Walking quickly is associated with a decreased risk of cardiac rhythm problems.

According to study published online in the journal cardiac, walking at a brisk pace and for a longer period of time may reduce the incidence of cardiac rhythm disorders such atrial fibrillation, tachycardia (rapid heartbeat), and bradycardia (extremely slow heartbeat).
The results were true regardless of established cardiovascular risk factors, but they were more pronounced in women, those under 60, people without obesity, and people with long-term medical issues.

The authors point out that heart rhythm irregularities, or arrhythmias, are frequent; atrial fibrillation alone has doubled in prevalence during the last three decades, reaching close to 60 million instances globally in 2019.
They say that identifying modifiable risk factors is crucial to preventing the negative impact on health because these abnormalities are linked to increased risks of cardiovascular disease, sudden cardiac death, and disability.

Few research have examined walking pace's possible effect on irregular heart rhythms, despite the fact that it is linked to decreased risks of cardiovascular disease and death.

Therefore, in addition to investigating the possible roles of metabolic variables and inflammation, the researchers also examined the effects of varying walking speeds and risk factors, including age, sex, obesity, smoking, alcohol use, and pre-existing long-term diseases.
They used information on walking speeds from questionnaire replies for 420,925 UK Biobank individuals. For 81,956 of them, the quantity of time spent walking at various paces was available based on activity tracker readings.

Walking less than three miles per hour was considered slow, three to four miles per hour was considered steady or ordinary, and more than four miles per hour was considered brisk.

The participants' average age was 55; the majority (97%) were White, and over half (55%) were female.

Overall, 221,664 participants (53%) reported walking at an average rate, 171,384 participants (41%) reported walking at a brisk pace, and 27,877 people (just over 6.5%) reported walking slowly.
36,574 (9%) participants experienced heart rhythm abnormalities over the course of an average tracking period of 13 years: 21,68 ventricular arrhythmias (abnormal rhythms originating in the lower chambers of the heart); 19,093 other cardiac arrhythmias; 5678 an abnormally slow heart rate; and 23,526 atrial fibrillation.

Men were more likely than women to report walking more quickly, and they also tended to lead healthier lifestyles and reside in less impoverished areas. In addition, they weighed less, had superior grip strength, smaller waists, lower levels of metabolic risk factors like fasting glucose and blood lipids, less inflammation, and fewer chronic illnesses.
An average or brisk walking rate was linked to considerably decreased (35% and 43%, respectively) odds of all cardiac rhythm abnormalities when compared to a slow walking pace, even after controlling for potentially significant background demographic and lifestyle characteristics.

Additionally, compared to those who reported walking slowly, these walking speeds were linked to lower chances of atrial fibrillation (38% and 46%, respectively) and other cardiac arrhythmias (21% and 39%, respectively).

Some 4117 of the 81,956 participants with activity tracker data developed arrhythmias. Those who spent more time walking at a brisk pace were generally younger, more likely to be White and male, and live in less deprived areas. They generally had healthier lifestyles, and were healthier, overall.

While the amount of time spent walking at a slow pace wasn't associated with the risk of developing heart rhythm abnormalities, more time spent walking at an average or brisk pace was associated with a 27% lower risk.

Overall, around 36% of the association between walking pace and all heart rhythm abnormalities was influenced by metabolic and inflammatory factors.

The observed associations were independent of known cardiovascular risk factors, but were strongest in women, the under 60s, those who weren't obese, those who had high blood pressure, and those with 2 or more long term conditions.

This is an observational study, and as such, no firm conclusions can be drawn about cause and effect. And the researchers acknowledge that part of the study relied on self report while the study participants didn't reflect a broad spectrum of ages and ethnic backgrounds.

But they write: "This study is the first to explore the pathways underpinning the association between walking pace and arrhythmias, and to provide evidence that metabolic and inflammatory factors may have a role: walking faster decreased the risk of obesity and inflammation, which, in turn, reduced the risk of arrhythmia."

And they explain: "This finding is biologically plausible because cumulative epidemiological studies have shown that walking pace is inversely associated with metabolic factors, such as obesity, HbA1c [fasting glucose], diabetes, and [high blood pressure] which, in turn, are associated with the risk of arrhythmias."