A study by researchers from Virginia Tech and the UK suggests that high-fat, low-carb ketogenic diets may improve health in some cases, especially when combined with exercise. The researchers found that when mice with high blood sugar (hyperglycemia) were put on a strict keto diet, their blood sugar levels returned to normal and their exercise activity increased. Their muscles became more fatigue-resistant and oxygen-rich after eight weeks on the diet. The findings suggest that the diet can reverse both high and exercise inefficiencies, but cautioned that it hasn't been tested in mice so far and the improvements were not seen in animals with normal blood sugar. The study suggests that different approaches to diet and exercise might be needed to maintain health and aerobic performance.