Background: Regular physical activity (PA) and low sedentariness have significant long-term health benefits. Achieving and measuring adequate levels of PA are difficult in office environments. This study’s primary aim was to evaluate PA levels and sedentariness within work and home settings. The accuracy of self-reported physical activity and accelerometer use acceptability were also determined. Methods: 121 university staff, students and fellows (faculty) gave informed consent. Pre-study questionnaires on PA, sedentary time, mood and sleep were completed. Using a FitBit One accelerometer PA was monitored for 7 days. Steps were counted. PA intensity was categorized as light or moderate-to-vigorous (MVPA). Group differences were compared with Spearman’s and Pearson’s correlation tests. Results: Average pre-study activity estimation was 1.18 hrs/day (SD: 0.622) (95%CI ± 0.049). Subsequently, each participant averaged 1.49 hrs/day (SD: 0.98) walking; (70.9 mins/day (SD: 45.0) moderate activity (3–5 Metabolic Equivalents (METs); 20.5mins/day (SD: 17.2) vigorous activity (>5METs). Average daily sedentary time was 654.6 min (±152.3), with average time at work standing or in very light activity as 6.47 hrs (SD: 4.3 hrs) (<1.5METs). Self-estimated pre-study walking activity and objectively measured PA (R2 = –0.172) were not correlated. Participant acceptability rating for device use was 87%. Conclusion: All participants achieved near recommended PA levels. Work and home environments contributed reciprocally to daily totals. Significant differences between self-reported and measured PA levels indicates that both should be recorded.

In part 42 of our A–Z series of nutritional supplements, having covered vitamins in parts 39–41, we finish off reviewing V by looking at valine, an essential amino acid (EAA) classified as a branched chain amino acid (BCAA), and vanadium, a trace element marketed as an aid to muscle growth in weight training. We then turn our attention to W, with the first W to be reviewed being ‘water (oxygenated)’. Oxygenated water products are marketed to athletes with a claim that, dependent on the product, they contain 3–30 times the oxygen content of normal tap water, and thereby could potentially be of benefit to health and performance. It is worth noting that these oxygenated water products are not to be confused with doubly labelled water (DLW). In DLW, the water is generally labelled with the heavy, non-radioactive isotope forms of the elements deuterium (symbol D or 2H, also known as heavy hydrogen) and the isotope of oxygen, oxygen-18 (18O, as opposed to the normal oxygen-16, 16O), combining to become deuterium oxide-18 (D218O). DLW is commonly used to measure metabolic rate, particularly ‘in the field’ and for longer periods of measurement, where more accurate direct or indirect calorimetric measurements would be rather difficult. ### Valine #### AB Hodgson Valine is an EAA which, together with leucine and isoleucine, is classified as a BCAA (reviewed previously in part 4 of this series).1 The investigation of valine, in isolation from other BCAA, has received little attention. Valine is …

One of the most concerned problems in neuroscience is how neurons communicate and convey information through spikes. There is abundant evidence in sensory systems to support the use of precise timing of spikes to encode information. However, it remains unknown whether precise temporal patterns could be generated to drive output in the primary motor cortex (M1), a brain area containing ample recurrent connections that may destroy temporal fidelity. Here, we used a novel brain-machine interface that mapped the temporal order and precision of motor cortex activity to the auditory cursor and reward to guide the generation of precise temporal patterns in M1. During the course of learning, rats performed the “temporal neuroprosthetics” in a goal-directed manner with increasing proficiency. Precisely timed spiking activity in M1 was volitionally and robustly produced under this “temporal neuroprosthetics”, demonstrating the feasibility of M1 implementing temporal codes. Population analysis showed that the local network was coordinated in a fine time scale as the overall excitation heightened. Furthermore, we found that the directed connection between neurons assigned to directly control the output (“direct neurons”) was strengthened throughout learning, as well as connections in the subnetwork that contains direct neurons. Network models revealed that excitatory gain and strengthening of subnetwork connectivity transitioned neural states to a more synchronous regime, which improved the sensitivity for coincidence detection and, thus, the precision of spike patterns. Therefore, our results suggested the recurrent connections facilitate the implementation of precise temporal patterns instead of impairing them, which provided new perspectives on the fine-timescale activity and dynamics of M1.

Introduction There is anecdotal evidence that obese individuals suffer from poor wound healing and frequent minor illnesses such as upper respiratory tract infections (URTI) cf. lean individuals. The altered metabolic, psychological and endocrine status of obesity may lead to immunodepression. Our group has investigated URTI in fatigued athletes and military personnel (Castell, 2003); one study focused on the obesity hormone, leptin which regulates energy balance, and its role in immune function. Decreased circulating leptin can lead to hyperphagia in some genetically obese individuals (O’Rahilly, 2002). However, human obesity is usually characterized by excessive leptin, rather than deficiency. The leptin functional receptor is found in all immune response cell types: thus leptin may link nutritional status, energy balance and immune function. Sleep loss, partial or chronic, is linked to decreased immune function. Obesity is a factor in obstructive sleep apnoea, which significantly reduces sleep duration and quality.