52 research outputs found

    Bioformers: Embedding Transformers for Ultra-Low Power sEMG-based Gesture Recognition

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    Human-machine interaction is gaining traction in rehabilitation tasks, such as controlling prosthetic hands or robotic arms. Gesture recognition exploiting surface electromyographic (sEMG) signals is one of the most promising approaches, given that sEMG signal acquisition is non-invasive and is directly related to muscle contraction. However, the analysis of these signals still presents many challenges since similar gestures result in similar muscle contractions. Thus the resulting signal shapes are almost identical, leading to low classification accuracy. To tackle this challenge, complex neural networks are employed, which require large memory footprints, consume relatively high energy and limit the maximum battery life of devices used for classification. This work addresses this problem with the introduction of the Bioformers. This new family of ultra-small attention-based architectures approaches state-of-the-art performance while reducing the number of parameters and operations of 4.9x. Additionally, by introducing a new inter-subjects pre-training, we improve the accuracy of our best Bioformer by 3.39%, matching state-of-the-art accuracy without any additional inference cost.Deploying our best performing Bioformer on a Parallel, Ultra-Low Power (PULP) microcontroller unit (MCU), the GreenWaves GAP8, we achieve an inference latency and energy of 2.72 ms and 0.14 mJ, respectively, 8.0x lower than the previous state-of-the-art neural network, while occupying just 94.2 kB of memory

    Additive effects of beta-alanine and sodium bicarbonate on high-intensity upper-body intermittent performance

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    We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) = (6.4 g day-1) was ingested for 4 weeks and 500 mg kg-1 BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation, the athletes completed four 30-s upper-body Wingate tests, separated by 3 min. Blood lactate was determined at rest, immediately after and 5 min after the 4th exercise bout, with perceived exertion reported immediately after the 4th bout. BA and SB alone increased the total work done in +7 and 8 %, respectively. The co-ingestion resulted in an additive effect (+14 %, p < 0.05 vs. BA and SB alone). BA alone significantly improved mean power in the 2nd and 3rd bouts and tended to improve the 4th bout. SB alone significantly improved mean power in the 4th bout and tended to improve in the 2nd and 3rd bouts. BA+SB enhanced mean power in all four bouts. PL+PL did not elicit any alteration on mean and peak power. Post-exercise blood lactate increased with all treatments except with PL+PL. Only BA+ SB resulted in lower ratings of perceived exertion (p = 0.05). Chronic BA and SB supplementation alone equally enhanced high-intensity intermittent upper-body performance in well-trained athletes. Combined BA and SB promoted a clear additive ergogenic effect

    The influence of a consumer-wearable activity tracker on sedentary time and prolonged sedentary bouts: secondary analysis of a randomized controlled trial

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    Abstract Objective A recent meta-analysis surmised pedometers were a useful panacea to independently reduce sedentary time (ST). To further test and expand on this deduction, we analyzed the ability of a consumer-wearable activity tracker to reduce ST and prolonged sedentary bouts (PSB). We originally conducted a 12-month randomized control trial where 800 employees from 13 organizations were assigned to control, activity tracker, or one of two activity tracker plus incentive groups designed to increase step count. The primary outcome was accelerometer measured moderate-to-vigorous physical activity. Results We conducted a secondary analysis on accelerometer measured daily ST and PSB bouts. A general linear mixed model was used to examine changes in ST and prolonged sedentary bouts, followed by between-group pairwise comparisons. Regression analyses were conducted to examine the association of changes in step counts with ST and PSB. The changes in ST and PSB were not statistically significant and not different between the groups (P < 0.05). Increases in step counts were concomitantly associated with decreases in ST and PSB, regardless of intervention (P < 0.05). Caution should be taken when considering consumer-wearable activity trackers as a means to reduce sedentary behavior. Trial registration NCT01855776 Registered: August 8, 201

    Skeletal muscle wasting and renewal: a pivotal role of myokine IL-6

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    The effects of two different doses of calcium lactate on blood pH, bicarbonate, and repeated high-intensity exercise performance

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    We investigated the effects of low- and high-dose calcium lactate supplementation on blood pH and bicarbonate (Study A) and on repeated high-intensity performance (Study B). In Study A, 10 young, physically active men (age: 24 ± 2.5 years; weight: 79.2 ± 9.45 kg; height: 1.79 ± 0.06 m) were assigned to acutely receive three different treatments, in a crossover fashion: high-dose calcium lactate (HD: 300 mg·kg−1 body mass), low-dose calcium lactate (LD: 150 mg·kg−1 body mass) and placebo (PL). During each visit, participants received one of these treatments and were assessed for blood pH and bicarbonate 0, 60, 90, 120, 150, 180, and 240 min following ingestion. In Study B, 12 young male participants (age: 26 ± 4.5 years; weight: 82.0 ± 11.0 kg; height: 1.81 ± 0.07 m) received the same treatments of Study A. Ninety minutes after ingestion, participants underwent 3 bouts of the upper-body Wingate test and were assessed for blood pH and bicarbonate 0 and 90 min following ingestion and immediately after exercise. In Study A, both HD and LD promoted slight but significant increases in blood bicarbonate (31.47 ± 1.57 and 31.69 ± 1.04 mmol·L−1, respectively) and pH levels (7.36 ± 0.02 and 7.36 ± 0.01, respectively), with no effect of PL. In Study B, total work done, peak power, mean power output were not affected by treatments. In conclusion, low- and high-dose calcium lactate supplementation induced similar, yet very discrete, increases in blood pH and bicarbonate, which were not sufficiently large to improve repeated high-intensity performance.</jats:p

    The liposuction-induced effects on adiponectin and selected cytokines are not affected by exercise training in women

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    It has been suggested that the abrupt liposuction-induced decrease in adipose tissue could affect adipokine secretion pattern. We hypothesized that exercise training could positively impact adipokine metabolism following liposuction. The aim of this study was to investigate the effects of liposuction on inflammation-related adipokines in women who were either exercise-trained or remained sedentary after surgery. Thirty-six healthy normal-weight women underwent an abdominal liposuction and two months after surgery were randomly allocated into two groups: trained (TR, n=18, four-month exercise program) and nontrained (NT, n=18). Inflammation-related adipokine serum levels (TNF-α, IL-6, IL-10, and adiponectin) and abdominal and thigh subcutaneous adipose tissue (scAT) mRNA levels were assessed before (PRE) and six months after surgery (POST6). TNF-α, IL-6, and IL-10 serum levels were unchanged in both groups. In contrast, TNF-α, IL-6, and IL-10 mRNA levels in scAT were increased, whereas adiponectin scAT mRNA and serum levels were decreased at POST6 (P<0.05, main effect for time). No changes were observed in mRNA levels of MCP-1, CD14, and CD68 in any of the groups. In conclusion, liposuction downregulates adiponectin scAT gene expression and serum levels and upregulates scAT gene expression of inflammation-related genes six months after surgery in normal-weight women, irrespective of exercise training

    A randomized controlled trial to reduce sedentary time in rheumatoid arthritis: Protocol and rationale of the Take a STAND for Health study

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    Background: Patients with rheumatoid arthritis spend most of their daily hours in sedentary behavior (sitting), a predisposing factor to poor health-related outcomes and all-cause mortality. Interventions focused on reducing sedentary time could be of novel therapeutic relevance. However, studies addressing this topic remain scarce. We aim to investigate the feasibility and efficacy of a newly developed intervention focused on reducing sedentary time, and potential clinical, physiological, metabolic and molecular effects in rheumatoid arthritis. Methods: The Take a STAND for Health study is a 4-month, parallel-group, randomized controlled trial, in which postmenopausal patients with rheumatoid arthritis will set individually tailored, progressive goals to replace their sedentary time with standing and light-intensity activities. Patients will be recruited from the Clinical Hospital (School of Medicine, University of Sao Paulo) and will be assessed at baseline and after a 4-month follow up. Outcomes will include objectively measured sedentary behavior (primary outcome) and physical activity levels, clinical parameters, anthropometric parameters and body composition; aerobic fitness, muscle function, blood pressure, cardiovascular autonomic function, vascular function and structure, health-related quality of life, and food intake. Blood and muscle samples will be collected for assessing potential mechanisms, through targeted and non-targeted approaches. Discussion: Findings will be of scientific and clinical relevance with the potential to inform new prescriptions focused on reducing sedentary behavior, a modifiable risk factor that thus far has been overlooked in patients with rheumatoid arthritis

    Acute cardiometabolic effects of brief active breaks in sitting for patients with rheumatoid arthritis

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    Exercise is a treatment in rheumatoid arthritis, but participation in moderate-to-vigorous exercise is challenging for some patients. Light-intensity breaks in sitting could be a promising alternative. We compared the acute effects of active breaks in sitting with those of moderate-to-vigorous exercise on cardiometabolic risk markers in patients with rheumatoid arthritis. In a crossover fashion, 15 women with rheumatoid arthritis underwent three 8-h experimental conditions: prolonged sitting (SIT), 30-min bout of moderate-to-vigorous exercise followed by prolonged sitting (EX), and 3-min bouts of light-intensity walking every 30 min of sitting (BR). Postprandial glucose, insulin, c-peptide, triglycerides, cytokines, lipid classes/subclasses (lipidomics), and blood pressure responses were assessed. Muscle biopsies were collected following each session to assess targeted proteins/genes. Glucose [-28% in area under the curve (AUC), P = 0.036], insulin (-28% in AUC, P = 0.016), and c-peptide (-27% in AUC, P = 0.006) postprandial responses were attenuated in BR versus SIT, whereas only c-peptide was lower in EX versus SIT (-20% in AUC, P = 0.002). IL-1b decreased during BR, but increased during EX and SIT (P = 0.027 and P = 0.085, respectively). IL-1ra was increased during EX versus BR (P = 0.002). TNF-a concentrations decreased during BR versus EX (P = 0.022). EX, but not BR, reduced systolic blood pressure (P = 0.013). Lipidomic analysis showed that 7 of 36 lipid classes/subclasses were significantly different between conditions, with greater changes being observed in EX. No differences were observed for protein/gene expression. Brief active breaks in sitting can offset markers of cardiometabolic disturbance, which may be particularly useful for patients who may find it difficult to adhere to exercise
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