Why workouts may not always work out
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A protein produced by the liver may limit the benefits of regular exercise.
Medical guidelines recommend at least 2.5 hours of moderate exercise, such as cycling, each week to stay healthy. However, studies show that not everyone’s aerobic fitness improves from toiling on the treadmill. A team led by researchers from Kanazawa University have found that selenoprotein P (SeP), a protein found in the liver, could be responsible.
The researchers fattened up mice that lacked either SeP or the muscle-based SeP receptor (LRP1) and wild-type mice, and put them on a treadmill for 30 minutes per day. After four weeks the SeP- and LRP1-deficient mice could run further and for longer than the control group.
The team also measured SeP in the blood of 31 healthy, post-menopausal women before an eight-week exercise program. Women with lower levels of SeP made greater gains in their aerobic capacity.
These results suggest that blocking SeP from reaching the muscles may improve the effectiveness of exercise in treating obesity and diabetes.
- Nature Medicine 23,508–519 (2017). doi: 10.1038/nm.4295