The Rundown

A.M. Rx. Researchers at the University of California, Berkeley have a prescription for waking up in the morning without feeling groggy: Sleep, exercise and breakfast.

Over two-weeks, 833 people were given a variety of meals at breakfast, wore watches to record their physical activity and sleep quantity, quality, timing and regularity, kept diaries of food intake and recorded their levels of alertness from waking up and throughout the day.

The study found that the keys to morning alertness are:

1. Substantial exercise the previous day, the idea being that exercise improves mood and mood was correlated to alertness levels.

2. Sleeping longer (between seven and nine hours) and later in the morning. Waking up later means you are rising at a higher point on the upswing of your 24-hour circadian rhythm.

3. Eating a breakfast that is high in complex carbohydrates, with limited sugar.

VO2max in Wearables. A measurement of VO2max (the capacity of the body to carry out aerobic work) is considered the gold standard of fitness tests.

To test their VO2max, professional athletes measure their oxygen consumption while they exercise to exhaustion. In the lab, measuring VO2max involves heart rate responses to exercise tests that require equipment like a treadmill or exercise bike.

But what if you could accurately predict VO2max using data from a wearable device—no exercise test needed? In a new study, scientists from the University of Cambridge say it’s possible using their model.

The researchers took activity data from more than 11,000 participants in the Fenland Study (a long running public health study in eastern England). The study volunteers wore wearable devices for six consecutive days. This baseline data was compared with follow-up data from a subset of 2,675 of the original participants taken seven years later.

An AI model known as a deep neural network processed and extracted meaningful information from the raw sensor data and made predictions of VO2max from it. The model was validated against a third group of participants who performed a standard lab-based exercise test.

The AI model had a high degree of accuracy compared to lab-based tests and strong agreement with the measured VO2max scores at both baseline (82% agreement) and follow-up testing (72% agreement).

While a few smartwatches and fitness monitors currently on the market claim to give an estimate of VO2max, the algorithms fueling these estimates aren’t published and may change at any time. So it’s unclear if the predications are accurate or whether an exercise plan is having any effect on your VO2max over time.

The new research suggests that accuracy without an exercise test is possible but if VO2max measurements via your smart watch are to be trusted, transparency needs to be improved. According to senior author Cecilia Mascolo, the wearables we use everyday can be just as powerful as an expensive lab test to get a real measurement of fitness but only “if they have the right algorithm behind them.”

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U.S. Soccer. The U.S. may be out of the World Cup but HBO Max doesn’t want you to miss any of the action. Starting January 17, you can stream tournaments and matches from the U.S. Men's and Women’s National teams.

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