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Alemany, JA, Pierce, JR, Bornstein, DB, Grier, TL, Jones, BH, and Glover, SH. Comprehensive physical activity assessment during U.S. Army Basic Combat Training. J Strength Cond Res XX(X): 000-000, 2021-Physical activity (PA) volume, intensity, and qualitative contextual information regarding activity type and loads carried are limited during U.S. Army Basic Combat Training (BCT). The purpose of this study was to characterize daily (05:00-20:00 hours) PA during BCT using a comprehensive approach. During 2 10-week BCT cycles (n = 40 trainees per cycle), pedometers, accelerometers, and direct observation were used to estimate daily step count, PA volume, and intensity. Physical activity intensity was categorized by metabolic equivalents (METs) such as "sedentary" (1-2 METs), "light" (2-3 METs), "moderate" (3-6 METs), or "vigorous" (≥6 METs). Daily PA data were analyzed longitudinally using linear mixed models, with significance set at p ≤ 0.05. The mean daily step count was 13,459 ± 4,376 steps, and the mean daily accelerometer-assessed PA volume and intensity were as follows: sedentary: 505 ± 98 minutes, light: 190 ± 78 minutes, moderate: 168 ± 51 minutes, and vigorous: 14 ± 14 minutes, with no differences between cycles for all measures (p > 0.50). Cumulative time on feet (∼50%) and sitting (20-25%) accounted for most daily activity types during both cycles. Trainees, on average, carried between 3 and 9 kg, and ≥9 kg, for 60% and 10% of the monitored day, respectively. Basic Combat Training's physical demands are high, where trainees achieved 1.7 to 2.7 times greater daily ambulation and 6 times the recommended weekly moderate-to-vigorous PA compared with civilian counterparts and performed weight-bearing load carriage for nearly half of the day. Basic Combat Training-associated PA may increase injury risk among trainees unaccustomed to arduous PA and exercise. Implementing national PA policies to improve physical fitness and facilitate acclimatization to BCT's high physical demands could reduce public health burdens and military nonreadiness.

Objectives To determine the age- and sex-specific differences of physical fitness performances and Body Mass Index (BMI) in basic training and the operational Army. Design Cross-sectional Study. Methods This secondary analysis utilizes retrospective surveys of U.S. Army Soldiers in Basic Combat Training (BCT) and operational units to compare physical performances between men and women as measured by the Army Physical Readiness Test (APFT). An ANOVA was used to compare mean differences in APFT results and BMI within sex-specific populations. A post hoc Tukey test identified specific mean differences. Adjusting for age, an ANCOVA was used to compare sex and occupation (infantry and non-infantry) differences in APFT results. Results Surveyed populations consisted of 2216 BCT Soldiers (1573 men and 643 women) and 5515 Operational Soldiers (4987 men and 528 women). Male and female operational Soldiers had greater muscular performance (79%–125% higher APFT push-ups, 66%–85% higher APFT sit-ups) and cardiorespiratory performance (22%–24% faster APFT 2-mile run times) than BCT Soldiers. Male BCT and operational Soldiers outperform their female counterparts on tests of muscular and cardiorespiratory endurance. Sex differences in physical performances attenuated among female Soldiers in operational units compared to BCT. Among male operational Soldiers, infantry Soldiers exhibited greater cardiorespiratory and muscular performance than non-infantry Soldiers. Higher BMI was associated with higher age groups, except for female BCT Soldiers. Conclusions Gaps in cardiorespiratory and muscular performances between men and women should be addressed through targeted physical training programs that aim to minimize physiological differences.

Objectives The Functional Movement Screen (FMS™) has been used as a screening tool to determine musculoskeletal injury risk using composite scores based on movement quality and/or pain. However, no direct comparisons between movement quality and pain have been quantified. Design Retrospective injury data analysis. Methods Male Soldiers (n = 2154, 25.0 ± 1.3 years; 26.2 ± .7 kg/m 2 ) completed the FMS (scored from 0 points (pain) to 3 points (no pain and perfect movement quality)) with injury data over the following six months. The FMS is seven movements. Injury data were collected six months after FMS completion. Sensitivity, specificity, receiver operator characteristics and positive and negative predictive values were calculated for pain occurrence and low (≤14 points) composite score. Risk, risk ratios (RR) and 95% confidence intervals were calculated for injury risk. Results Pain was associated with slightly higher injury risk (RR = 1.62) than a composite score of ≤14 points (RR = 1.58). When comparing injury risk between those who scored a 1, 2 or 3 on each individual movement, no differences were found (except deep squat). However, Soldiers who experienced pain on any movement had a greater injury risk than those who scored 3 points for that movement (p Conclusions Pain occurrence may be a stronger indicator of injury risk than a low composite score and provides a simpler method of evaluating injury risk compared to the full FMS.

Objective The purpose of this study was to: 1) evaluate differential responses of the IGF-I system to either a calisthenic- or resistance exercise-based program and 2) determine if this chronic training altered the IGF-I system during an acute resistance exercise protocol. Design Thirty-two volunteers were randomly assigned into a resistance exercise-based training (RT) group ( n =15, 27±5y, 174±6cm, 81±12kg) or a calisthenic-based training group (CT) ( n =17, 29±5y, 179±8cm, 85±10kg) and all underwent 8weeks of exercise training (1.5h/d, 5d/wk). Basal blood was sampled pre- (Week 0), mid- (Week 4) and post-training (Week 8) and assayed for IGF-I system analytes. An acute resistance exercise protocol (AREP) was conducted preand post-training consisting of 6 sets of 10 repetitions in the squat with two minutes of rest in between sets and the IGF-I system analytes measured. A repeated measures ANOVA ( p ≤0.05) was used for statistical analysis. Results No interaction or within-subject effects were observed for basal total IGF-I, free IGF-I, or IGFBP-1. IGFBP-2 (pre; 578.6±295.7 p =0.008) and Acid Labile Subunit (ALS) changed over the exercise training (pre-; 16.2±1.3=mid-; 17.6±1.8>post-training; 14.3±1.9μg/mL; p =0.01). An interaction was observed for the RT group as IGFBP-3 increased from pre to mid (3462.4±216.4 vs. 3962.2±227.9ng/mL), but was not significant at the post-training time point (3770.3±228.7ng/mL). AREP caused all analytes except free IGF-I (40% decrease) to increase (17–27%; p =0.001) during exercise, returning to baseline concentration into recovery. Conclusion Post-training, bioavailable IGF-I recovered more rapidly post-exercise. 8wks of chronic physical training resulted in increased basal IGFBP-2 and IGFBP-3, decreased ALS, increased pre-AREP free IGF-I and a more rapid free IGF-I recovery post-AREP. While total IGF-I was insensitive to chronic physical training, changes were observed with circulating IGFBPs and bioavailable IGF-I. To glean the most robust information on the effects of exercise training, studies must move beyond relying solely on total IGF-I measures and should consider IGFBPs and bioavailable IGF-I as these components of the circulating IGF-I system are essential determinants of IGF-I physiological action.