Can Too Much Sitting Increase the Risk of Depression?
The average adult sits up to 10 hours a day. Sedentary behaviors are known to increase the risk of cardiovascular disease, diabetes and premature death. While these risks may be partly offset by high levels of exercise, most people do not achieve the levels needed. Recent evidence suggests that high volumes of sitting can also be associated with poorer mental health. In a series of studies linking sitting survey data with clinician diagnoses of depression and anxiety, investigators tested the possibility that certain types of sedentary behavior might be worse for mental health than others. They found that mentally-passive sedentary behaviors like TV-viewing increase the risk of depression, whereas those involving mental activity (i.e., reading, office work and problem solving) reduce such risk. Thus, in the context of psychological wellbeing, the way we use our brain while sitting appears to be important. Structured exercise should always be encouraged for better physical and mental health. In addition, encouraging more mentally active sedentary behaviors may be an effective approach to prevent depression, especially in those for whom physical activity or structured exercise can be challenging. View the abstract.
Sport-Safety Meets Science: How Data-Informed Coaching Practices Can Help Make Football Safe
Sport participation is a key contributor to the physical and mental well-being of youth. However, increasing rates of concussion, along with concerns about the effect of repetitive head impacts on brain health, have caused reasonable concern over the safety of contact sports like football. Investigators demonstrate that pre-season evaluations targeting specific skills can be used to develop behavioral interventions that improve athletes’ abilities to engage in safer contact. Equipped with helmet-sensors, 70 high school football players showed a 30% reduction in head impacts after taking part in a one-month intervention that implemented safer blocking and tackling techniques. These results suggest that data-informed interventions can be used to assess, modify and improve contact skills in high school football players. Coaching practices employing such interventions will help ensure that athletes enjoy the benefits of team-based contact sports while reducing trauma and health care expenses resulting from head injuries. View the abstract.
Can Your Wearable Device Really Tell How Fit You Are?
Fitbits and other wearable fitness monitors often provide values for VO2max (“cardio fitness score” in the Fitbit app), a measure of how well the body transports and uses oxygen to produce energy needed for physical activity. Strong relationships exist between VO2max and the risks of cardiovascular disease, some cancers and even death. Thus, the American Heart Association has recommended that it be regularly assessed as a clinical vital sign and used for personalized exercise prescription. Given that its measurement is time consuming and requires costly specialized equipment, accurately estimating VO2max at home with a relatively inexpensive wearable would allow more people to determine their cardiorespiratory fitness. Investigators in this study had 60 adults, aged 18 to 45 years, wear a Fitbit Charge 2 for one week while completing at least three 15-minute runs on flat terrain and compared the resulting VO2max estimate to the value obtained from a lab VO2max test on a treadmill. The Fitbit predicted VO2max with less than 10% error, suggesting that wearable devices can provide relatively accurate estimates of cardiorespiratory fitness in people who can run longer than 10 minutes on flat terrain. Read the article.
Increasing already? Finding the Best Way to Monitor Load Progressions in Strength Training for Older Adults
Although researchers agree that occasional increases in workload are necessary for continued strength gain in older adults, the most effective method of monitoring and progressing load has not been identified. Progress too slowly and risk boredom and mediocre levels of improvement. Progress too quickly and the risks of muscle soreness and program dropout skyrocket. Researchers at the University of Miami approached this dilemma by recruiting 82 older adults with limited experience to complete 12 weeks of supervised weight training. Participants were randomly assigned to exercise programs that differed by how researchers increased loads during training. While all groups saw similar improvements in muscular strength, subjects who increased their workloads based on Ratings of Perceived Exertion (RPE) found exercise significantly more tolerable and enjoyable than participants whose progression was determined specifically by the amount of weight they were able to lift. The finding that muscular strength can be improved in older adults with a lower perception of effort than shown in the past is important since perceived tolerance and enjoyment are two key factors predicting continued exercise participation. View the abstract.
Successful Method of Monitoring Important Skeletal Muscle Ion Pump Identified
The enzyme Na+/K+ ATPase (NKA, also known as the sodium potassium pump) is critical to the function and maintenance of the body’s cells. Investigators have long sought to clarify the role of NKA in the regulation of skeletal muscle in both healthy and diseased states, yet progress has been limited due to background contamination from other ATPases present in skeletal muscle. This includes a prevalent enzyme directly involved in muscle contraction. To address this problem, investigators attempted to test the function of NKA in the muscle cells of mice and humans in the presence of a specific myosin ATPase inhibitor. Adding the inhibitor resulted in a threefold decrease in the background activity of myosin ATPase activity and a dramatic reduction in the amount of muscle tissue needed to determine NKA activity. Furthermore, adding specific amounts of sodium enabled investigators to accurately determine the amount of NKA activity in the muscle. The technique employed in this study should allow for broader examination of NKA activity in conditions like aging, physical inactivity and muscle-wasting diseases. View the abstract.