March

fitness

Navy physical fitness assessments to resume in March, CNP says

Sailors can expect physical fitness assessments to pick up again in March 2021, according to Chief of Naval Personnel Vice Adm. John Nowell Jr.

In response to the COVID-19 pandemic, the Navy initially announced in March 2020 that it was postponing its spring cycle of the Navy’s PFA. Ultimately, the pandemic prompted the Navy to eliminate all physical fitness tests for the rest of 2020.

“We’re looking at for the PFA, based upon feedback and risk-to-mission, risk-to-force, right?” Nowell said during a Facebook live “town hall” event Tuesday. “Risk-to-mission — we’ve gone a year without it, so we know that we really do need to go ahead and get that going again.”

Sailors were gearing up for PFAs to kick off again in the new year after Nowell said in September the fitness exams would resume in January 2021. But given the rising number of COVID-19 cases, Nowell said Tuesday, the Navy will not proceed with two cycles of PFAs starting in January and instead, will opt for one cycle starting in March.

EO3 (SCW) Simon Charumonta, assigned to Naval Mobile Construction Battalion 3, finishes strong during the push-up portion of the physical fitness assessment at Naval Base Ventura County in July 2017. (MC1 Chris Fahey/Navy)

“January is still right in the middle of flu season and so we are close to the formal approval to go ahead and get the word out that we will do one cycle next year,” Nowell said. “It will start toward the middle of March — so after flu season, when it’s warm enough — as we look at doing it for about six months, through September, so you can get outside and do it, mitigate that risk.”

Sailors can also brace themselves for the introduction of several new elements to physical fitness tests come 2021, such as the flexibility to use the rowing machine as an additional cardio option. Likewise, the Navy has chosen planks in lieu of curl ups — a change that was in place prior to the pandemic.

“We’re going to do planks, not curl ups, so you won’t be in someone’s face … that then kind of keeps you pretty safe,” Nowell said.

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health

How Covid-19 Death-Rate Predictions Have Changed Since March

In March, estimates of how many Americans would die from Covid-19 in the coming months ranged from 81,000 to 2.2 million.

That disparity—which arguably produced as much confusion as insight—prompted one independent data scientist to build his own model in hopes of arriving at a better forecast. (He did.)

Now, as many as 50 different research groups make predictions, but one of the most accurate assembles all of the individual models, calculates the median value and looks no more than four weeks into the future.

The ensemble forecast was founded by the Reich Lab at the University of Massachusetts, Amherst, in collaboration with the Centers for Disease Control and Prevention and is based in part on models previously developed to forecast influenza and other infectious diseases.

In the next four weeks, it predicts the total number of deaths attributed to the new coronavirus will surpass 240,000—adding roughly 17,000 deaths to the current tally.

Such projections help policy makers and health-care officials decide how to manage resources and implement or relax interventions intended to curb the spread of the disease.

“It gives you guideposts,” said Jeffrey Shaman, an infectious-disease modeler at the Mailman School of Public Health at Columbia University. “Are you going in a bad or good direction? Is it under control?”

But even now, the projections of individual models sometimes differ substantially, according to Michael Johansson, co-leader of the CDC’s Covid-19 modeling team. In June, one model predicted that by July, the death toll would top 263,000. Another anticipated that it would be less than 120,000.

By focusing on the median, the ensemble forecast has consistently provided reliable four-week projections. In this case, its projection was 130,558, and the actual figure was 130,089.

“That’s been one of the big advantages,” Dr. Johansson said. “By leveraging all the information from all the model approaches, we get forecasts that are demonstrably robust.”

The Covid-19 Forecast Hub is the central repository for individual forecasts. Those included in the ensemble—currently more than 40—are probabilistic forecasts that look four weeks into the future; provide a point estimate of the expected number of deaths in the period; and include the range within which the actual number will likely fall with prediction intervals of 95% and 50%.

The ranges for each forecast are divided into 23 quantiles. The Hub calculates the median for each quantile, and the ensemble forecast is the median of those values.

“Because of previous work, we know you don’t want to exclude models unless there is a clear reason to do so,” Dr. Johansson said. “They capture different things.”

By confining the forecasts to the short term, changes in policy or public behavior are also less likely to upset the projections.

In contrast, the earlier models tried to predict the number of deaths that would occur months later.

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“Forecasts beyond a relatively short prediction window are not going to be very robust,” Dr. Johansson said. “You

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