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8-Weeks of Moderate-Intensity Aerobic Exercise Fails to Improve VO2max in Young Adults Born Preterm
Get PDFIndividuals born preterm have significantly impaired adaptability in maximal aerobic capacity (VO2 max) with exercise training. We have hypothesized that this impaired response is linked to immature mitochondrial development and maladaptation resulting from early birth. PURPOSE: This project is multifaceted with the overarching aim to measure mitochondrial respiration in peripheral blood mononuclear cells (PBMCs) and assess for potential mitochondrial genome variants and heteroplasmy that may explain poor adaptability in VO2 max with training. The purpose of this report is to confirm poor adaptability in VO2 max in preterm adults. METHODS: This is an ongoing project. Young adults aged 18-35 years who were born preterm (\u3c 37 weeks gestational age) and term controls (≥ 37 weeks gestational age) are undergoing 16-weeks of aerobic exercise training program at 65-75% of HRmax. Exercise consists of walking or running and VO2 max is measured at four time points: before training, at 4 weeks, at 8 weeks, and after completing the 16-week training. RESULTS: Data presented here is from four female participants ( age25.5 ± 4.42) born prematurely that completed eight of the 16 weeks of training. At baseline, VO2 max was 26.1 ± 4.2 ml/kg/min (range = 10.61). No difference was found at 4 weeks (27.9 ± 4.7 ml/kg/min) or after 8 weeks (28 ± 7.0 ml/kg/min) of training (one-way ANOVA p=0.28, p = 0.90). As secondary measures, we did not find a change in BMI (p = 0.90) or resting heart rate (p = 0.51) over time. CONCLUSION: Our early interim analysis indicated that 8 weeks of moderate-intensity aerobic training are likely ineffective at increasing VO2 max in young women born preterm, which aligns with prior work. Further, the minimal increase in VO2 max we have observed thus far is still in the ‘below average’ category of recommendations set by the ACSM. Our continued work will assess mtDNA and mitochondrial respiration in PBMCs as molecular targets potentially linked to poor VO2 max trainability among this population
Added Psychological Stress Significantly Increases Anxiety but Does Not Impact Stress Biomarkers in Response to Combined Mental and Physical Stress
Get PDFHigh Stress occupations are subject to significant health risk due to the exposure to a variety of stressors, specifically the exposure to concurrent stressors (i.e., combined mental and physical stress). Exposure to concurrent stressors has been shown to exacerbate the stress response, potentially resulting in cardiovascular strain, immune suppression, and inflammation. PURPOSE: The purpose of this study was to examine the effect of a concurrent stress challenge (CSC) on markers of stress, as well as perceived anxiety. METHODS: This study utilized a randomized control trial, in which fifty-four subjects (n=54) were randomly assigned to perform either exercise alone (EA), or a CSC. The EA condition consisted of the Ruffier squat test (30 squats in 45 seconds), while the CSC included the exercise immediately followed by a virtual reality active shooter drill previously demonstrated to elicit a significant stress biomarker response. A saliva sample, heart rate (HR) measurement, and state anxiety inventory (SAI) survey were collected four times throughout the study: 1) 30 minutes prior to exercise 2) immediately prior to exercise 3) 5 minutes following exercise, and 4) 30 minutes following exercise. Saliva samples were analyzed for concentrations of stress biomarkers: salivary alpha amylase (sAA) and secretory immunoglobulin-A (SIg-A). RESULTS: No treatment x time interactions were noted for sAA, SIg-A, and HR; however, immediately post-stress all variables were significantly higher as compared to all other time-points. With respect to SAI, a significant (p \u3c 0.05) interaction was noted. Post hoc analysis indicated no significant changes from pre to post stress challenge in EA; however, a significant increase in SAI was found from pre to immediately post stress in the CSC condition. CONCLUSION: This study found that following stress, the EA and CSC conditions resulted in significant increases in physiological markers of stress. Moreover, the CSC condition resulted in increased SAI post stress compared to EA. In conclusion, it can be determined that adding mental stress to physical stress results in increases in perceived anxiety. These findings provide implications that high stress occupations may be at an increased risk to health complications due to the exposure to concurrent stress
Effects of Acute Lower Body Resistance Exercise on Body Composition Parameters Assessed by Bioelectrical Impedance Analysis
Get PDFBioelectrical Impedance Analysis (BIA) has the capability to estimate skeletal muscle mass (SMM), total body water, and body fat mass (FM) for assessment of body composition. Various factors are thought to influence the accuracy of BIA estimated body composition. PURPOSE: The purpose of this study was to investigate acute changes in BIA SMM and FM results after a prescribed lower body exercise compared to a non-exercise treatment. METHODS: Participants (n = 14; 22.71 ± 1.63 years; 169.42 ± 13.23 cm; 80.79 ± 17.71 kg) completed each trial in a randomly assigned crossover experimental design: resting conditions (REST) and a prescribed lower body workout (LBRE) consisting of 4 sets of 12 repetitions on leg press, leg curls, leg extension, and kettlebell squat. BIA scans were conducted prior to LBRE, immediately post LBRE, and again at 30 and 60 minutes. Linear mixed-effects models were used to evaluate the effect of time, condition, and their interaction, while random intercepts were included to account for between-participant variability. The model was fitted using restricted maximum likelihood estimation. Data was analyzed using R software. RESULTS: No condition by time interactions were present for any BIA body composition variable. However, select effects of time or condition were found. Irrespective of condition, total lean mass estimates at 60 minutes post exercise were ~0.6 kg lower than at baseline (ppCONCLUSIONS: Although it is thought that exercise may affect the reliability of the BIA, an acute bout of lower body resistance exercise did not meaningfully influence group-level BIA estimates in a recreationally active population. Thus, guidelines suggesting to abstain from resistance exercise prior to a BIA might not be essential for some applications, which could allow for greater flexibility in scheduling of body composition assessments
Associations of Skeletal Muscle Index, Body Mass Index, and Body Fat in a Primarily Hispanic Population
Get PDFDespite criticism of body mass index (BMI) in the classification of weight status, it is still a commonly used metric. BMI may still serve a purpose in the identification of low muscle status. PURPOSE: This study associated skeletal muscle index (SMI), BMI, and body fat percentage (PBF) in a population of mostly Hispanic individuals. METHODS: 47 adults, aged 18+, were assessed for total body composition using a four-compartment model (4C) with bone mineral content from a Lunar iDXA (GE Healthcare, Madison WI), total body water via the InBody 770 (InBody, Seoul, South Korea), and ADP from a BodPod GS-X (COSMED, Rome, Italy). Participants were instructed to arrive hydrated, with manufacturer suggested clothing, for testing after a minimum 4-hour fast and abstain from exercise for the previous 12 hours. Hydration was assessed before testing using a urine refractometer with an acceptable range between 1.004-1.029. Participants repeated the testing protocol on a separate day within a two-week period for reliability measures. 4C PBF was calculated with the Fuller equation embedded in the BodPod software. Pearson correlations were used to assess the relationship between BMI, PBF, and the SMIs. The sample was also divided by sex and overweight status with the same correlational analyses. Overweight was defined as BMI\u3e30 or PBF \u3e 25% in men or \u3e 32% in women. Statistical analyses were conducted using SPSS v28 (IBM Corporation, New York, USA) and alpha was set at 0.05. RESULTS: Total sample BMI was significantly correlated with SMI from DXA (r=0.719, p\u3c0.001), SMI from InBody (r=0.734, p\u3c0.001), and PBF (r=0.419, p\u3c0.01). Women’s BMI (n=22) was significantly correlated with SMI from DXA (r=0.831, p\u3c0.001), SMI from InBody (r=0.777, p\u3c0.001), and PBF (r=0.89, p\u3c0.001). For men (n=25) BMI was significantly correlated with SMI from DXA (r=0.671, p\u3c0.001), SMI from InBody (r=0.774, p\u3c0.001), and PBF (r=0.644, p\u3c0.001). Overweight (n=17) BMI was significantly correlated with SMI from DXA (r=0.721, p\u3c0.001), SMI from InBody (r=0.719, p\u3c0.001), but not for PBF (r=0.429, p= 0.09). CONCLUSION: BMI has been criticized for classifying weight status. The lack of an association for BMI with PBF in our overweight sample seems to support the criticism. There is some potential for prescreening with BMI as an indicator for low muscle mass, though a follow-up assessment in an older population would be advised before utilizing BMI in this manner
A Comparison of DXA, InBody, and BodPod for Assessing Body Fat Percentage
Get PDFWhile numerous methods for assessing body fat percentage have been validated, it is important to understand that using results from one modality does not guarantee the same on another. It is also important, when weighing the pros and cons of each modality, that the reliability of each approach should also be taken into consideration. PURPOSE: This study compared body fat percentages (PBF) derived from dual-energy X-ray absorptiometry (DXA), bioelectrical impedance (BIA), and air displacement plethysmography (ADP). Reliability was also determined for each modality. METHODS: 47 adults, aged 18+, were assessed for total body composition with a Lunar iDXA (GE Healthcare, Madison WI), InBody 770 (InBody, Seoul, South Korea), and BodPod GS-X (COSMED, Rome, Italy). Participants were instructed to arrive hydrated, with manufacturer suggested clothing, for testing after a minimum 4-hour fast and abstain from exercise for the previous 12 hours. Hydration was assessed before testing using a urine refractometer with an acceptable range between 1.004-1.029. Tests were repeated on a separate day, within a two-week period. Additionally, a four-compartment measure of PBF (4C) was calculated using bone mineral content from DXA, total body water from BIA, and ADP. One-way ANOVA compared an average of the two testing days for the four measures of PBF with a Bonferroni correction used breakdown of significant main effects. Reliability was determined using coefficient of variation percent (CV) and root mean square standard deviation at a 95% confidence interval (RMS). All statistical analyses were conducted using SPSS v28 (IBM Corporation, New York, USA) and alpha was set at 0.05. RESULTS: One-way ANOVA showed significant differences between the four measures of PBF F(1,46)= 417.2, pCONCLUSION: As mentioned previously, values derived from the different methods can yield different results and it is important to choose a single method when tracking individual or group changes across time. Additionally, choosing a method with lower variation can better ensure that any changes seen in PBF are due to interventions, not machine or tester error
Effects of a 12-Week Chair-Based Exercise Program on Functional Fitness and Cognitive Function in Older Females
Get PDFAging is associated with declines in functional fitness and cognitive function, which may impact the quality of life in older adults. Developing a safe and active training program as an initial strategy is critical for the elderly population to maintain physical and mental well-being. PURPOSE: This study aimed to evaluate the effects of a 12-week chair-based exercise intervention on functional fitness, cognitive function, and nutritional status in older female adults. METHODS: Thirty-six healthy female participants aged 55 to 80 years were randomly assigned to the exercise group (Ex, N=19; Age: 64±1 years; BMI: 24.7±0.8 kg/m²) or the control group (CTRL, N=17; Age: 66±1 years; BMI: 24.6±0.7 kg/m²). The Ex group participated in a structured chair-based exercise program twice per week, with each 60-minute session comprising a 10-minute warm-up (joint mobility and large muscle activities), a 35-minute progressive chair-based workout focusing on upper/lower limb muscular endurance using water bottles and body weight resistance, and a 15-minute stretching cooldown. The CTRL group received health education materials and maintained their usual lifestyle. The intervention was approved by the Institutional Review Board (IRB). Assessments included body composition, Mini Nutritional Assessment (MNA), exercise heart rate response, functional fitness (static balance, grip strength, cardiopulmonary fitness), and cognitive function (Montreal Cognitive Assessment, MoCA). RESULTS: The chair-based exercise program effectively increased heart rate response compared to the control group, who followed self-directed activities based on health education materials (Ex: 1786 bpm x min vs. CTRL: 1346 bpm x min, p0.05). Functional fitness improved significantly in the Ex group, including static balance (+484% above CTRL, p=0.048) and cardiopulmonary fitness (+74.3% above CTRL, p=0.047), while grip strength showed a trend toward improvement (+134% above CTRL, p=0.063). Cognitive function, measured by MoCA, was significantly improved in the Ex group compared to the CTRL group (+1.49 score above CTRL, p=0.024). CONCLUSION: A 12-week chair-based exercise program featuring chair support to enhance stability and prevent falls during dynamic exercise significantly improved physical activity levels, functional fitness, and cognitive function in older females. The findings highlight its potential as a safe and effective intervention for healthy aging
Extended Rest Requirement after Shoulder Surgery: A Case Study
Get PDFCASE HISTORY: The patient was a 21-year old right-handed collegiate female volleyball player who presented with chronic shoulder pain in her dominant shoulder, which began approximately five years ago. Her previous assessment and treatment included x-rays and MRI imaging, several joint injections, and daily rehabilitation in an attempt to manage her symptoms. Unfortunately, her shoulder problems persisted. Four years after the onset of her pain, she underwent surgery as it was deemed necessary, due to her consistent pain and functional limitations. PHYSICAL EXAM: The patient reported sharp pain (7/10) during overhead activities. Strength was 3+/5 on flexion and abduction, 4/5 on internal rotation, 3/5 external rotation. Positive Empty Can Test for pain and weakness. Negative Sulcus Sign Test. DIFFERENTIAL DIAGNOSIS: Anterior shoulder instability; rotator cuff tear; impingement syndrome; labral tear. TESTS & RESULTS: MRI revealed a partial rotator cuff tear and the presence of a large loose body in shoulder joint. Clinical testing indicated instability and symptoms of impingement. FINAL DIAGNOSIS: Anterior shoulder instability with impingement syndrome, partial rotator cuff tear, and a 5mm intra-articular loose body. DISCUSSION: Shoulder injuries are common among overhead athletes, with labral tears and instability presenting significant challenges. Without early diagnostic imaging, extended rehabilitation may be insufficient. In this case, the athlete completed nearly four years of daily corrective exercises before undergoing diagnostic imagining. Once the imaging showed injuries that required surgical intervention, surgery was performed. However, post-operative rehabilitation only regained strength and range of motion; it did not alleviate pain. Ultimately, the athlete only achieved pain relief when she stopped all activity, including rehabilitation, for six months. This case study highlights the complexity of treating shoulder instability and the importance of rest when pain does not subside after traditional treatments. OUTCOME OF THE CASE: Arthroscopy of the right shoulder was performed. The procedure included glenoid labral repair with Arthrex anchors, acromioplasty, extensive debridement of the labrum and rotator cuff, and loose body removal. The patient engaged in post-operative rehabilitation and progressively regained strength in shoulder function. However, she still experienced pain. RETURN TO ACTIVITY: After discontinuing rehabilitation for an extended amount of time, she was able to slowly return to activity. She was able to participate in practices and games without pain in her final collegiate season
Range of Motion & Strength in the Shoulder of Female Athletes
Get PDFGiven the extensive shoulder movements in athletes who perform overhead movements, it was anticipated that these athletes would present with stronger shoulders that could achieve a greater range of motion. PURPOSE: This study examined shoulder range of motion (ROM) and isometric strength in internal (IR) and external (ER) rotation in overhead (OH) and non-overhead (NO) athletes. METHODS: Twelve OH female athletes (19.9±0.9 yr, 174.4±6.4cm, 68.1±9.6 kg) and 10 NO female athletes (20±0.9 yr,167.4±6.3 cm, 64.9±10.4 kg) participated from an NCAA Division 3 school. Exclusion criteria included male athletes, athletes with shoulder injuries, dual sport athletes, and non-athletes. Participants completed a shoulder warm-up and three trials of each assessment. The range of motion was measured using a standard protocol digital goniometer (GemRed, Guilin, China). Strength was measured using a hand-held dynamometer (Mark-10 Series 3, Copiague, NY) during internal and external rotation of the dominant shoulder. A 2x2 (shoulder movement x group) mixed-model ANOVA was used to compare ROM and strength between athlete groups and shoulder movement. RESULTS: Non-overhead athletes produced 69.5 (9.8) and 81.1 (8.6) degrees, and overhead athletes produced 70.0 (7.0) and 78.8 (7.9) degrees of internal and external rotation, respectively. Non-overhead athletes produced 10.4 (2.0) and 8.9 (1.5) kgf, and overhead athletes produced 12.3 (2.4) and 10.7 (2.1) kgf of force in internal and external rotation, respectively. Non-overhead athletes produced 16.3 (4.1) and 14.1 (3.2) %BM, and overhead athletes produced 18.2 (4.1) and 15.6 (3.3) %BM of normalized force in internal and external rotation, respectively. No interaction was found between group and shoulder movement for ROM, strength, or normalized strength (p\u3e0.05). No significant difference in ROM between OH and NO athletes (p = 0.747). OH athletes produced significantly more force than NO athletes (p = 0.035), but this difference was non-significant when comparing forces normalized to body mass (P\u3e0.05). CONCLUSION: The ROM between OH and NO behaved similarly for IR and ER in the shoulder. This finding might suggest that similar training routines would be appropriate for each group
Short-Distance and Rotational Deceleration as Key Determinants of High-School Basketball Agility: A Preliminary Clustering Analysis
Get PDFDeceleration ability is fundamental to basketball performance, influencing change of direction, defensive positioning, and movement efficiency. While linear deceleration is commonly assessed, rotational deceleration’s role in basketball-specific agility remains relatively underexplored on the high-school level. Overlooking the unique force demands, joint angles, and neuromuscular control required to stop and change direction rotationally, may hinder athlete preparation, injury prevention, and training effectiveness. PURPOSE: To determine the relationship between rotational deceleration (505 Left/Right), linear deceleration (5m/10m Decel), and lateral agility (5-5 Lateral Shuffle Left/Right) in high-school basketball players and identify the key determinant of agility performance. METHODS: Thirty-three male high-school basketball athletes from two teams (n1=19, n2=14) completed a series of six deceleration and agility tests: (1) 5m Decel: A 5-meter sprint followed by a controlled stop (deceleration).; (2) 5-5 Lateral Shuffle Left: Side-stepping or shuffling to the left for 5 meters, then returning another 5 meters; (3) 10m Decel: A 10-meter sprint followed by a controlled stop; (4) 505 Left: Run forward, then perform a 180° turn off your left foot after 5 meters, and sprint back 5 meters.; (5) 505 Right: Same as the 505 Left, but pivoting on the right foot.; and (6) 5-5 Lateral Shuffle Right: Similar to the left shuffle, but moving to the right first, then back 5 meters. Data were collected using Speed 1 (1080 Motion, Sweden). Statistical analyses included correlations, multiple regression, principal component analysis (PCA), and k-means clustering in MATLAB. RESULTS: The 505 Left showed the strongest association with lateral shuffle performance (r = .72, p \u3c .01), identifying rotational deceleration as a primary contributor to agility in basketball. The 5m Decel emerged as the strongest predictor of rotational deceleration (β = .67, p = .0015, R2 = .38), whereas the 10m Decel was not significant (β = −.02, p = .97), reinforcing the sport-specific importance of short-distance stopping ability. PCA confirmed 505 Left as the dominant deceleration metric, explaining 59.6% of variance across all movement tasks. Additionally, k-means clustering of 5m Decel and 505 Left data revealed three distinct performance subgroups, reinforcing the practical value of these measures for individualized training approaches. CONCLUSION: These findings highlight rotational deceleration as the key performance differentiator in basketball agility, with 5m Decel serving as the best predictor of rotational stopping ability. Training programs should emphasize rotational control and short-distance braking mechanics over longer deceleration distances to enhance lateral agility and defensive movement efficiency. Clustering outcomes further underscored the practical value of these measures for tailoring training strategies to each athlete’s unique profile. Future research should validate these findings in larger samples/higher-level basketball players and implement machine learning models for individualized profiling
Assessment of Estimated Pulse Wave Velocity and Body Roundness Index among First Responders
Get PDFFirst responders have a heightened cardiovascular disease (CVD) risk. Estimated pulse wave velocity (ePWV) and body roundness index (BRI) are associated with CVD risk. These parameters may provide a more comprehensive insight into the risk of CVD and premature mortality than conventional parameters (i.e., blood lipids). PURPOSE: This study assessed the relationship between ePWV, BRI, and several conventional CVD risk, fitness, and body composition parameters and compared these variables between sub-first responder groups. METHODS: One hundred and seventy-one (n=171) first responders (98 firefighters [FF] and 73 law enforcement officers[LEO]) completed a battery of clinical testing during an annual physical assessment, wherein they underwent a dual-energy X-ray absorptiometry (DEXA) scan, had their waist and hip measurements and resting hemodynamics (i.e., blood pressure) taken, donated a fasted (≥12 hours) blood bio-sample (to assess blood lipids and glucose), and completed a maximal cardiopulmonary exercise test (CPXT). The resting hemodynamics measurements were used to calculate ePWV, while waist circumference and height were used to calculate BRI. Bivariate Pearson correlation matrix analysis was used to examine the relationship between body composition and fat distribution ePWV, BRI, and several conventional CVD risks (i.e., blood lipids, glucose, and BMI) and body composition parameters (i.e., android, gynoid, body fat percentage, lean mass, and fat mass). A Shapiro-Wilk Test was used to assess normality for comparing FF and LEO. Then, independent sample T-tests or non-parametric Mann-Whitney U tests (if normality was violated) were used to assess differences in the outcomes between the FF and LEO. Effect sizes were calculated as Cohen’s d (i.e., small [0.2-0.5], medium [0.5-0.8], large [\u3e0.8]). RESULTS: The Bivariate Pearson correlation matrix revealed (p\u3c0.05) that ePWV positively correlated with age and blood glucose while inversely correlated with CPXT time to exhaustion and VO2max. BRI was inversely correlated with CPXT time to exhaustion, VO2max, and high-density lipoprotein cholesterol concentrations. The FF displayed greater WHR (FF: 0.95±0.06; LEO: 0.89±0.08; d=0.792), but lower ePWV (FF: 6.91±0.74 m/s; LEO: 7.23±0.82 m/s, d=-0.419) and hip circumferences (FF: 38.5±4.5 in; LEO: 41.5±3.42 in, d=-0.725) than their LEO counterparts, with no other differences in the outcome variables. CONCLUSION: These data demonstrate that first responders should aim to maintain their fitness to counter increases in CVD risk parameters, such as ePWV and BRI. Although the LEO demonstrated a higher ePWV than the FF, the values were within the low-risk range (i.e., 5 to 15 m/s). Both first responder groups should benefit from structured aerobic and resistance training programming to improve their fitness. Future work should explore the impact of these fitness programs on ePWV and BRI