Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis

The purpose of this study was to use the meta-analytic approach to examine the effects of caffeine ingestion on ratings of perceived exertion (RPE). Twenty-one studies with 109 effect sizes (ESs) met the inclusion criteria. Coding incorporated RPE scores obtained both during constant load exercise (n=89) and upon termination of exhausting exercise (n=20). In addition, when reported, the exercise performance ES was also computed (n=16). In comparison to placebo, caffeine reduced RPE during exercise by 5.6% (95% CI (confidence interval), -4.5% to -6.7%), with an equivalent RPE ES of -0.47 (95% CI, -0.35 to -0.59). These values were significantly greater (P<0.05) than RPE obtained at the end of exercise (RPE % change, 0.01%; 95% CI, -1.9 to 2.0%; RPE ES, 0.00, 95% CI, -0.17 to 0.17). In addition, caffeine improved exercise performance by 11.2% (95% CI; 4.6-17.8%). Regression analysis revealed that RPE obtained during exercise could account for approximately 29% of the variance in the improvement in exercise performance. The results demonstrate that caffeine reduces RPE during exercise and this may partly explain the subsequent ergogenic effects of caffeine on performance.     

Effects of traditional balance and slackline training on physical performance and perceived enjoyment in young soccer players

The aim of this study was to evaluate the effects of 12-week balance and slackline training programs on physical performance and perceived enjoyment scale in young soccer players. Forty-one preadolescent soccer players were assigned to two experimental groups performing traditional balance (BLT) or slackline training (SLT), and a control group. Pre-post assessment encompassed Balance Error Scoring System (BESS), Star Excursion Balance test (SEBT), sprint with 90° turns (S90), and countermovement jump (CMJ). The rate of perceived enjoyment scale (PACES) was applied at the end of the experimental period. SLT and BLT improved similarly in BESS, SEBT and S90. No changes were detected in the CMJ. Regarding PACES score, SLT presented significantly higher values than BLT. Young athletes may benefit from a motivating training approach, thus, a designed program based on slackline drills should be preferable to improve physical performance in terms of balance and change of direction ability in preadolescent soccer players.     

Assessment of physical activity, fitness and performance in 76-year-olds

In a population study comprising 588 76-year-olds, the level of physical activity and physical performance, as well as associations between the variables included, was investigated. Men were significantly more active than women unless household activities were included in the physical activity scale, in which case no difference was found between men and women in the summer, whereas women were significantly more active than men in winter. In all performance variables (isometric knee extensor strength, stair-climbing and maximal walking speed) men had significantly higher values than women. Correlations between physical activity and physical performance were moderate, but still indicate that the scale is a valid one for assessing physical activity.     

The effect of age on between-match physical performance variability in professional soccer players

ABSTRACT

This study aimed to analyse the effect of age on between-match variability of physical performance in professional soccer players. For this purpose, observations on entire match performance were collected on 787 professional soccer players competing in the first or second division of Spanish league during the 2017–2018 season. Players were classified into six groups according to their age: G1 (≤22.5 years), G2 (22.6–25.1 years), G3 (25.2–27.5 years), G4 (27.6–30.1 years), G5 (30.2–33.1 years) and G6 (≥33.2 years). Coefficients of variation (CVs) were calculated individually for each player and performance variable: total distance, low- intensity, medium-intensity, high-intensity running (HIR), sprinting, number of HIR, number of sprints, average speed and maximal speed. The main finding of this study was that players under 25.2 years (G1 and G2) showed lower CVs for high-intensity activities (HIR and sprinting) in comparison with players over 33.1 years (G6). These findings provide useful information for soccer coaches, who could put extra attention on physical performance of the oldest players when they have to play an entire match, because their performance is more variable and uncertain in comparison with the youngest.     

Prediction of physical fitness and physical activity level in adulthood by physical performance and physical activity in adolescence - An 18-year follow-up study

Barnekow-Bergkvist M, Hedberg G, Janlert U, Jansson E. Prediction of physical fitness and physical activity level in adulthood by physical performance and physical activity in adolescence - An 18-year follow-up study. The aim of the study was to investigate relationships between physical fitness and self-reported physical activity in adulthood and to what extent the level of physical fitness and leisure-time physical activity in adulthood can be explained by anthropometric measures, physical performance, physical activity, attitudes to sports activities and socio-demographic characteristics at the age of 16. A group of 157 men and 121 women was tested at the ages of 16 and 34 by means of questionnaires and fitness tests. Physically active men and women had higher estimated VO_{2 max} and performed better in curl ups and bench press than those who were inactive. Performance in physical tests, height, weight and physical activity at the age of 16 contributed best to explain adult physical performance and physical activity. The magnitude of explanation varied between 10% (9-min run test) and 56% (bench press test); it was in general lower in the men than in the women. The various fitness tests and physical activity were explained by different predictors and the predictors also differed between men and women. The findings about attitudes to sports and socio-demographic factors at a young age that influence adult physical activity habits and fitness are very complex and further research is required to identify specific inactivity risks.     

Longitudinal associations of physical fitness and body mass index with academic performance

No studies have analyzed the longitudinal associations of change in physical fitness components and obesity with academic performance. The aim of the study was to examine longitudinal associations of changes in physical fitness components and body mass index with academic performance among youth, and whether the physical fitness components are moderators of the longitudinal association between obesity and academic performance in youth. Longitudinal analyses (2 years) included 1802 youths. Physical fitness components were assessed following the ALPHA health‐related fitness test battery. Academic performance was assessed via school records. Youth in the persistently high cardiorespiratory fitness and motor ability categories (ie, fit at baseline and at 2‐year follow‐up) had higher academic performance at follow‐up than those in the persistently low category. Further, youth with normal weight at baseline and overweight/obesity at follow‐up had lower academic performance scores at follow‐up compared to those with normal weight. Also, cardiorespiratory fitness may ameliorate the negative influence of excess body mass index on academic performance at follow‐up. Promoting physical activity programs at school that include both aerobic exercise and motor tasks to improve physical fitness and reduce body mass index may not only improve physical health, but also contribute toward successful academic development.     

The effect of interstate travel on the sleep patterns and performance of elite Australian Rules footballers.

This study examined the effect of interstate travel on sleep patterns and game performance of elite Australian Rules footballers. Nineteen members of a Western Australian-based Australian Football League team participated in the study during the 2004 season. Sleep was assessed on the night before home and away games by measuring sleep duration (SLD), sleep efficiency (SLE), wake time (WT) and number of wakings (NW) via actigraphy. Subjective sleep quality was assessed using a sleep rating (SR) scale. Baseline sleep measurements were obtained over four consecutive non-game nights. Game performance was assessed using a coach's rating (CR) scale and impact ranking (IR) and by player statistics including frequency of possessions (P) and frequency of possessions and team assists (PTA). Compared to baseline, SLD was greater on the nights before home and away games (by 48 and 39 min, respectively, p<0.05). Other sleep measures were unchanged. Sleep rating was poorer before away than home games (p<0.05). CR and IR were greater during home than away games (p<0.05). All other measures of performance were similar at home and away. These results show that prior interstate travel has minimal effect on sleep quality and game performance in elite footballers.     

The effect of callisthenic exercise on physical fitness values of sedentary women

Introduction

The purpose of this study was done to determine the effects of a 12-week callisthenic exercise program on some physical and physiological parameters of young, middle-aged and menopausal women.

Synthesis

We studied, during 12 weeks, 172 subjects’ age, height and body weight means were determined. Physical characteristics of Group I were (between19–30 years) 26.72 ± 3.57 years, 158.18 ± 4.66 cm and 71.45 ± 10.32 kg, for Group II (between 31–44 years) were as 41.43 ± 4.69 years, 156.94 ± 5.27 cm and 73,89 ± 10,66 kg, and Group III (between 45–56 years) were as 50.60 ± 4.05 years, 154.45 ± 4.18 cm and 75.51 ± 11.71 kg, respectively. All subjects attended the study, 50 minutes per session, three sessions per week, aerobic and calisthenic exercise programs. The intensity of the exercise was determined by Karvonen method (60 or 70%). There were significant differences in increase among aerobic power, sit-up, push-up, and handgrip strength values in Groups I, II and III. There was a significant difference among Group I, II and III in decreased blood pressure (p < 0.05).

Conclusion

It was determined that physical fitness values had decreased as the age increased. As a result, it can be said that the long-term callisthenic exercises cause the similar positive changes on women at different ages.     

Interactive effects of physical work and carbon monoxide on cognitive task performance

The simple and interactive effects of carbon monoxide (CO) exposure and prior physical work on cognitive performance were evaluated in 11 men and 7 women. Three levels of carboxyhemoglobin (HbCO) (0, 7, 10%) and three workloads (rest, 35%, 60% Vo2max) were crossed resulting in nine repeated measures conditions for each subject. Following bolus administration of CO, subjects exercised or rested for 50 min, then performed five cognitive tasks: Manikin spatial processing, Sternberg memory, Stroop word-color interference, visual search, and dual-axis tracking, with and without a secondary mathematics task. Carboxyhemoglobin levels were assessed after bolus administration and again following completion of the last task. Ambient CO levels were set to maintain the required HbCO levels in each condition. Performance on the second of two sequentially presented Stroop interference tasks (using identical stimuli but with instructions reversed) was impaired with increasing HbCO level, suggesting a reduced ability to adapt to a new response set. An interaction between HbCO level and exercise level was seen for visual search performance: in rest conditions, performance was improved with increasing HbCO level; by contrast, performance was impaired with increasing HbCO levels following 60% work. Elevated HbCO had no effect on spatial processing, short-term memory, simple reaction time, or psychomotor tracking.     

The psychophysiological influence of exertion and affect on sport-specific cognitive and physical performance

ObjectivesThe purpose of the present study was to examine differences in cognitive and physical performance, affective states, perceived exertion, and physiological responses between trials with cognitive, physical, or combined cognitive and physical load.DesignRandomised cross-over trial.MethodsHighly trained competitive orienteers (n = 15 men; n = 10 women) completed three randomised trials comprised of: (1) sport-specific cognitive tests; (2) 35-minute cycling time trial; and (3) combined sport-specific cognitive tests and 35-minute cycling time trial. Measures taken during the trials recorded affective states, perceived exertion, heart rate, blood lactate, cycling watts, as well as working memory, updating, planning and decision making.ResultsNo significant differences in cognitive performance accuracy were observed within or across trials although reaction times improved within trials and were fastest in the combined trial. Blood lactate, heart rate, perceived exertion, negative affective states, and watts were highest in the physical trial.ConclusionsThe combined load of undertaking sport-specific cognitive tests and a cycling time trial did not influence cognitive performance accuracy. Athletes produced greater watts when completing the physical task independently compared with the combined trial, however psychophysiological responses were worse. Further investigation is warranted to determine whether athletes' attentional focus underpins psychophysiological responses to dual-task sport performance.     

Aviation Rescue Firefighters physical fitness and predictors of task performance

ObjectivesAviation Rescue Firefighters (ARFF) require physical fitness specific to the aviation environment. This study aims to determine the physical fitness of ARFF and predictors of performance on ARFF-specific tasks from laboratory-based fitness measures.DesignCross-sectional, observational study.MethodsForty-two male ARFF (mean ± SD; age 38.4 ± 7.6 years, body mass index 26.2 ± 2.2 kg m⁻²) completed a physical fitness testing battery, comprising maximal aerobic capacity ($\dot{\text{V}}{\text{O}}_{2\max }$), lactate threshold, anaerobic power, body composition (dual-energy X-ray absorptiometry), muscular strength (3 repetition maximum (3RM) bench and leg press) and muscular endurance (maximum curl ups and push ups) under controlled laboratory conditions. On a separate occasion, ARFF completed timed work-related tasks including a hose drag, dummy drag, Stihl saw hold, stair climb and simulated ARFF emergency protocol.ResultsAll participants finished the simulated ARFF emergency protocol under the criterion time (5 min 50 s); the average completion time was 4 min and 31 s. Performance time on the simulated ARFF emergency protocol was inversely correlated to $\dot{\text{V}}{\text{O}}_{2\max }$ (r = −0.514; p < 0.001), anaerobic step test performance (r = −0.549; p < 0.001), height (r = −0.325; p = 0.038) and lean mass (r = −0.429; p = 0.005). Higher fat mass (r = 0.318; p = 0.043) and % body fat (r = 0.481; p = 0.001) were associated with slower performance time. Muscular strength, muscular endurance and flexibility were not related to performance on the simulated ARFF emergency protocol.ConclusionsAerobic and anaerobic capacities, as well as body composition are the strongest predictors of simulated ARFF emergency protocol performance. This study highlights the importance of aerobic and anaerobic fitness, compared to muscular strength or muscular endurance, for ARFF job-specific performance, employment and training.     

A review and clinical summary of vitamin D in regard to bone health and athletic performance

Football helmets have become safer in the past few years, but liability claims have increased. Manufacturers and school districts are considering solutions such as new designs, insurance coverage, and education programs.     

Effect of induced alkalosis on performance during a field-simulated BMX cycling competition

Objectives

The aim of the present study was to test the effect of sodium bicarbonate (NaHCO₃^?) ingestion on performance during a simulated competition on a Bicycle Motocross (BMX) track.

The effects of a combined static-dynamic stretching protocol on athletic performance in elite Gaelic footballers: A randomised controlled crossover trial

ObjectivesTo determine the effect of three different static-dynamic stretching protocols on sprint and jump performance in Gaelic footballers.DesignDouble-blind, controlled, crossover trial.SettingSports Institute research environment.ParticipantsSeventeen male elite level Gaelic footballers, aged 18–30 years, completed three stretching protocols.Main Outcome MeasuresAthletic performance was measured by countermovement jump height and power, and timed 10 m, 20 m, and 40 m sprints.ResultsStatic stretching reduced sprint speed by 1.1% over 40 m and 1.0% over 20 m. Static stretching also reduced countermovement jump height by 10.6% and jump power by 6.4%. When static stretching was followed by dynamic stretching, sprint speed improved by 1.0% over 20 m and 0.7% over 40 m (p < 0.05). The static - dynamic stretching protocol also improved countermovement jump height by 8.7% (p < 0.01) and power by 6.7% (p < 0.01).ConclusionsStatic stretching reduces sprint speed and jump performance. Static stretching should be followed by dynamic stretching during warm-up to nullify any performance deficits caused by static stretching.     

The effect of mental fatigue on the performance of Australian football specific skills amongst amateur athletes

ObjectivesThis study investigated the effects of induced mental fatigue on the performance of Australian football (AF) specific skills amongst amateur AF players.DesignRandomised cross over trial.MethodsTwenty-five amateur AF players performed a series of standardised tests from the Australian Football League (AFL) Draft Combine after completing a 30-min Stroop test (mental fatigue condition) or 30-min control condition. The AFL Draft Combine tests included the standing vertical jump test, running vertical jump test, agility test, 20 m sprint, Matthew Lloyd clean hands test, Brad Johnson goal kicking test and a Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) test.ResultsThe Stroop test score decreased during the Stroop test (first five trials: mean = 84.7, SD = 3.5; last five trials: mean = 82.2, SD = 5.0, p = 0.03). The Yo-Yo IR1 test (mental fatigue: median = 920 m, IQR = 400; control: median = 1040 m, IQR = 760; p = 0.03) and Brad Johnson goalkicking test (mental fatigue: median = 19.0, IQR = 5.0; control: median = 25.0, IQR = 10.0, p = 0.048) were negatively affected by mental fatigue. No other Draft Combine tests demonstrated a negative affect from mental fatigue.ConclusionsMental fatigue had a detrimental influence on the performance of AF specific skills. The findings may have implications for AF players who are required to sustain attention and concentration for prolonged periods before and during matches.     

A randomized trial of traditional and golf-specific resistance training in amateur female golfers: Benefits beyond golf performance

ObjectiveCompare golf-specific resistance training (GSRT) with traditional resistance training (TRAD) with regard to golf performance and other outcome measures.DesignRandomized controlled study.SettingOutpatient gym.Participants45 female golfers were randomized into TRAD or GSRT, both of which targeted muscles active during the golf swing. Participants performed supervised training 3d^.wk⁻¹ for 10 weeks.Outcome MeasuresGolf performance, bone density, body composition, and physical performance tests.Results29 individuals (58.1 ± 2.1y; 15 TRAD, 14 GSRT) completed training. Completers were older (p = 0.048) and played golf more frequently than non-completers (p = 0.002), but were not otherwise different. Training decreased whole body fat mass (p = 0.013) and visceral fat mass (p = 0.033) across groups, but did not influence lean mass (p = 0.283) or bone mineral density (p = 0.205). Training increased driver speed (p = 0.001), driver distance (p = 0.020), and 7I distance (p < 0.001), but not 7I speed (p = 0.160), but no group or interaction effects were present. Training increased all physical performance tests (p ≤ 0.005) regardless of group, but the seated medicine ball throw was most related to baseline driver speed (r² = 0.384), and also most responsive to training (r² = 0.250).Conclusion10 weeks of supervised TRAD and GSRT provided similar improvements in body composition, golf performance, and physical performance in amateur female golfers.     

The effect of a physical activity education programme on physical activity, fitness, quality of life and attitudes to exercise in obese females

Obesity has reached epidemic proportions worldwide. Decline in physical activity has occurred simultaneously or before the increase in obesity. The aim of this pilot study was to investigate the effect of a physical activity group-based education programme delivered by a Physiotherapist on weight, physical activity, cardiovascular fitness, quality of life and attitudes to exercise in obese females. A sample of 18 obese Irish females (mean age 37.6 years, mean weight 117.9kg), took part in this study. The participants attended four physical activity education sessions in groups of 6-8, 1 month apart. Outcome measures were Cardiorespiratory fitness (CRF) measured by the Incremental Shuttle Walk test (ISWT) International Physical Activity Questionnaire-Short Form (IPAQ-Short) Impact of Weight on Quality of Life Questionnaire-Short Form (IWQOL-Lite), and a questionnaire adapted from the EU survey on Consumer Attitudes to Physical Activity. There were no significant decreases in participants' weight (p=0.444) and there were no significant improvements in IPAQ (p=0.496) and IWQOL-Lite scores (p=0.337). There were significant improvements in CRF (p<0.0002). Attitudes towards exercise improved as shown by decreased barriers to exercise, i.e. decreased shyness (17%) and increased energy (22%) and increased enjoyment (22%). A group education programme focusing on physical activity alone demonstrated a significant increase in CRF (ISWT) and had a positive influence on attitudes to exercise. Longer duration interventions may allow participants to make the necessary lifestyle changes to achieve weight loss.