Extensive Familiarization Is Required Before Assessing Acute Changes in Multiple Object Tracking Performance.

CONTEXT: The Neurotracker CORE assessment is an 8-minute multiple object tracking (MOT) program used in sport science research and clinical rehabilitation as a perceptual-cognitive training tool; however, it has garnered interest for its potential use as an acute assessment of cognitive performance. Although some data exist regarding the learning effect of repeated exposures, it is often overlooked with investigators focusing primarily on the presence of transfer effects to other cognitive realms. As a result, exclusive data on the effect of repeated testing, or subsequent periods of no testing (ie, detraining) on test-retest reliability, and on MOT performance are sparse. DESIGN: Repeated-measures/reliability. METHODS: Twenty-three recreationally active men and women completed 15 training sessions consisting of 2 CORE assessments per session (30 assessments). Participants were randomized to either 1 or 2 weeks of detraining prior to completing 15 retraining sessions (30 assessments). Training and retraining periods were divided into 10 blocks (3 assessments/block) for analysis. MOT speed threshold (MOT-ST), consistency, fastest trial score success speed, lowest trial score miss speed, the number of perfect, near misses, and significant miss trials within each block were used to determine performance. Intraclass correlation coefficient, standard error of measurement, and minimal detectable change were used to determine reliability. RESULTS: Significant improvements in MOT-ST and fastest trial score success speed were noted within training blocks 1 to 6 and 1 to 7, respectively (P < .05). MOT-ST and fastest trial score success speed demonstrated excellent test-retest reliability between blocks 8 and 9. There was no effect of detraining period on performance during retraining. CONCLUSIONS: Eighteen tests are necessary to overcome training effects and establish a reliable baseline when MOT-ST is used as the performance outcome. Detraining periods up to 2 weeks did not impact performance. The average of 3 discrete tests should be used when assessing MOT-ST performance.

Evaluating the effects of PeakATP® supplementation on visuomotor reaction time and cognitive function following high-intensity sprint exercise.

The purpose of this study was to examine the effects of 14-days adenosine 5'-triphosphate (ATP) supplementation (PeakATP®) on reaction time (RT), multiple object tracking speed (MOT), mood and cognition. Twenty adults (22.3 ± 4.4 yrs., 169.9 ± 9.5 cm, 78.7 ± 14.6 kg) completed two experimental trials in a double-blind, counter-balanced, crossover design. Subjects were randomized to either PeakATP® (400 mg) or placebo (PLA) and supplemented for 14-days prior to each trial. During each trial, subjects completed a three-minute all-out test on a cycle ergometer (3MT), with measures of visuomotor RT [Dynavision D2 Proactive (Mode A) and Reactive (Mode B) tasks], MOT (Neurotracker), mood (Profile of Mood States Questionnaire; POMS) and cognition (Automated Neuropsychological Assessment Metrics; ANAM) occurring before (PRE), immediately post (IP) and 60 min post-3MT (60P). Subjects ingested an acute dose of the assigned supplement 30 min prior to completing PRE assessments for each trial. Trials were separated by a 14-day washout period. PeakATP® significantly attenuated declines in hits (p = 0.006, ηp2 = 0.235) and average RT (AvgRT, p = 0.006, ηp2 = 0.236) in Mode A, significantly improved AvgRT (p = 0.039, ηp2 = 0.174) in Mode B, and significantly reduced the total number of misses (p = 0.005, ηp2 = 0.343) in Mode B. No differences between treatments were noted for MOT, POMS or ANAM variables. In conclusion, these results indicate that PeakATP® maintains proactive RT and improves reactive RT following high-intensity sprint exercise suggesting that supplemental ATP may mitigate exercise induced cognitive dysfunction.

The Effects of Two Weeks of Oral PeakATP® Supplementation on Performance during a Three-Minute All out Test.

Exogenous ATP has been shown to increase total weight lifted during resistance training interventions and attenuate fatigue during repeated Wingate assessments. However, the influence of exogenous ATP on single bout maximal effort performance has yet to be examined. The purpose of this study was to investigate the effects of PeakATP® supplementation on performance during a 3-min all-out test (3MT). Twenty adults (22.3 ± 4.4 years, 169.9 ± 9.5 cm, 78.7 ± 14.6 kg) completed two identical 3MT protocols in a double-blind, counter-balanced, crossover design. Participants were randomized to either PeakATP® (400 mg·day-1) or placebo (PLA) treatments and consumed their assigned supplement for 14 days and ingested an acute dose 30 min before each 3MT. A 14-day wash-out period was completed between each supplementation period and subsequent 3MT. Peak power, time to peak power, work above end power, end power, and fatigue index were assessed during each 3MT. Dependent t-tests and Hedge's g effect sizes were used to assess differences between treatments. No significant differences were observed between treatments for 3MT performance (p > 0.05). These findings indicate that 3MT performance was not significantly impacted by PeakATP® supplementation. This may be due in part to the continuous nature of the 3MT as disodium ATP has been shown to be beneficial for repeated bout activities.

The relationship between digit ratio (2D:4D) and muscular fitness: A systematic review and meta-analysis.

BACKGROUND: Digit ratio (2D:4D), a marker of prenatal testosterone exposure, is a weak negative correlate of sports/athletic/fitness performance. While numerous studies have examined the relationship between 2D:4D and physical fitness, there has never been a comprehensive study that has synthesized studies examining relationships between 2D:4D and muscular fitness. OBJECTIVES: To systematically review and meta-analyze the relationship between 2D:4D and muscular fitness measured as handgrip strength (HGS). METHODS: We systematically searched five electronic databases, reference lists, topical systematic reviews/meta-analyses, and personal libraries in November 2020. Peer-reviewed, cross-sectional studies that reported Pearson's correlation coefficients between objectively measured 2D:4D and HGS were included. We used random-effects meta-analysis to estimate the pooled correlation and the 95% confidence interval (95%CI), and moderator analyses to estimate the influence of sex and age. RESULTS: Data from 22 studies, representing 5271 individuals from 11 countries ranging in (mean) age from 10.4 to 58.0 years, were included. Overall, there was a weak negative correlation between 2D:4D and HGS (r = -0.15, 95%CI = -0.20 to -0.09), indicating that individuals with low 2D:4Ds had high HGS. We found substantial heterogeneity between studies (Q = 123.4, p < .0001; I2  = 74%), but neither sex (Q = 0.003, p = .96) nor age (Q = 0.46, p = .50) significantly moderated the pooled correlation. CONCLUSIONS: We found a weak negative relationship between 2D:4D and HGS, which showed substantial heterogeneity between studies, but was neither moderated by sex nor age. Our finding probably reflects both the long-term (organizational) and short-term (activational) benefits of testosterone.

Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017.

BACKGROUND: The 6-minute walking distance (6MWD) is an excellent measure of both functional endurance and health. The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017; the secondary aim was to estimate concurrent trends in body size (i.e., height and mass) and self-reported participation in exercise/sport. METHODS: Adults aged 65-79 years were included. Annual nationally representative 6MWD data (n = 103,505) for the entire period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in means (and relative frequencies) were estimated at the gender-age level by best-fitting sample-weighted linear/polynomial regression models, with national trends estimated by a post-stratified population-weighting procedure. Temporal trends in distributional variability were estimated as the ratio of coefficients of variation. RESULTS: Between 1998 and 2017 there was a steady, moderate improvement in mean 6MWD (absolute = 45 m (95% confidence interval (95%CI): 43-47); percent = 8.0% (95%CI: 7.6%-8.4%); effect size = 0.51 (95%CI: 0.48-0.54)). Gender- and age-related temporal differences in means were negligible. Variability in 6MWD declined substantially (ratio of coefficients of variation = 0.89, 95%CI: 0.87-0.92), with declines larger for women compared to men, and for 75-79-year-olds compared to 65-74-year-olds. Correspondingly, there were moderate and negligible increases in mean height and mass, respectively, and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session. CONCLUSION: There has been a steady, moderate improvement in mean 6MWD for older Japanese adults since 1998, which is suggestive of corresponding improvements in both functional endurance and health. The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution. Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.

Effects of Exercise Training on Resting Testosterone Concentrations in Insufficiently Active Men: A Systematic Review and Meta-Analysis.

ABSTRACT: Potter, NJ, Tomkinson, GR, Dufner, TJ, Walch, TJ, Roemmich, JN, Wilson, PB, and Fitzgerald, JS. Effects of exercise training on resting testosterone concentrations in insufficiently active men: a systematic review and meta-analysis. J Strength Cond Res 35(12): 3521-3528, 2021-The anabolic hormone testosterone plays a pivotal role in the healthy aging of men and tends to decline with age. The aims of this systematic review and meta-analysis were 2-fold: (a) to evaluate the effect of exercise training on resting total testosterone concentration in insufficiently active, apparently healthy men and (b) to determine whether the effects of exercise training differed by training mode, age, body mass status, or testosterone measure. Electronic databases (MEDLINE, Scopus, CINAHL, and SPORTDiscus) were systematically searched (up to and including October 22, 2020) for peer-reviewed randomized controlled trials (RCTs) meeting the following criteria: population (insufficiently active, apparently healthy men aged ≥18 years), intervention (exercise training [any modality at intensity of ≥4 metabolic equivalents] lasting a minimum of 4 weeks), control (insufficiently active men), and outcome (resting total testosterone concentration). Intervention effects, weighted by the inverse of the pooled variance, were calculated relative to the control group as standardized mean differences (SMDs). Eleven RCTs, representing 421 insufficiently active, apparently healthy men aged 19-75 years across 16 intervention groups who participated in aerobic, resistance, or combined training lasting a median of 12 weeks, were included in the analysis. Overall, exercise training had a negligible effect on resting total testosterone concentration (mean SMD [95% CI]: 0.00 [-0.20 to 0.20]). Subgroup analyses indicated that the effect of exercise training was not significantly affected by training mode, age, body mass status, or testosterone measure. Exercise training does not seem to affect resting total or free testosterone concentration in insufficiently active, eugonadal men.

Temporal Trends in the Handgrip Strength of 2,592,714 Adults from 14 Countries Between 1960 and 2017: A Systematic Analysis.

BACKGROUND: Handgrip strength (HGS) is an excellent marker of functional capability and health in adults, although little is known about temporal trends in adult HGS. OBJECTIVES: The aim of this study was to systematically analyze national (country-level) temporal trends in adult HGS, and to examine the relationships between national trends in adult HGS and national trends in health-related and socioeconomic/demographic indicators. METHODS: Data were obtained from a systematic search of studies reporting temporal trends in HGS for adults (aged ≥ 20 years) and by examining national fitness datasets. Trends in mean HGS were estimated at the country-sex-age group level by best-fitting sample-weighted linear/polynomial regression models, with national and sub-regional (pooled data across geographically similar countries) trends estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in adult HGS and national trends in health-related and socioeconomic/demographic indicators. RESULTS: Data from ten studies/datasets were extracted to estimate trends in mean HGS for 2,592,714 adults from 12 high- and 2 upper-middle-income countries (from Asia, Europe and North America) between 1960 and 2017. National trends were few, mixed and generally negligible pre-2000, whereas most countries (75% or 9/12) experienced negligible-to-small declines ranging from an effect size of 0.05 to 0.27, or 0.6 to 6.3%, per decade post-2000. Sex- and age-related temporal differences were negligible. National trends in adult HGS were not significantly related to national trends in health and socioeconomic/demographic indicators. CONCLUSIONS: While trends in adult HGS are currently limited to 14 high- and upper-middle-income countries from three continents, adult HGS appears to have declined since 2000 (at least among most of the countries in this analysis), which is suggestive of corresponding declines in functional capability and health. PROSPERO REGISTRATION NUMBER: CRD42013003678.