Smart-Bracelet-Guided Low-Intensity Exercise Promotes Gastric Emptying after Fasting: A Randomized Controlled Clinical Trial
This randomized controlled trial demonstrates that smart-bracelet-monitored low-intensity walking effectively accelerates gastric emptying and shortens gastric emptying time in fasting individuals consuming a glucose beverage, without increasing the risk of high-risk stomach, thereby supporting its use as a safe adjunct to optimize preoperative fasting management under Enhanced Recovery After Surgery (ERAS) protocols.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Before a major surgery, patients are usually told to stop eating and drinking for many hours. This rule exists to keep the stomach empty, reducing the chance that food or liquid could be accidentally inhaled into the lungs while the patient is asleep. However, modern medical guidelines have begun to suggest that drinking a clear, sugary liquid a few hours before the operation might actually be helpful. It can reduce the body's stress response and make patients feel less thirsty and hungry. The problem is that for some people, the stomach does not empty this liquid as quickly as doctors hope, leaving them with a "full stomach" right up until the moment of anesthesia. This creates a dilemma: doctors want the benefits of the drink but fear the risk of a full stomach. Researchers have long known that gentle movement, like walking, can help the digestive system work better, but they did not know if a short walk could safely speed up the emptying of a sugary drink in a pre-surgery setting without causing harm.
To answer this question, a team of researchers at Sichuan Provincial Orthopedic Hospital in China conducted a careful study involving healthy volunteers. They wanted to see if a specific type of low-intensity walking, monitored by a common fitness tracker, could help the stomach empty a sugary drink faster than simply resting. The study began with 81 volunteers who had followed strict fasting rules: no solid food for at least eight hours and no liquids for at least two hours. This ensured their stomachs were empty before the experiment started. Once the fasting period was confirmed using a special ultrasound scan that looks at the size of the stomach's outlet, every participant drank 400 milliliters of a 10 percent glucose solution, which is a clear, sweet liquid similar to what is often recommended before surgery.
The volunteers were then split into two groups. One group, the control group, simply sat or lay down and rested quietly after drinking the liquid. The other group, the intervention group, put on a smart wristband and began a structured walking routine. This was not a vigorous workout; the participants walked on flat ground at a slow, comfortable pace, roughly between 3 and 4.5 kilometers per hour. The smart wristband monitored their heart rate to ensure they stayed in a low-intensity zone, defined as half of their maximum heart rate. They walked for 15 minutes, rested, and then repeated this cycle four times over the next few hours. Throughout the entire process, doctors used ultrasound machines to take pictures of the bottom part of the stomach, known as the antrum, at regular intervals. By measuring the size of this area, they could calculate exactly how much liquid remained and how fast it was leaving the stomach.
The results showed a clear difference between the two groups. The people who walked had a smaller stomach area at specific times after drinking the liquid compared to those who rested. This meant their stomachs were emptier. More importantly, the group that walked finished emptying their stomachs significantly faster. On average, the walkers took about 114 minutes to clear the liquid from their stomachs, while the resting group took nearly 130 minutes. This is a difference of about 16 minutes. The data indicated that the walking group emptied the liquid more efficiently, particularly at the one-hour and two-hour marks after drinking. Crucially, the researchers found that this faster emptying did not create any new dangers. They checked for signs of a "high-risk stomach," a condition where too much liquid remains, which could be dangerous during anesthesia. They found no increase in this risk for the walking group; in fact, the number of people with a high-risk stomach was similar in both groups, and all cases were mild.
The study suggests that a simple, monitored walk can be a safe and effective way to help the stomach process a pre-surgery drink. The researchers believe this happens because gentle movement stimulates the nerves that control the stomach and improves blood flow to the digestive organs, encouraging the stomach to push the liquid forward. The use of a consumer-grade smart bracelet made it possible to keep the exercise intensity low and consistent, ensuring that the activity remained safe and did not divert blood flow away from the stomach. While this study was conducted on healthy volunteers and not on patients with complex medical conditions, the findings offer a promising, non-drug method to improve pre-surgery care. It provides a practical way to bridge the gap between the old habit of long, strict fasting and the newer, more comfortable guidelines that allow for preoperative drinks, potentially making the time before surgery more comfortable and safer for patients.
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