Month: August 2022

Enlarge (credit: Fitbit)

Today, Fitbit announced the availability of three new fitness trackers: the Inspire 3, Versa 4, and Sense 2. All successors to previous-generation devices, the three run the gamut from Fitbit’s highest-equipped to most basic fitness wearables.

“Basic” is a relative term among fitness trackers, as they all continuously edge closer to full-blown smartwatch functionality. The Inspire 3, in particular, adds blood oxygen monitoring during sleep and a full-color AMOLED touchscreen to the entry-level tracker, which already can receive phone alerts, like texts, calls, and app notifications. Setting the display to the optional “always on” setting takes battery life estimates down from 10 days to only three, which is much more in line with full-featured smartwatches, though less than Fitbit’s Sense and Versa watches.

By contrast, the Sense 2 and Versa 4 are the two most-capable trackers Fitbit offers. They’re both rated for about six days of use (without the always-on-display enabled) and now feature fast-charging capability that Fitbit claims can give you a day of battery life from only 12 minutes of charging.

Enlarge (credit: Getty | picture alliance)

The incubation period for COVID-19—the time between when SARS-CoV-2 first infects a person and when resulting COVID-19 symptoms first appear—has gradually shortened as the pandemic has stretched on and the virus has mutated. That's according to a new meta-analysis published this week in JAMA Network Open by researchers in Beijing, who harvested data on over 8,000 patients from 142 COVID-19 studies.

When the original version of the novel virus mushroomed out of Wuhan, China, the mean incubation period was 6.65 days, according to pooled data from 119 studies. But then, the incubation period got shorter as the variants evolved. The alpha variant had a mean incubation of 5 days, according to one study; beta, 4.5 days, according to another; delta had a mean of 4.41 days, according to pooled data from six studies; and now with omicron, the incubation period has shrunk to 3.42 days, according to data from five studies.

The current shortened incubation period now puts SARS-CoV-2 more in line with commonplace respiratory viruses, including the four human coronaviruses that circulate seasonally and cause mild infections similar to the common cold. Their incubation period is 3.2 days. Rhinovirus, the most common cause of the common cold, has a mean incubation period of 1.4 days. For influenza it can range from 1.43 to 1.64 days, and parainfluenza has a mean of 2.6 days.