise, especially if they are overweight smokers. But in exercisers, the risk basically disappears. 

Now it seems the same may be true for AF. When Norwegian researchers investigated 500 men who were over age 65 and had been frequent participants in the Birkebeiner 33 mile cross country ski race, they found that the athletes did in fact have a higher incidence of AF. However, “the long-term risk of stroke was substantially reduced [by 40 percent] compared with non-athletes.” So the skiers suffered fewer strokes, which is the feared and dangerous outcome. More at BMJ Open Heart.

Run “quiet” for fewer injuries and no loss of speed

It’s nice, if a bit rare, when a simple piece of running advice proves to have measurable benefits. This study describes one such stride technique.

The researchers wondered what might happen if they asked a group of experienced subjects to “run quieter.” So they designed a study to find out. Here’s the protocol.

Fifteen female runners with a 5K PR under 23 minutes ran on a laboratory treadmill to allow for measurements of their running economy and various forces they generated. Next they did a comfortable 15-minute run while an audio device recorded the sound of their running footfalls on the treadmill. Throughout the effort, they were instructed to “run quieter.” They were also given feedback every 3 minutes regarding the decibels they were producing

For their next week of normal run training at home, the subjects were asked to remember and repeat how they had run quieter in the lab. Then they came back to the lab for retesting of all their initial measurements. 

Result? First, running economy didn’t change. That’s good news. You wouldn’t want to improve one set of measures while lowering another. Also, ground reaction force and loading rate decreased. This might lower injury risks. 

Therefore the researchers concluded: “Simple instructions to ‘run quietly’ can yield immediate and sustained reductions in force profiles, which do not influence running economy.” Runners might benefit from “periodically monitoring foot strike decibel level and focusing on reducing” it. More at Journal of Sport Rehabilitation.

Which does more for your endurance: Altitude training or heat training?

The paper noted here was written about cyclists preparing for the great multi day tours. The findings should mostly apply to distance runners. The basic question: What’s better, altitude training or heat training?

Physiologists have known for a century that altitude training can improve hemoglobin mass and thus boost oxygen efficiency in endurance sports. Usually it requires three weeks residence at 7500 feet or slightly more. There’s reason to believe in the “Live high-Train low” approach (you can maintain speed better at low altitude workouts) but newer research seems to favor “Live high-Train high.”

The concept of heat training for endurance is newer but well established. Heat training improves the “sudomotor response”--you sweat more efficiently and fare better under hot conditions--and can also increase blood plasma and hemoglobin levels if you stay at least 3 weeks in the heat. 

It would be nice to combine both methods to get an additive effect, but “It appears the two may clash if imposed in combination.”  So which environmental training technique wins this battle? The one that mimics where you’ll face your next big race. In distance running, you’re more likely to face heat challenges as in the summer Olympics or World Championships or even unusually warm spring/summer marathons.

Which brings up the question of heat training in winter time for a spring marathon. Is there any point in trying the old multiple “sweat shirts” method? Sure. It might produce “physiological adaptations comparable to natural exposure” while also allowing you to “complete the rest of your weekly training in cooler conditions” to maintain a faster pace. More at Scandinavian J of Medicine & Science in Sports.

16 science-backed benefits of running

I don’t recommend every article about the benefits of running and high-level fitness, because we have heard much of it before. On the other hand, it’s often a good idea to be reminded of that which we already know.

Especially if the reinforcement helps us keep going--the ultimate goal. So here are 16 mostly-scientific benefits of running. I’ve found that their relative importance have changed for me through the years (and decades). Now things like “Running makes you happier” and “Running connects us” rank higher than ever. More at RunStreet.

SHORT STUFF you don’t want to miss

>>> Ladies, be careful. A too-tight heart-rate chest strap could lead to Mondor’s disease. (Here’s the definition of Mondor’s disease.)

>>> The “Mediterranean Diet” is super-healthy but the Green Med approach is even better, especially for belly fat reduction.

That’s it for now. Thanks for reading. See you next week.