Browse

You are looking at 41 - 50 of 515 items for :

  • Sport and Exercise Science/Kinesiology x
  • User-accessible content x
Clear All
Open access

Juliana S. Oliveira, Marina B. Pinheiro, Nicola Fairhall, Sarah Walsh, Tristan Chesterfield Franks, Wing Kwok, Adrian Bauman and Catherine Sherrington

Background: Frailty and sarcopenia are common age-related conditions associated with adverse outcomes. Physical activity has been identified as a potential preventive strategy for both frailty and sarcopenia. The authors aimed to investigate the association between physical activity and prevention of frailty and sarcopenia in people aged 65 years and older. Methods: The authors searched for systematic reviews (January 2008 to November 2019) and individual studies (January 2010 to March 2020) in PubMed. Eligible studies were randomized controlled trials and longitudinal studies that investigated the effect of physical activity on frailty and/or sarcopenia in people aged 65 years and older. The Grading of Recommendations Assessment, Development and Evaluation approach was used to rate certainty of evidence. Results: Meta-analysis showed that physical activity probably prevents frailty (4 studies; frailty score pooled standardized mean difference, 0.24; 95% confidence interval, 0.04–0.43; P = .017, I2 = 57%, moderate certainty evidence). Only one trial investigated physical activity for sarcopenia prevention and did not provide conclusive evidence (risk ratio 1.08; 95% confidence interval, 0.10–12.19). Five observational studies showed positive associations between physical activity and frailty or sarcopenia prevention. Conclusions: Physical activity probably prevents frailty among people aged 65 years and older. The impact of physical activity on the prevention of sarcopenia remains unknown, but observational studies indicate the preventive role of physical activity.

Open access

Kristin Suorsa, Anna Pulakka, Tuija Leskinen, Jaana Pentti, Andreas Holtermann, Olli J. Heinonen, Juha Sunikka, Jussi Vahtera and Sari Stenholm

Background: The accuracy of wrist-worn accelerometers in identifying sedentary time has been scarcely studied in free-living conditions. The aim of this study was to compare daily sedentary time estimates between a thigh-worn accelerometer, which measured sitting and lying postures, and a wrist-worn accelerometer, which measured low levels of movement. Methods: The study population consisted of 259 participants (M age = 62.8 years, SD = 0.9) from the Finnish Retirement and Aging Study (FIREA). Participants wore an Axivity AX3 accelerometer on their mid-thigh and an Actigraph wActiSleep-BT accelerometer on their non-dominant wrist simultaneously for a minimum of 4 days in free-living conditions. Two definitions to estimate daily sedentary time were used for data from the wrist-worn accelerometer: 1) the count cutpoint, ≤1853 counts per minute; and 2) the Euclidean Norm Minus One (ENMO) cutpoint, <30 mg. Results: Compared to the thigh-worn accelerometer, daily sedentary time estimate was 63 min (95% confidence interval [CI] = −53 to −73) lower by the count cutpoint and 50 min (95% CI = 34 to 67) lower by the ENMO cutpoint. The limits of agreement in daily sedentary time estimates between the thigh- and cutpoint methods for wrist-worn accelerometers were wide (the count cutpoint: −117 to 243, the ENMO cutpoint: −212 to 313 min). Conclusions: Currently established cutpoint-based methods to estimate sedentary time from wrist-worn accelerometers result in underestimation of daily sedentary time compared to posture-based estimates of thigh-worn accelerometers. Thus, sedentary time estimates obtained from wrist-worn accelerometers using currently available cutpoint-based methods should be interpreted with caution and future work is needed to improve their accuracy.

Open access

Andreas M. Kasper, S. Andy Sparks, Matthew Hooks, Matthew Skeer, Benjamin Webb, Houman Nia, James P. Morton and Graeme L. Close

Rugby is characterized by frequent high-intensity collisions, resulting in muscle soreness. Players consequently seek strategies to reduce soreness and accelerate recovery, with an emerging method being cannabidiol (CBD), despite anti-doping risks. The prevalence and rationale for CBD use in rugby has not been explored; therefore, we recruited professional male players to complete a survey on CBD. Goodness of fit chi-square (χ2) was used to assess CBD use between codes and player position. Effects of age on use were determined using χ2 tests of independence. Twenty-five teams provided 517 player responses. While the majority of players had never used CBD (p < .001, V = 0.24), 26% had either used it (18%) or were still using it (8%). Significantly more CBD use was observed in rugby union compared with rugby league (p = .004, V = 0.13), but player position was not a factor (p = .760, V = 0.013). CBD use increased with players’ age (p < .001, V = 0.28), with mean use reaching 41% in the players aged 28 years and older category (p < .0001). The players using CBD primarily used the Internet (73%) or another teammate (61%) to obtain information, with only 16% consulting a nutritionist. The main reasons for CBD use were improving recovery/pain (80%) and sleep (78%), with 68% of players reporting a perceived benefit. These data highlight the need for immediate education on the risks of CBD, as well as the need to explore the claims regarding pain and sleep.

Open access

Benjamin J. Narang, Greg Atkinson, Javier T. Gonzalez and James A. Betts

The analysis of time series data is common in nutrition and metabolism research for quantifying the physiological responses to various stimuli. The reduction of many data from a time series into a summary statistic(s) can help quantify and communicate the overall response in a more straightforward way and in line with a specific hypothesis. Nevertheless, many summary statistics have been selected by various researchers, and some approaches are still complex. The time-intensive nature of such calculations can be a burden for especially large data sets and may, therefore, introduce computational errors, which are difficult to recognize and correct. In this short commentary, the authors introduce a newly developed tool that automates many of the processes commonly used by researchers for discrete time series analysis, with particular emphasis on how the tool may be implemented within nutrition and exercise science research.

Full access

Daniel H. Aslan, Joshua M. Collette and Justus D. Ortega

The decline of walking performance is a key determinant of morbidity among older adults. Healthy older adults have been shown to have a 15–20% lower walking economy compared with young adults. However, older adults who run for exercise have a higher walking economy compared with older adults who walk for exercise. Yet, it remains unclear if other aerobic exercises yield similar improvements on walking economy. The purpose of this study was to determine if regular bicycling exercise affects walking economy in older adults. We measured metabolic rate while 33 older adult “bicyclists” or “walkers” and 16 young adults walked on a level treadmill at four speeds between (0.75–1.75 m/s). Across the range of speeds, older bicyclists had a 9–17% greater walking economy compared with older walkers (p = .009). In conclusion, bicycling exercise mitigates the age-related deterioration of walking economy, whereas walking for exercise has a minimal effect on improving walking economy.

Full access

Karl M. Newell

A review and synthesis of the literature on the learning and development of motor skills supports the postulation that whether a motor skill can be deemed fundamental is dependent on the collective presence of three conditions: (i) uniqueness to the movement pattern and/or outcome; (ii) near universality of the functional outcome in the healthy population; (iii) capacity to act as an antecedent influence supporting generalization to a large and broad set of perceptual-motor skills. Within this framework, it is proposed that the infant motor development sequence underpinning upright posture (e.g., sitting, bipedal standing), locomotion (e.g., walking, running), and object-interaction (e.g., grasping) represents the minimum set of fundamental motor skills from which all other skills evolve with over the lifespan. This position is in contrast to the views of many students of motor development and learning who describe numerous skills that typically emerge in the ∼2- to 18-year-old range as fundamental but do not meet the criteria outlined here to be fundamental. It is proposed that these be labeled as core developmental activities having a more restricted but still practically relevant influence on the acquisition of and generalization to other motor skills.

Full access

Dirk Krombholz, Luca Daniel, Peter Leinen, Thomas Muehlbauer and Stefan Panzer

The main purpose of this study was to determine the covariation of anthropometric parameters and the center of pressure (CoP) of young soccer players. Sub-elite young male players between 16 and 17 years (N = 42) were instructed to perform single-leg balance tasks under different conditions: static and dynamic balance on firm and foam ground. Single-leg balance was measured with a Kistler force plate. The measures of postural control were the CoP displacement in anterior-posterior and medio-lateral directions. Further, the following anthropometric variables were assessed: body height, body weight, foot length, and foot width. Results indicated only two small-sized correlations between body height/weight and the CoP measures. The covariation between body height, body weight, and the CoP measures for the single-leg stance in young male sub-elite soccer players was less than 10%.

Open access

Andy J. King, Joshua T. Rowe and Louise M. Burke

The benefits of ingesting exogenous carbohydrate (CHO) during prolonged exercise performance are well established. A recent food technology innovation has seen sodium alginate and pectin included in solutions of multiple transportable CHO, to encapsulate them at pH levels found in the stomach. Marketing claims include enhanced gastric emptying and delivery of CHO to the muscle with less gastrointestinal distress, leading to better sports performance. Emerging literature around such claims was identified by searching electronic databases; inclusion criteria were randomized controlled trials investigating metabolic and/or exercise performance parameters during endurance exercise >1 hr, with CHO hydrogels versus traditional CHO fluids and/or noncaloric hydrogels. Limitations associated with the heterogeneity of exercise protocols and control comparisons are noted. To date, improvements in exercise performance/capacity have not been clearly demonstrated with ingestion of CHO hydrogels above traditional CHO fluids. Studies utilizing isotopic tracers demonstrate similar rates of exogenous CHO oxidation, and subjective ratings of gastrointestinal distress do not appear to be different. Overall, data do not support any metabolic or performance advantages to exogenous CHO delivery in hydrogel form over traditional CHO preparations; although, one study demonstrates a possible glycogen sparing effect. The authors note that the current literature has largely failed to investigate the conditions under which maximal CHO availability is needed; high-performance athletes undertaking prolonged events at high relative and absolute exercise intensities. Although investigations are needed to better target the testimonials provided about CHO hydrogels, current evidence suggests that they are similar in outcome and a benefit to traditional CHO sources.