Evaluation of Nutrition and Performance Parameters in Division 1 Collegiate Athletes.

BACKGROUND: Testing and evaluating athletes is necessary and should include performance, body composition, and nutrition. The purpose of this study was to report assessments of dietary intake, V˙O2max, and body composition in D1 collegiate athletes and examine relationships between these assessments. METHODS: Dietary intake was assessed with 3-day recalls and compared to recommendations, and body composition was assessed via bioelectrical impedance analysis (BIA) (n = 48). V˙O2max was evaluated using a graded exercise test (GXT) with a verification bout (n = 35). Reliability between "true" V˙O2max and verification was determined. Correlations and regressions were performed. RESULTS: Energy, carbohydrate, and micronutrient intake was lower than recommendations. Mean V˙O2max was 47.3 and 47.4 mL·kg-1·min-1 for GXT and verification, respectively. While correlations were apparent among dietary intake, V˙O2max, and body composition, percent fat-free mass (%FFM) predicted 36% of V˙O2max. CONCLUSIONS: Collegiate athletes are not meeting energy and carbohydrate recommendations and exceed fat recommendations. Vitamin D and magnesium were low in all sports, and iron and calcium were low in females. V˙O2max ranged from 35.6 to 63.0 mL·kg-1·min-1, with females below average and males meeting typical values for their designated sport. Assessing D1 athletes can provide guidance for sports dietitians, coaches, and strength and conditioning specialists to track and monitor nutrition in athletes.

Contributions from incumbent police officer's physical activity and body composition to occupational assessment performance.

Introduction: Police officers must perform various tasks in unpredictable work environments and potentially volatile situations. This study aimed to determine if cardiovascular fitness, body composition, and physical activity levels could predict performance in a Midwest Police Department's Physical Readiness Assessment (PRA). Methods: Researchers collected data from thirty incumbent police officers (33.9 ± 8.3 years, female = 5). Anthropometric data included height, body mass, body fat percentage (BF%), fat-free mass (FFM), and maximal hand grip strength. The police officers also completed a physical activity rating (PA-R) scale to estimate maximal oxygen consumption (V˙O2max) and the International Physical Activity Questionnaire (IPAQ). Police officers then conducted their department's PRA. Stepwise linear regression analyses were used to determine the relationship between predictor variables and PRA performance. Pearson's product-moment correlations investigated relationships between anthropometric, physical fitness, and physical activity variables and PRA performance using SPSS (v.28). The significance level was set at p < 0.05. Results: Descriptive data for the sample includes BF%: 27.85 ± 7.57%, FFM: 65.73 ± 10.72 kg, hand grip strength: 55.51 ± 11.07 kg, weekday sedentary time (WST): 328 ± 28.26 min, weekend day sedentary time (WDST): 310 ± 28.92 min, daily moderate-to-vigorous physical activity (MVPA): 29.02 ± 39.41 min, PRA: 273.6 ± 51.4 s and estimated V˙O2max: 43.26 ± 6.35 mL kg-1 min-1. The stepwise regression analyses indicated that BF% was predictive of PRA time (R2 = 0.32, p < 0.01); estimated V˙O2max predictive of PRA time (R2 = 0.45, p < 0.001). There were significant correlations between BF % and PRA time (r = 0.57, p < 0.001), PA-R and MVPA (r = 0.71, p < 0.001), %BF % and WDST (r = -0.606, p < 0.001), hand grip and FFM (r = 0.602, p < 0.001) and PA-R and PRA time (r = -0.36, p < 0.05). Discussion: The results of this exploratory study highlight that higher estimated V˙O2max and lower BF% were the best predictors for faster PRA completion times, accounting for 45% and 32% of the variance, respectively. The findings of this study support the need for wellness and fitness initiatives in law enforcement agencies focused on increasing cardiovascular fitness and physical activity while decreasing BF% to ensure optimal performance in policing and overall health.

Comparable Acute Metabolic Responses when Walking with Blood Flow Restriction and Walking with Load Carriage: Implication for Tactical Professionals.

The current study aimed to investigate exercise with blood flow restriction (BFR) as a low-intensity conditioning strategy in tactical professionals with load carriage. During the low-intensity exercise, researchers examined the acute metabolic responses from low-intensity BFR walking, walking with load carriage, and walking with BFR and load carriage. Twelve healthy adult males (age = 21.8 ± 1.5 yrs, height = 181.3 ± 7.2 cm, body mass = 84.4 ± 11.1 kg and BMI = 25.6 ± 2.6 kg·m2) completed five bouts of 3-min treadmill walking at 4.8 km·h-1 with 1-min rest interval under three different conditions: 1) blood flow restriction (BFR), 2) loaded with 15% of body mass (LOAD) and 3) loaded with 15% of body mass with blood flow restriction (BFR-LOAD). Oxygen consumption (V̇O2), heart rate, and local muscle oxygen saturation was measured during the exercise bouts. V̇O2 increased by 7% during the BFR- LOAD (p = 0.001) compared with BFR or LOAD alone. There were no differences in V̇O2 between BFR and LOAD (p = 0.202). BFR-LOAD showed significantly lower (-9%) muscle oxygen saturation (p = 0.044) and deoxygenated hemoglobin (p = 0.047) compared to LOAD. Low-intensity walking with the addition of BFR shares acute metabolic characteristics similar to walking with a load. These characteristics suggest there is potential for the use of BFR to increase exercise intensity for individuals training with load carriage.

Comparable Levels of Objectively Measured Physical Activity and Cardiorespiratory Fitness in Firefighters From Two Midwest Fire Departments.

OBJECTIVE: The aim of the study is to objectively assess if firefighters are meeting the National Fire Protection Association (NFPA) cardiorespiratory fitness (CRF) and American College of Sports Medicine/American Heart Association physical activity (PA) guidelines. METHODS: Two independent fire departments from the Midwest participated in the study. Firefighters wore an accelerometer to track PA and associated intensities. In addition, firefighters completed a stage-graded exercise test TO determine their maximal oxygen uptake (V˙O 2max ). RESULTS: A total of 43 career firefighters completed the study (fire department 1 [FD1]: n = 29, FD2: n = 14). Almost half (44.8% FD1 and 42.9% FD2) met the NFPA CRF guidelines. Compared with the American College of Sports Medicine PA Guidelines of 30 min/d of moderate-to-vigorous PA, more than half of FD2 (57.1%) met the recommended amount of PA, whereas FD1 had less than half (48.3%). CONCLUSIONS: These data demonstrate the need to improve firefighters' PA levels, CRF, and overall health.

Customized Occupational-Specific Graded Exercise Test for Structural Firefighters: An Update.

OBJECTIVE: The aim of the study is to validate a customized V˙O 2max Graded Exercise Test (GXT) protocol specifically to accommodate firefighters with different cardiovascular fitness levels. METHODS: Career male firefighters (N = 15) completed 3 customized GXTs on a treadmill: 1 in athletic clothes and 2 in their bunker gear to determine maximal oxygen uptake (V˙O 2max ). RESULTS: The on-duty task protocol was reliable, V˙O 2max values of 40.2 ± 4.6 mL·kg·min -1 and 40.3 ± 5.3 mL·kg·min -1 between trials yielded an interclass correlation of 0.911 with a typical error of 1.48 mL·kg·min -1 and a coefficient of variation of 4.0%. The validity analysis indicated consistent maximal V˙O 2 values for the GXTs yielding mean interclass correlation of 0.94 with typical error of 1.16 mL·kg·min -1 and a coefficient of variation of 2.9%. CONCLUSIONS: The customized GXT for structural firefighters has shown to be a reliable, valid, and applicable method of testing cardiovascular fitness in firefighters.

Moderate to vigorous physical activity, leucine, and protein intake contributions to muscle health in middle age.

Objective: Identify contributors to differences in the muscle size and strength of sedentary and active young and middle-aged adults. Methods: This cross-sectional study included 98 participants aged 20-65 years. Participants were categorized based on age and self-reported physical activity (PA) habits. Participants completed a strength assessment of knee extensors (KEPT), knee flexors (KFPT), plantar flexors (PFPT), and dorsiflexors (DFPT), a 3-day dietary intake log, 7-day accelerometry, and a magnetic resonance imaging (MRI) scan for muscle cross-sectional area analysis of the right quadriceps (CSAq). Results: There were significant age and activity-related group effects for relative protein intake (p<0.001), relative energy intake (p=0.04), KEPT (p=0.01), CSAq (p=0.002), PFPT (p=0.004) and DFPT (p=0.003). Moderate, moderate-to-vigorous, and vigorous PA were positively associated with CSAq (R2=0.69- 0.71; p<0.05), KEPT (R2=0.61-0.63; p<0.05), and PFPT (R2=0.31-0.36; p<0.05). Relative protein intake and daily leucine intake were significantly and positively associated with CSAq (R2=0.70 and 0.67 respectively; p<0.05), KEPT (R2=0.62 and 0.65 respectively; p<0.05), and PFPT (R2=0.29 and 0.28 respectively; p<0.05). Conclusion: Muscle size and strength were lower in middle age relative to younger age, but increased PA, protein intake, and leucine intake was associated with the preservation of muscle size and strength in larger muscle groups of the lower body.

Optimization of the Critical Speed Concept for Tactical Professionals: A Brief Review.

Tactical professionals often depend on their physical ability and fitness to perform and complete occupational tasks to successfully provide public services or survive on the battlefield. Critical speed (CS), or maximal aerobic steady-state, is a purported measure that predicts performance, prescribes exercise, and detects training adaptions with application to tactical professionals. The CS concept has the versatility to adapt to training with load carriage as an integrated bioenergetic system approach for assessment. The aims of this review are to: (1) provide an overview of tactical populations and the CS concept; (2) describe the different methods and equipment used in CS testing; (3) review the literature on CS associated with tactical occupational tasks; and (4) demonstrate the use of CS-derived exercise prescriptions for tactical populations.

Measures Derived from Panoramic Ultrasonography and Animal-Based Protein Intake Are Related to Muscular Performance in Middle-Aged Adults.

Ultrasonography advantageously measures skeletal muscle size and quality, but some muscles may be too large to capture with standardized brightness mode (B-mode) imaging. Panoramic ultrasonography can capture more complete images and may more accurately measure muscle size. We investigated measurements made using panoramic compared to B-mode ultrasonography images of the rectus femoris with muscular performance. Concurrently, protein intake plays an important role in preventing sarcopenia; therefore, we also sought to investigate the association between animal-based protein intake (ABPI) and muscular performance. Ninety-one middle-aged adults were recruited. Muscle cross-sectional area (CSA) and thickness were obtained using B-mode and panoramic ultrasound and analyzed with Image J software. Muscular performance was assessed using isokinetic dynamometry, a 30-s chair test, and handgrip strength. Three-day food diaries estimated dietary intakes. Linear regression models determined relationships between measures from ultrasonography and muscular performance. Mixed linear models were used to evaluate the association between ABPI and muscular performance. Muscle CSA from panoramic ultrasonography and ABPI were positively associated with lower-body strength (ß ± S.E.; CSA, 42.622 ± 20.024, p = 0.005; ABPI, 65.874 ± 19.855, p = 0.001), lower-body endurance (ß ± S.E.; CSA, 595 ± 200.221, p = 0.001; ABPI, 549.944 ± 232.478, p = 0.020), and handgrip strength (ß ± S.E.; CSA, 6.966 ± 3.328, p = 0.004; ABPI, 0.349 ± 0.171, p = 0.045). Panoramic ultrasound shows promise as a method for assessing sarcopenia. ABPI is related to better muscular performance.

Increased velocity at VO2max and load carriage performance in army ROTC cadets: prescription using the critical velocity concept.

The purpose of this study was to evaluate the effects of using the critical velocity (CV) concept to prescribe two separate high-intensity interval training (HIT) exercise programs aimed at enhancing CV and load carriage performance. 20 young adult participants (male = 15, female = 5) underwent a 4-week training period where they exercised 2 d wk-1. Participants were randomly assigned into two groups: (1) HIT or (2) Load Carriage-HIT (LCHIT). Pre- and post-training assessments included running 3-minute All-Out Test (3MT) to determine critical velocity (CV) and distance prime (D') and two load carriage tasks (400 and 3200 m). There were significant increases in CV (p = 0.005) and velocity at V˙ O2max (vV˙ O2max) (p = 0.037) among the sample but not between training groups. Improvements were observed in 3200 m load carriage performance time (p < 0.001) with a 9.8 and 5.4% decrease in the LCHIT and HIT groups, respectively. Practitioner summary: Critical velocity has shown efficacy as a marker for performance in tactical populations. With the addition of load carriage, there is a reduction in the individual's CV. The CV-concept-prescribed exercises (HIT and LCHIT) 2 days per week for 4 weeks showed improvements in CV, vV˙ O2max and load carriage performance. The use of the CV concept provides a method to prescribe HIT to increase running and load carriage performances in tactical populations.

Firefighters Are More Physically Active On-Duty Compared to Off-Duty.

Physical inactivity, coupled with increasing obesity levels, in firefighters plays a key role in aggregated cardiovascular events. The purpose of this study was to investigate device-measured physical activity (PA) for firefighters while on- and off-duty to have a clearer understanding of their overall PA level. METHODS: Twenty-nine career firefighters participated in this non-experimental, within-subjects study by wearing an accelerometer to assess PA intensities and step-count. Obesity was classified using body mass index (BMI). Dependent t-tests were used to examine mean differences in PA intensities when on- and off-duty. Pearson product-moment correlations were used to assess the association between PA intensities when on and off-duty. RESULTS: According to the World Health Organization BMI categorizations, 20 firefighters were overweight, 9 were obese, and, thus, none were normal weight. Only light PA (LPA) was statistically significant (p = 0.026) for on- and off-duty days with a small-to-medium effect size (d = 0.47), meaning that on average, firefighters performed more minutes of LPA when on-duty compared to off. There was a significant difference between on- (9060.2 ± 2636.4) and off-duty (7495.3 ± 2835.8) daily step counts (p = 0.011). CONCLUSION: As the results demonstrate, there is a dire need for increased PA levels in firefighters while on- and off-duty.

Firefighters' Physical Activity and Waist Circumference as Predictors of VO2max.

OBJECTIVE: To examine associations among objectively measured physical activity (PA), body mass index (BMI), waist circumference (WC), and cardiorespiratory fitness (CRF) in firefighters. METHODS: Career firefighters (n = 29; male = 100%) wore accelerometers to assess PA. BMI and WC classified obesity. Each participant completed a stage-graded exercise test to determine maximal oxygen uptake ((Equation is included in full-text article.)). RESULTS: Two linear regression models were used to investigate whether PA intensities, step count, BMI, or WC were predictive of "true" (Equation is included in full-text article.). Vigorous physical activity (VPA) was predictive of "true" (Equation is included in full-text article.)(F[1,27] = 7.89, R = 0.23, P < 0.01). Additionally, when BMI and WC were added, only WC was predictive of "true" (Equation is included in full-text article.)(F[1,27] = 11.76, R = 0.30, P < 0.01). CONCLUSION: Fire departments should be cognizent of ways to increase PA levels, decrease excess weight gain, and maintain CRF to adequately perform job-specific tasks.

Simulated Casualty Evacuation Performance Is Augmented by Deadlift Peak Force.

INTRODUCTION: The purpose of the current study was to examine if isometric peak force and rate of force development (RFD) were related to the ability to successfully perform a simulated casualty evacuation task in both unweighted and weighted conditions. METHODS: Eighteen male participants from Army Reserve Officers' Training Corps (ROTC) completed a maximum isometric deadlift on a force plate (IRB#HE16227). Isometric peak force and RFD were calculated from ground reaction force. Two simulated casualty evacuation performance trials were then completed. The unweighted trial consisted of lifting and carrying a 75 kg dummy as quickly as possible for 50 m. The weighted trial was similar except 9 kg vests were added to both the simulation dummy and the participant to represent 18 kg of duty gear. Independent sample t-tests and Pearson correlations were performed to compare the characteristics of those who passed and failed the weighted trial. RESULTS: All of the participants (n = 18) completed the unweighted casualty evacuation trial, while 72% (n = 13) were able to complete the weighted casualty evacuation trial. The participants that successfully completed the weighted evacuation trial had significantly (p < 0.05) greater isometric peak force (1420 ± 165 vs. 1076 ± 256 N) and lean mass (74.18 ± 3.89 vs. 65.34 ± 3.89 kg) when compared to participants (n = 5) that could not complete the weighted evacuating task trial. Additionally, greater Army Physical Fitness Test scores (288 ± 13 vs. 269 ± 16 arbitrary units) and significantly faster (30.34 ± 4.41 vs. 44.92 ± 10.62 seconds) unweighted evacuation trial times were observed in participants that could complete the weighted evacuation task. Peak force was also significantly correlated with lean mass (r = 0.51, p < 0.05). There was no relationship between RFD and performance of the unweighted or weight trial. CONCLUSION: Isometric deadlift peak force represents an important determinant for the success of a simulated casualty evacuation task and may be a useful marker to include in periodic fitness evaluations of military personnel.

Acute Cardiovascular, Metabolic, and Muscular Responses to Blood Flow Restricted Rowing Exercise.

INTRODUCTION: Microgravity leads to a progressive loss in muscular strength, endurance, and aerobic capacity (Vo2peak). Blood flow restricted (BFR) exercise has been shown to elicit rapid gains in muscular strength and Vo2peak. Rowing exercise combined with BFR could be a supplemental countermeasure to maintain preflight muscle function and Vo2peak, especially within future space vehicles with restricted physical volume.METHODS: There were 20 men who completed 19 min of rowing exercise during CON or BFR in a randomized order. Exercise intensity for all sets was 30% of peak work load achieved during a separate incremental maximal exercise test. Kaatsu training cuffs were inflated around each leg during BFR. Muscle oxygen saturation (Smo2) and heart rate (HR) were measured throughout exercise and rest. Rate of perceived exertion (RPE) and muscle activation, using surface electromyography (sEMG), were measured during the last 30 s of each exercise set. Blood pressure (BP) and whole blood lactate ([La-]b) were measured at rest and postexercise.RESULTS: Smo2 declined significantly in BFR during exercise and rest by 13% and 14%, respectively. HR and RPE showed significant increases during BFR (120.5 ± 5.53 vs. 128.9 ± 9.86 bts · min-1) (9.8 ± 1.85 vs. 11.8 ± 1.88 arbitrary units). No differences were observed for BP, [La-]b, and sEMG.DISCUSSION: Findings indicate exercise intensity and cuff pressure elicited acute muscular, cardiovascular, and perceptual responses. BFR rowing exercise could be advantageous as an adjunct for future exercise countermeasures where aerobic and anaerobic exercise may be performed on one device or in limited physical space.Mahoney SJ, Dicks ND, Lyman KJ, Christensen BK, Hackney KJ. Acute cardiovascular, metabolic, and muscular responses to blood flow restricted rowing exercise. Aerosp Med Hum Perform. 2019; 90(5):440-446.

An Occupational-Specific O2max Protocol for Structural Firefighters.

OBJECTIVE: The aim of this study was to validate a (Equation is included in full-text article.)O2max protocol designed specifically for the occupational demands of firefighters by incorporating the use of personal protective equipment (PPE). METHODS: Career firefighters completed a stage-graded exercise test (GXT) with submaximal square-wave verification bout while wearing PPE (pants and boots) to determine (Equation is included in full-text article.)O2max. Using the self-reported Physical Activity-Rating (PA-R) scale and an estimated nonexercise regression equation of (Equation is included in full-text article.)O2max for comparison to measured. RESULTS: Twenty-eight male, career firefighters performed the GXT and square-wave bout. (Equation is included in full-text article.)O2 values (mean ±â€ŠSD) from the GXT and the square-wave verification bout were 41.04 ±â€Š6.98 and 39.74 ±â€Š6.42 mL/kg/min, respectively (ICC = 0.98, typical error = 0.96 mL/kg/min, CV = 2.4%). CONCLUSION: Our data suggest an incremental treadmill protocol that incorporates PPE and square-wave verification as an occupational-specific tool to measure cardiovascular fitness in firefighters.

Validation of the 3-Minute All-Out Exercise Test for Shuttle Running Prescription.

Saari, A, Dicks, ND, Hartman, ME, and Pettitt, RW. Validation of the 3-minute all-out exercise test for shuttle running prescription. J Strength Cond Res 33(6): 1679-1685, 2019-A 3-minute all-out exercise test (3 MT) for running has been developed to determine critical speed (CS) and finite capacity for running speeds > CS (D') which allow for the prediction of time limits (TLIMs) associated with running different distances. Most team sports require shuttle running; however, the 3 MT was validated for uninterrupted, track running and not shuttle running. The purpose of this study was to examine the efficacy of shuttle running 3 MT to determine CS and D'. A total of 12 subjects were tested using a baseline 3 MT along with 3 separate distance time trials of all-out shuttle running to determine true CS and D'. The 3 MT (2.94 ± 0.39 m·s) and the true CS (3.00 ± 0.36 m·s) for shuttle running did not differ (p = 0.71) and had a coefficient of variation (CV) of 7.7%. Conversely, D' from the 3 MT exceeded true D' by 42 m (p = 0.04, CV = 36%). The TLIMs estimated for the 3 different distances were within ∼2-6% (p = 0.60). Based on these outcomes, the shuttle run 3 MT may offer a suitable method for prescribing shuttle running interval training.

Dynamics of pleasure-displeasure at the limit of exercise tolerance: conceptualizing the sense of exertional physical fatigue as an affective response.

The search for variables involved in the regulation and termination of exercise performance has led to integrative models that attribute a central role to the brain and utilize an array of psychological terms (e.g. sensation, perception, discomfort, tolerance). We propose that theorizing about exercise regulation would benefit from establishing cross-disciplinary bridges to research fields, such as affective psychology and neuroscience, in which changes along the dimension of pleasure-displeasure are considered the main channel via which homeostatic perturbations enter consciousness and dictate corrective action (slowing down or stopping). We hypothesized that ratings of pleasure-displeasure would respond to the severity of homeostatic perturbation and would be related to time to exhaustion during exercise performed at an unsustainable intensity. In a within-subjects experiment (N=15, 13 men and 2 women, age 23.4±2.2 years; maximal oxygen uptake 46.0±8.0 ml kg-1 min-1), we compared the slope of ratings of pleasure-displeasure (acquired every 1 min) during cycling exercise at a power output 10% above critical power until volitional termination under glycogen-loaded and glycogen-depleted conditions. As hypothesized, ratings of pleasure-displeasure declined more steeply under glycogen depletion (P=0.009, d=0.70) and correlated closely with time to exhaustion under both glycogen-loaded (r=0.85; P<0.001) and glycogen-depleted conditions (r=0.83; P<0.001). We conclude that in exercise, as in other domains, changes in pleasure-displeasure may be the main channel via which homeostatic perturbations enter consciousness. This proposal may have important implications for conceptualizing and identifying the neurobiological mechanisms of the sense of exertional physical fatigue.

Validity of Critical Velocity Concept for Weighted Sprinting Performance.

We investigated the validity of a recently developed equation for predicting sprinting times of various tactical loads based upon the performance of a running 3-min all-out exercise test (3MT). Thirteen recreationally trained participants completed the running 3MT to determine critical velocity (CV) and finite running capacity for running velocities exceeding CV (D'). Two subsequent counterbalanced loaded sprints of 800 and 1000 m distances with 20 and 15% of their body mass, respectively, were evaluated. Estimated times (t, sec) for running 800 and 1000 m with a tactical load was derived using t = (D - D')/CV. Critical velocity adjusted for an added load using the following regression equation: original CV + (-0.0638 × %load) + 0.6982, D was 800 or 1000 m, and whole percentage load was ~15 or 20% of the participant's body mass. From the 3MT, CV (3.80 ± 0.5 m·s-1) and D' (200 ± 49.88 m) values were determined. The typical error of predicting actual times for the 800 and 1000 m loaded sprints were 5.6 and 10.1 s, with corresponding ICCs of 0.95 and 0.87, and coefficient of variations of 2.9 and 4.3%. The effect size differences between estimated and actual sprint times were small (0.27) and moderate (0.60) for 800 and 1000 m, respectively. The adjustment to CV through the regression equation yields small to moderate overestimates of maximally loaded sprint times for distances of 800 and 1000 m. Whether such errors remain pervasive for prescribing high-intensity interval training is unclear and requires further investigation.

Influence of Load Carriage on High-Intensity Running Performance Estimation.

Load carriage is a necessary burden for tactical athletes. A combination of training modes, including aerobic conditioning and progressive load carriage, may lead to improved performance. The critical speed (CS) concept enables the practitioner to prescribe high-intensity interval training (HIIT) time limits (TLIMs) from a single 3-minute all-out exercise test (3 MT). We sought to examine the effect of a standard load carriage (18.86 kg) on CS and the finite running capacity > CS (D'). A group of trained subjects (age: 26 ± 5 years, height: 181 ± 4 cm, body mass [BM]: 90 ± 14 kg) completed a loaded and unloaded (UL) 3 MT. The CS was reduced by 0.66 ± 0.24 m·s (p < 0.01) in the loaded condition. There was a small nonsignificant increase in D' (21.25 ± 39.53 m, p = 0.07). The higher the % load carriage relative to BM is, the greater decline in CS (r = 0.83, p < 0.01). A revised CS with load carriage from the UL 3 MT may be calculated using: adjusted CS = original CS + ([-0.0638 × %load]) + 0.6982. Our results indicate that revised CS and TLIMs for fixed distance, fixed time, or fixed speed HIIT prescriptions may be derived from a UL 3 MT. Such calculations would enable more expeditious training for tactical athletes. We recommend further research involving implementation of HIIT using this new method.

Load Determination for the 3-Minute All-Out Exercise Test for Cycle Ergometry.

PURPOSE: To investigate a new power-to-body-mass (BM) ratio 3-min all-out cycling test (3MT(%BM)) for determining critical power (CP) and finite work capacity above CP (W'). METHODS: The gas-exchange threshold (GET), maximal oxygen uptake (VO2max), and power output evoking VO2max (W(peak)) and GET (W(GET)) for cycle ergometry were determined in 12 participants. CP and W' were determined using the original "linear factor" 3MT (3MT(rpm^2)) and compared with CP and W' derived from a procedure, the 3MT(%BM), using the subject's body mass and self-reported physical activity rating (PA-R), with values derived from linear regression of the work-time model and power-inverse-time model (1/time) data from 3 separate exhaustive square-wave bouts. RESULTS: The VO2max, VO(2GET), W(peak), and W(GET) values estimated from PA-R and a non-exercise-regression equation did not differ (P > .05) from actual measurements. Estimates of CP derived from the 3MT(%BM) (235 ± 56 W), 3MT(rpm^2) (234 ± 62 W), work-time (231 ± 57 W), and 1/time models (230 ± 57 W) did not differ (F = 0.46, P = .72). Similarly, estimates of W' between all methods did not differ (F = 3.58, P = .07). There were strong comparisons of the 3MT(%BM) to 1/time and work-time models with the average correlation, standard error of the measurement, and CV% for critical power being .96, 8.74 W, and 4.64%, respectively. CONCLUSION: The 3MT(%BM) is a valid, single-visit protocol for determining CP and W'.