Background:Attrition rate in new army recruits is higher than in incumbent troops.In the current study,we identified the risk factors for attrition due to injuries and physical fitness failure in recruit training.A va...Background:Attrition rate in new army recruits is higher than in incumbent troops.In the current study,we identified the risk factors for attrition due to injuries and physical fitness failure in recruit training.A variety of predictive models were attempted.Methods:This retrospective cohort included 19,769 Army soldiers of the Australian Defence Force receiving recruit training during a period from 2006 to 2011.Among them,7692 reserve soldiers received a 28-day training course,and the remaining 12,077 full-time soldiers received an 80-day training course.Retrieved data included anthropometric measures,course-specific variables,injury,and physical fitness failure.Multivariate regression was used to develop a variety of models to predict the rate of attrition due to injuries and physical fitness failure.The area under the receiver operating characteristic curve was used to compare the performance of the models.Results:In the overall analysis that included both the 28-day and 80-day courses,the incidence of injury of any type was 27.8%.The 80-day course had a higher rate of injury if calculated per course(34.3%vs.17.6%in the 28-day course),but lower number of injuries per person-year(1.56 vs.2.29).Fitness test failure rate was significantly higher in the 28-day course(30.0%vs.12.1%).The overall attrition rate was 5.2%and 5.0%in the 28-day and 80-day courses,respectively.Stress fracture was common in the 80-day course(n=44)and rare in the 28-day course(n=1).The areas under the receiver operating characteristic curves for the course-specific predictive models were relatively low(ranging from 0.51 to 0.69),consistent with"failed"to"poor"predictive accuracy.The course-combined models performed somewhat better than the course-specific models,with two models having AUC of 0.70 and 0.78,which are considered"fair"predictive accuracy.Conclusion:Attrition rate was similar between 28-day and 80-day courses.In comparison to the 80-day full course,the 28-day course had a lower rate of injury but a higher number of injuries per person-year and of fitness test failure.These findings suggest fitness level at the commencement of training is a critically important factor to consider when designing the course curriculum,particularly short courses.展开更多
This study examined the effects of combined anti-inflammatories and specific nutrients on recovery from resistance exercises. Trained individuals （n = 14） performed three sets to failure at a 8-12 repetition maximum...This study examined the effects of combined anti-inflammatories and specific nutrients on recovery from resistance exercises. Trained individuals （n = 14） performed three sets to failure at a 8-12 repetition maximum load for six resistance exercises, then repeated this workout after 24 h. Participants consumed a protein-carbohydrate shake （330 ml; 20 g protein; 45 g carbohydrate）, vitamin C （1000 mg）, vitamin E （400 I.U.） and ibuprofen （100 mg） immediately after the initial workout. Another dose of vitamin C and ibuprofen were respectively consumed 1 h or 30 min before the second workout. On another occasion （counterbalanced） a placebo of flavored water, two imitation vitamins （gummy candies）, and two replica ibuprofen （sugar pills） were consumed. A 10-cm visual analog scale （VAS） assessed pain, ratings of perceived exertion （RPE）, and ratings of perceived recovery （RPR）. Treatment enhanced performance-based recovery （repetitions after 24h） for the chest press （P 〈 0.010） and latissimus pull-down （P 〈 0.010）. Within-condition comparisons revealed performance decrements （P 〈 0.050） after 24 h for 83% of the exercises under placebo, compared to 50% of exercises under treatment. Treatment enhanced RPR （P = 0.038） compared to placebo, but had no significant effects on residual （P = 0.215） or exercise （P 〉 0.050） pain. RPE was lower under the treatment for the chest press （P = 0.016） and overall workout （P = 0.038） on Day 1, but similar among all exercises on Day 2 （P 〉 0.050）. This treatment may promote increases in performance without increasing pain or RPE.展开更多
Purpose To determine the relationship between metabolic fitness test scores and performance in police occupational tasks.Methods Retrospective data from 106 law enforcement officers who completed two metabolic fitness...Purpose To determine the relationship between metabolic fitness test scores and performance in police occupational tasks.Methods Retrospective data from 106 law enforcement officers who completed two metabolic fitness assessments[anaerobic:a 20-m (10-m and 20-m splits) sprint,aerobic:20 m Multi-Stage Fitness Test (20 m-MSFT)]and three routine occupational tasks[1.22 m Fence jump (FJ),8.5 m Victim Drag (VD with 102.3 kg) and "Get-up" (GU)]were collected.A Person's cor-relation coefficient and a standard multiple regression were used to assess the relationship between and predictive ability of,respectively,the fitness tests scores and performance on occupational tasks.Results There was a significant positive correlation between the 10-m sprint scores and FJ (r=0.524,P<0.001),VD(r =0.528,P < 0.001) and GU (r=0.486,P < 0.001).Similarly,the 20-m sprint scores were significantly and moderately correlated with FJ (r=0.573,P < 0.001),VD (r=0.603,P < 0.001) and GU (r=0.533,P < 0.001).These anaerobic tests' scores predicted approximately 40% of the performance in the occupational tasks analysed.The MSFT fitness assessment had a small,albeit significant negative correlation with the three tasks:FJ (r=-0.360,P< 0.001),VD (r=-0.266,P=0.012)and GU (r=-0.375,P< 0.001).Conclusion High levels of metabolic fitness correlated with faster performance in police officer occupational tasks,particu-larly ones of an anaerobic nature (i.e.the maximal sprint tests).In addition to typical aerobic fitness conditioning,anaerobic fitness conditioning could be vital for optimal performance in physically demanding tasks required of police officer.展开更多
The original version of this article,published on August 7,2020,contained a mistake.The affiliations were incorrect.The correct affiliations of the authors are given below.
文摘Background:Attrition rate in new army recruits is higher than in incumbent troops.In the current study,we identified the risk factors for attrition due to injuries and physical fitness failure in recruit training.A variety of predictive models were attempted.Methods:This retrospective cohort included 19,769 Army soldiers of the Australian Defence Force receiving recruit training during a period from 2006 to 2011.Among them,7692 reserve soldiers received a 28-day training course,and the remaining 12,077 full-time soldiers received an 80-day training course.Retrieved data included anthropometric measures,course-specific variables,injury,and physical fitness failure.Multivariate regression was used to develop a variety of models to predict the rate of attrition due to injuries and physical fitness failure.The area under the receiver operating characteristic curve was used to compare the performance of the models.Results:In the overall analysis that included both the 28-day and 80-day courses,the incidence of injury of any type was 27.8%.The 80-day course had a higher rate of injury if calculated per course(34.3%vs.17.6%in the 28-day course),but lower number of injuries per person-year(1.56 vs.2.29).Fitness test failure rate was significantly higher in the 28-day course(30.0%vs.12.1%).The overall attrition rate was 5.2%and 5.0%in the 28-day and 80-day courses,respectively.Stress fracture was common in the 80-day course(n=44)and rare in the 28-day course(n=1).The areas under the receiver operating characteristic curves for the course-specific predictive models were relatively low(ranging from 0.51 to 0.69),consistent with"failed"to"poor"predictive accuracy.The course-combined models performed somewhat better than the course-specific models,with two models having AUC of 0.70 and 0.78,which are considered"fair"predictive accuracy.Conclusion:Attrition rate was similar between 28-day and 80-day courses.In comparison to the 80-day full course,the 28-day course had a lower rate of injury but a higher number of injuries per person-year and of fitness test failure.These findings suggest fitness level at the commencement of training is a critically important factor to consider when designing the course curriculum,particularly short courses.
文摘This study examined the effects of combined anti-inflammatories and specific nutrients on recovery from resistance exercises. Trained individuals （n = 14） performed three sets to failure at a 8-12 repetition maximum load for six resistance exercises, then repeated this workout after 24 h. Participants consumed a protein-carbohydrate shake （330 ml; 20 g protein; 45 g carbohydrate）, vitamin C （1000 mg）, vitamin E （400 I.U.） and ibuprofen （100 mg） immediately after the initial workout. Another dose of vitamin C and ibuprofen were respectively consumed 1 h or 30 min before the second workout. On another occasion （counterbalanced） a placebo of flavored water, two imitation vitamins （gummy candies）, and two replica ibuprofen （sugar pills） were consumed. A 10-cm visual analog scale （VAS） assessed pain, ratings of perceived exertion （RPE）, and ratings of perceived recovery （RPR）. Treatment enhanced performance-based recovery （repetitions after 24h） for the chest press （P 〈 0.010） and latissimus pull-down （P 〈 0.010）. Within-condition comparisons revealed performance decrements （P 〈 0.050） after 24 h for 83% of the exercises under placebo, compared to 50% of exercises under treatment. Treatment enhanced RPR （P = 0.038） compared to placebo, but had no significant effects on residual （P = 0.215） or exercise （P 〉 0.050） pain. RPE was lower under the treatment for the chest press （P = 0.016） and overall workout （P = 0.038） on Day 1, but similar among all exercises on Day 2 （P 〉 0.050）. This treatment may promote increases in performance without increasing pain or RPE.
文摘Purpose To determine the relationship between metabolic fitness test scores and performance in police occupational tasks.Methods Retrospective data from 106 law enforcement officers who completed two metabolic fitness assessments[anaerobic:a 20-m (10-m and 20-m splits) sprint,aerobic:20 m Multi-Stage Fitness Test (20 m-MSFT)]and three routine occupational tasks[1.22 m Fence jump (FJ),8.5 m Victim Drag (VD with 102.3 kg) and "Get-up" (GU)]were collected.A Person's cor-relation coefficient and a standard multiple regression were used to assess the relationship between and predictive ability of,respectively,the fitness tests scores and performance on occupational tasks.Results There was a significant positive correlation between the 10-m sprint scores and FJ (r=0.524,P<0.001),VD(r =0.528,P < 0.001) and GU (r=0.486,P < 0.001).Similarly,the 20-m sprint scores were significantly and moderately correlated with FJ (r=0.573,P < 0.001),VD (r=0.603,P < 0.001) and GU (r=0.533,P < 0.001).These anaerobic tests' scores predicted approximately 40% of the performance in the occupational tasks analysed.The MSFT fitness assessment had a small,albeit significant negative correlation with the three tasks:FJ (r=-0.360,P< 0.001),VD (r=-0.266,P=0.012)and GU (r=-0.375,P< 0.001).Conclusion High levels of metabolic fitness correlated with faster performance in police officer occupational tasks,particu-larly ones of an anaerobic nature (i.e.the maximal sprint tests).In addition to typical aerobic fitness conditioning,anaerobic fitness conditioning could be vital for optimal performance in physically demanding tasks required of police officer.
文摘The original version of this article,published on August 7,2020,contained a mistake.The affiliations were incorrect.The correct affiliations of the authors are given below.
