The “normal” number of heartbeats per minute is very much a frequently asked question. People, especially medical people, like well-defined lows and highs. Parameters which can be assigned an ‘L’ or ‘H’ makes life easier.
2009 National Championship Masters (45-49) Road Race
As a modern-day competitive cyclist, I am immersed in a sea of information. In our quest for weekend glory, minutia like speed, wattage outputs, RPMs, torque, elevation gain and of course, heart rates (highs, lows, and averages) get recorded, downloaded, and then studied intensively.
As a heart rhythm specialist, it is a frequent occurrence to see patients referred for low or high heart rates. More often than not, heart doctors are called upon to adjudicate patients who fall outside the “normal” values.
The old school teaching holds that the normal resting heart rate is greater than 55 and less than 100 beats per minute (bpm). Maximal heart rates are estimated by the Read more »
*This blog post was originally published at Dr John M*
A total of 10 adult football helmet models were evaluated using the STAR evaluation system for May 2011 release. All 10 are publicly available at the time of publication. Helmets with lower STAR values provide a reduction in concussion risk compared to helmets with higher STAR values. Based on this, the best overall rating of ‘5 Stars’ has the lowest STAR value. Group rankings are differentiated by statistical significance.
If you’re in the market to buy a loved one a football helmet, or just curious, go and have a look. It doesn’t take long, there are only 10 helmets on the list. Go to the list.
The number of emails that come from fellow cyclists (and endurance athletes) with heart rhythm issues amazes me. I am more convinced than ever that our “hobby” predisposes us to electrical issues like atrial fibrillation (AF)—that the science is right.
Obviously, my pedaling “habit” creates an exposure bias. I hear from many of you because we cyclists understand each other. Like you, I consider not competing a lousy treatment option.
As a bike racer, I know things: that prancing on an elliptical trainer at a health club doesn’t cut it, and, that spin classes may look hard, but do not come close to simulating real competition. I know the extent of the inflammation required to close that gap, to avoid getting dropped when one of the local Cancellara-types have you in the gutter in a cross-wind, or the worst one of all, to turn yourself inside out to stay with a group of climbers over the crest of a seemingly endless hill—”ten more pedal strokes and I’m out”…Then ten turns to 20, then 40, and maybe you hang, and maybe not. The common denominator of all this: suffering.
It’s little wonder that we get AF.
With that as a backdrop, my goal for this post is to provide a modest amount of insight to the most common question asked by athletes with AF.
“Should I have an ablation, or not.”
Though my two episodes of heart chaos amount to only a mild case of AF, I think it’s fair to say that personal experience with a problem helps a doctor better understand your choice. I’ve thought to myself, on more than one occasion, what would I do if the watt-sucking irregularity persisted? Would I have an ablation; would I live with it; would I stop drinking so much coffee? Read more »
*This blog post was originally published at Dr John M*
For this week’s CBS Doc Dot Com segment, I thought I’d cover something completely non-controversial: what can weekend warriors learn from elite athletes? But I’m starting to believe that in this era of evidence-based medicine, nothing may be truly knowable. I went to the studios of the world famous Ballet Hispanico in New York City and spoke to athletic trainer Megan Richardson. She took me through the motions, emphasizing the importance of warming up and stretching in preventing injury. It sounded good and it felt good. But proving in the medical literature that it’s effective is another thing. An online search quickly produced multiple conflicting reports and advice: stretching definitely works, stretching definitely doesn’t work; stretching only works if you do it my way. Click here for a sampling:
My friend and CBS colleague, Richard Schlesinger, offered his solution. ”I get around it by neither stretching nor exercising.” Had I listened to Richard, my blog post would have ended right here. But I figured I needed at least one more paragraph so I contacted a true expert on the subject, Ian Shrier MD, PhD, a specialist in sports medicine and Associate Professor at McGill University. He has a PhD in physiology and is Past-President, Canadian Academy of Sport Medicine. He’s not a huge fan of stretching right before exercise.
“First, the stretching, whether with or without warmup, does not improve performance. It makes you run slower, jump not as high, and makes you weaker.” And “stretching definitely can hurt people if you overstretch; people do it all the time if they force the stretch.”
He added, “I don’t think it hurts you in general if you do it properly but it doesn’t prevent injury.” He’s more supportive of stretching at other times, including after exercise, saying, “Regular stretching at other times is beneficial. It makes you stronger, jump higher, etc, and there are three studies suggesting it reduces injuries as well, although the results were only significant in one.” He adds that “stretching is analgesic; it allows you to put your muscle through a wider range of motion without feeling tension. And that may be why ballerinas say that stretching helps them.” Dr. Shrier spells out his take on the subject in detail in a chapter called
“Does stretching help prevent injuries?”
For me, Dr. Shrier’s most interesting advice, especially for weekend warriors, was about the importance of warming up. He explained that muscles need energy to function properly. Energy is mainly produced inside of cells in structures called mitochondria. When you are resting, your mitochondria power down. During exercise, it takes awhile for the cell to rev up the enzymes needed for breaking down fat and carbohydrates for fuel and for using oxygen to make energy from that fuel. If you start running at full speed without warming up, your body will produce lactic acid. Lactic acid can impair muscle function for awhile, preventing you from sprinting efficiently at the end of the race.
So Dr. Shrier suggests gradually warming up. He estimated it takes about 3 to 5 minutes to efficiently go from one level of exercise to the next – for example, going from rest to a ten minute mile or going from a ten minute mile to a seven minute mile. If you go for a jog, “you walk, then jog slowly, and then pick it up. Elite marathoners might go for a fifteen to twenty minute jog before they run a marathon. That allows them to run faster at the beginning of the race. They run the second half of the marathon faster than the first.”
In summary – and I suspect that I am the first person today to tell you this – don’t outpace your mitochondria.
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