Unit 1 Relationships 单元限时小卷-【高中必刷题】2024-2025学年新教材高中英语选择性必修第一册同步课件（北师大版2019）

05 单元限时小卷 1 [浙江浙南名校联盟2024高二期中] It’s well known that weightlifting can strengthen our biceps （二头肌）. Now, there’s increasing evidence that strengthening the muscles we use to breathe is beneficial too. New research shows that daily muscle training for breathing muscles helps promote heart health and reduces high blood pressure. “The muscles we use to breathe tend to weaken as we get older,” explains researcher Daniel, a physiologist at the University of Colorado Boulder. To test what happens when these muscles are given a good workout, he and his colleagues recruited （招收） healthy volunteers aged 18 to 82 to try a daily five-minute technique using a resistance-breathing training device. When people breathe into it, the device provides resistance, making it harder to breathe in. “We found that doing 30 breaths per day for six weeks lowers systolic blood pressure by about 9 mmHg,” Daniel says. According to Joyner, a physician at the Mayo Clinic who studies how the nervous system regulates blood pressure, that is the type of reduction with a blood pressure drug. 刷阅读理解 2 So, how exactly does breath training lower blood pressure? Daniel points to the role of endothelial cells （内皮细胞）, which promote the production of NO. NO helps widen our blood vessels （血管） and promote good blood flow. “What we found was that six weeks of the training will increase endothelial function by about 45%,” Daniel explains. The new study builds on a previous study and adds to the evidence that the training is beneficial for adults of all ages. Before the results came in, Daniel had suspected that young, healthy adults might not benefit as much. “But we saw strong effects,” he says, pointing to a significant decline in blood pressure for participants of all ages. He says the finding suggests the training could help healthy young people prevent heart disease and the rise in blood pressure that tends to occur with ageing. The technique is not intended to replace exercise, he cauti