Weight-Training for Life

In this week's Rundown, Amazon helps the Sandman, how insufficient sleep damages your immune system, and the amount of time you need to spend weight-training to lower your risk of death.

The Rundown

Enter Sandman. Amazon has entered the sleep-tracking market with the announcement of the Halo Rise (read the press release). The device sits on your bedside table and has no wearable component. Instead, it monitors your respiration and movement with an integrated radar sensor.

The radar sensor emits ultra-low-power radio signals that are reflected off the user and received by several antennas on the device. The Rise uses machine learning based algorithms to analyze the radar data and determine how much time you spend in REM, light and deep sleep. Additional sensors monitor temperature, humidity and light levels.

In the morning, you can see a sleep summary on the Halo app, which includes a graph showing how much time you spent in each sleep phase, an overall score for the night and recommendations for changes to improve your sleep environment.

Immunity Zzzz’s. Speaking of sleep, a new study published in the Journal of Experimental Medicine, says that getting an insufficient amount can adversely impact your immunity, making you more vulnerable to infections and inflammatory disease. The cause? Damage to your hematopoietic stem cells.

Hematopoiesis is the process by which our bodies regenerate new blood cells, including immune cells or monocytes. For the study, researchers wanted to discover how sleep influences this process, specifically monocyte production, so fourteen healthy adults were recruited for a sleep experiment.

First, the group was asked to get a minimum of 7.5 hours of sleep per night for six weeks. They had a break and were then asked to reduce their sleep by around 90 minutes for an additional six weeks. Blood samples were taken several times throughout.

The researchers found six weeks of sleep disruption caused significant changes in the participants’ hematopoietic stem and progenitor cells (HSPCs), the precursor stem cells that eventually turn into monocytes. Also, the DNA structure of these HSPCs were changed in a way that promoted inflammatory states and there were more of them in the blood.

The findings from the study were replicated in studies using mice but the team made another discovery in the mice studies. They found signals suggesting that the sleep deprivation to stem cells may not return to normal with better sleep practices.

Lead investigator, Cameron McAlpine, explains: “Our findings suggest that sleep recovery is not able to fully reverse the effects of poor-quality sleep. We can detect a molecular imprint of insufficient sleep in immune stem cells, even after weeks of recovery sleep.” This imprint, he says, can cause cells “to respond in inappropriate ways leading to inflammation and disease.”

Weight-Training for Life. Exercise science research has long touted benefits of weight-training that go beyond looking cut and lean. The latest study to contribute to this body of knowledge explores the links between muscle-strengthening activities and risk of death. It found that as little as 30-60 minutes of weight-training a week could have an impact on our longevity.

A team of Japanese scientists conducted a systematic review of 16 studies on the exercise activities of adults with no serious health problems. The review covered the weight-training habits of hundreds of thousands of men and women aged 18-97.

Previous studies have found that weight-training generally carries a lower risk of death. What these researchers wanted to know is the ideal amount of training. Their review revealed that a maximum effect was 30-60 minutes per week, which lowered the risk of death from any cause by 10 to 20%. They found no conclusive evidence that doing more than an hour of weight-training had any extra benefit.

Combining weight-training with aerobic exercise had an even greater impact, as it was associated with a 40% decrease in risk from any cause, a 46% decrease in risk from cardiovascular disease and a 28% decrease in risk of death from cancer.

Some limitations: The reviewed studies were based on subjective assessments of weight-training rather than observation in a clinical setting and most studies were performed in the US.

Replay

This week’s vintage moment in sports culture is brought to you by the Fog Bowl. Philadelphia Eagles at Chicago Bears, December 31, 1988. Photo: Heinz Kluetmeier.