Caffeine and Exercise Performance, HITT and Type 2 Diabetes, Physical Activity and Sedentary Time and More from the Journal of Medicine & Science in Sports & Science®


Blood Flow Restriction Increases Muscle Protein Synthesis When Combined with Exercise

Performing resistance exercise with heavy weights is effective for increasing skeletal muscle mass. However, when individuals (such as injured athletes or hospitalized patients) are not capable of exercising with heavy weights, they risk losing substantial amounts of muscle. Previous studies in humans and animals suggest that performing such exercise while restricting blood flow at the same time might stimulate skeletal muscle maintenance and growth, without the need to use heavy weights. Blood flow restriction is a procedure in which a pressure cuff is placed around an arm or leg to reduce blood flowing in and out of a muscle for a short period of time ̶ for a maximum of five minutes. Researchers in this study assessed whether performing blood flow restriction with or without low-weight resistance exercise stimulated muscle protein synthesis in a group of 20 healthy young men. They observed that blood flow restriction, combined with low-weight exercise, increased skeletal muscle protein synthesis when compared to the same exercise performed without blood flow restriction. Blood flow restriction performed without exercise showed no effect. These findings suggest that performing blood flow restriction with low-weight exercise may be an effective strategy to stimulate muscle growth, when heavy weight resistance exercise is not possible. View the abstract or contact the investigator for more information.

Battle of the Sexes: Who Benefits More from Caffeine?

Caffeine is the wonder-drug that helps improve endurance exercise performance in men. However, less than 20 percent of all studies on such effects have included a woman. And, those studies including women have had mixed results. This is likely because those studies didn’t consider the influence of oral contraceptives on caffeine metabolism. In this new study, the scientists studied both women (11) and men (16) cyclists and triathletes. The women consumed amounts of caffeine equal to about one-two cups of espresso, while the men had about two-three cups of espresso (adjusted according to body weight). Subjects were given the caffeine before performing the same endurance cycling protocol. The investigators found that caffeine improved cycling performance by 4.3 percent in women and 4.6 percent in men. This equal benefit happened even though the women, who all were on an oral contraceptive pill, had higher levels of caffeine in their bloodstreams. These results suggest that caffeine consumed about an hour before exercise can equally improve exercise performance in both men and women. View the abstract or contact the investigator for more information.

High-Intensity Exercise May Restore Heart Function in People with Type 2 Diabetes

Loss of heart function is a major cause of disability and ill-health in people with diabetes. In this investigation, the researchers studied adaptations to three months of high-intensity interval training (HIIT) in a group of 11 adults with type 2 diabetes; five additional volunteers with type 2 diabetes were controls and did not train. The study results showed that the training improved heart function in adults with type 2 diabetes, without any change in medications or diet. The improvement of the diabetic heart was particularly evident during exercise. Current exercise recommendations suggest that people with diabetes may be non-compliant with vigorous exercise. However, HIIT, which includes intervals of near-maximal effort, was safe, acceptable and well attended (more than 80 percent adherence) by middle-aged adults with type 2 diabetes. This suggests that exercise at sufficiently high intensity may provide an inexpensive, practical way to reverse, or reduce the loss in heart function caused by type 2 diabetes. View the abstract or contact the investigator for more information.

Too Much Sitting Can Lead to Worsened Health ̶ Is Exercise Enough?

Modern society has changed in a way that many adults spend most of their day sitting ̶ which can be hazardous to health. The health benefits of exercise are undisputed and widely recommended, whereas the importance of reducing sitting time receives much less attention. Researchers at the Institute of Ageing and Chronic Disease, University of Liverpool in the UK, aimed to understand the importance of different levels of physical activity and sitting time. Ninety-eight middle-aged adults were asked to wear activity monitors during their normal daily routine and were invited to undertake a series of health measures. The results showed that greater sitting time was associated with worsened health including bigger waist circumference, higher blood pressure and cholesterol and greater amounts of liver fat, ultimately imposing an increased disease risk. On the other hand, exercise duration did not have a clear effect. The people in this study were generally active, which highlights the importance of limiting sitting time and demonstrates how an active lifestyle does not eliminate the harmful effects. Recommendations for sedentary time are needed in addition to, and not a substitute for, a physically active lifestyle. View the abstract or contact the investigator for more information.


Comment/Share

Chat now!
1.73721