The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

Background/objective The relationship between ventilatory threshold (VT1, VT2) and repeated-sprint ability (RSA) in competitive male ice hockey players was investigated. Methods Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙ role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 14.4px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative; \u3eV˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope). Participants performed an on-ice repeated shift (RSA) test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec). Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2) and RSA (first gate, second gate, and total course decrement). Results Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P \u3c 0.05), second gate (r = −0.58; P \u3c 0.001) and total course decrement (r = −0.42; P \u3c 0.05). Conclusion The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙ role= presentation style= box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 14.4px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative; \u3eV˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA

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 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 10 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 3 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. KEY POINTS National (country-level) trends in adult handgrip strength (HGS) were few, mixed and generally negligible pre-2000, and generally negligible and indicated declines post-2000 Sex- and age-related temporal differences in adult HGS were negligible-to-small at the country level and negligible at the regional level National trends in adult HGS were not significantly related to national trends in health and socioeconomic/demographic indicator

Review of criterion-referenced standards for cardiorespiratory fitness: what percentage of 1 142 026 international children and youth are apparently healthy?

Purpose To identify criterion-referenced standards for cardiorespiratory fitness (CRF); to estimate the percentage of children and youth that met each standard; and to discuss strategies to help improve the utility of criterion-referenced standards for population health research. Methods A search of four databases was undertaken to identify papers that reported criterion-referenced CRF standards for children and youth generated using the receiver operating characteristic curve technique. A pseudo-dataset representing the 20-m shuttle run test performance of 1 142 026 children and youth aged 9–17 years from 50 countries was generated using Monte Carlo simulation. Pseudo-data were used to estimate the international percentage of children and youth that met published criterion-referenced standards for CRF. Results Ten studies reported criterion-referenced standards for healthy CRF in children and youth. The mean percentage (±95% CI) of children and youth that met the standards varied substantially across age groups from 36%±13% to 95%±4% among girls, and from 51%±7% to 96%±16% among boys. There was an age gradient across all criterion-referenced standards where younger children were more likely to meet the standards compared with older children, regardless of sex. Within age groups, mean percentages were more precise (smaller CI) for younger girls and older boys. Conclusion There are several CRF criterion-referenced standards for children and youth producing widely varying results. This study encourages using the interim international criterion-referenced standards of 35 and 42 mL/kg/min for girls and boys, respectively, to identify children and youth at risk of poor health—raising a clinical red flag

The 20-m shuttle run: Assessment and interpretation of data in relation to youth aerobic fitness and health

Cardiorespiratory fitness (CRF) is a good summative measure of the body’s ability to perform continuous, rhythmic, dynamic, large-muscle group physical activity, and exercise. In children, CRF is meaningfully associated with health, independent of physical activity levels, and it is an important determinant of sports and athletic performance. Although gas-analyzed peak oxygen uptake is the criterion physiological measure of children’s CRF, it is not practical for population-based testing. Field testing offers a simple, cheap, practical alternative to gas analysis. The 20-m shuttle run test (20mSRT)—a progressive aerobic exercise test involving continuous running between 2 lines 20 m apart in time to audio signals—is probably the most widely used field test of CRF. This review aims to clarify the international utility of the 20mSRT by synthesizing the evidence describing measurement variability, validity, reliability, feasibility, and the interpretation of results, as well as to provide future directions for international surveillance. The authors show that the 20mSRT is an acceptable, feasible, and scalable measure of CRF and functional/exercise capacity, and that it has moderate criterion validity and high to very high reliability. The assessment is pragmatic, easily interpreted, and results are transferable to meaningful and understandable situations. The authors recommend that CRF, assessed by the 20mSRT, be considered as an international population health surveillance measure to provide additional insight into pediatric population health

Test-retest reliability of TRIMP in collegiate ice hockey players

The utility of the heart rate derived variable TRaining IMPulse (TRIMP) for assessing internal training load in ice hockey players is not clear. Having a reliable measure of internal training load during on-ice training sessions would help coaches program exercise training. This study determined the reliability of TRIMP during on-ice training sessions in ice hockey players. Twelve Division I collegiate male ice hockey players (aged 18–23 years) had their heart rate (HR) data recorded during two on-ice practice sessions separated by two weeks. TRIMP and other descriptive HR variables were compared between sessions. TRIMP demonstrated moderate reliability during on-ice sessions. Systematic error, quantified as standardized change in means was negligible (–0.19); random error quantified as the percent typical error (%TE) was moderate (12.2%); and, test-retest correlation was very strong (0.75). TRIMP is suitable for quantifying training load during intermittent work in hockey athletes. The results from our study can be used to determine the threshold for meaningful change in TRIMP, which may aid in informing decisions by coaches and strength training staff regarding on-ice training session difficulty and composition

Utility of international normative 20 m shuttle run values for identifying youth at increased cardiometabolic risk

The purpose of this study was to examine the ability of international normative centiles for the 20 m shuttle run test (20mSRT) to identify youth at increased cardiometabolic risk. This was a cross-sectional study involving 961 children aged 10–17 years (53% girls) from the United Kingdom. Receiver operating characteristic (ROC) curves determined the discriminatory ability of cardiorespiratory fitness percentiles for predicting increased cardiometabolic risk. ROC analysis demonstrated a significant but poor discriminatory accuracy of cardiorespiratory fitness in identifying low/high cardiometabolic risk in girls (AUC = 0.58, 95% CI: 0.54–0.63; p = 0.04), and in boys (AUC = 0.59, 95% CI: 0.54–0.63; p = 0.03). The cardiorespiratory fitness cut-off associated with high cardiometabolic risk was the 55th percentile (sensitivity = 33.3%; specificity = 84.5%) in girls and the 60th percentile (sensitivity = 42.9%; specificity = 73.6%) in boys. These 20mSRT percentile thresholds can be used to identify children and adolescents who may benefit from lifestyle intervention. Nonetheless, further work involving different populations and cardiometabolic risk scores comprising of different variables are needed to confirm our initial findings

Temporal trends in handgrip strength for older Japanese adults between 1998 and 2017

Objective: To estimate temporal trends in handgrip strength (HGS) for older Japanese adults between 1998 and 2017. Design and Methods: Adults aged 60–79 years were included. Annual nationally representative HGS data (n=176,449) for the 19-year study period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in mean HGS were estimated by sample-weighted regression models relating the year of testing to mean HGS. National trends in absolute, percent and standardized HGS were estimated by a post-stratified population-weighting procedure. Temporal trends in variability were estimated as the ratio of coefficients of variation (CVs). Results: Collectively, there was a small improvement in mean HGS of 1.4 kg (95%CI: 1.3–1.5), 4.5% (95%CI: 4.3–4.7), or 0.27 standard deviations (95%CI: 0.26–0.28) between 1998 and 2017. The rate of improvement progressively increased over time, with more recent values (post-2008) 1.5-fold larger than earlier values. Gender- and age-related temporal differences were negligible. Variability in HGS declined substantially over time (ratio of CVs [95%CI]: 0.88 [0.86–0.90]), with declines 1.9-fold larger in women compared to men, and 1.7-fold larger in 70–79-year-olds compared to 60–69-year-olds. Conclusions: There has been a small, progressive improvement in mean HGS for older Japanese adults since 1998, which is suggestive of a corresponding improvement in overall strength capacity. The substantial decline in variability indicates that the improvement in mean HGS was not uniform across the population

Temporal trends in the cardiorespiratory fitness of 2,525,827 adults between 1967 and 2016

Objective To estimate international and national temporal trends in the cardiorespiratory ftness (CRF) of adults, and to examine relationships between trends in CRF and trends in health-related, socioeconomic, and environmental indicators. Methods Data were obtained from a systematic search of studies that explicitly reported temporal trends in the CRF of apparently healthy adults aged 18–59 years. Sample-weighted temporal trends were estimated using best-ftting regression models relating the year of testing to mean CRF. Post-stratifed population-weighted mean changes in percent and standardized CRF were estimated. Pearson’s correlations were used to describe associations between linear trends in CRF and linear trends in health-related, socioeconomic, and environmental indicators. Results 2,525,827 adults representing eight high- and upper-middle-income countries between 1967 and 2016 collectively showed a moderate decline of 7.7% (95% CI −8.4 to −7.0) or 1.6% per decade (95% CI −1.7 to −1.5). Internationally, CRF improved in the 1960s and 1970s, and progressively declined at an increasing rate thereafter. Declines were larger for men than for women, and for young adults (\u3c40 \u3eyears) than for middle-aged adults (≥40 years). All countries experienced declines in CRF with a very strong negative correlation between CRF trends and obesity trends. Conclusions There has been a meaningful decline in the CRF of adults since 1980, which has progressively increased in magnitude over time, suggestive of a corresponding decline in population health. Continuous national and international surveillance systems are needed in order to monitor health and ftness trends, especially among low- and middle-income countries for which data do not currently exist. PROSPERO registration number: CRD42013003678