Effect of Extreme Volume-Load Differences for a Single Unilateral Exercise During In-Season Resistance Training on Measures of Bilateral Strength, Power, and Speed in Collegiate American Football Players.

ABSTRACT: Crawley, K, Adams, KJ, DeBeliso, M, and Lawrence, MM. Effect of extreme volume-load differences for a single unilateral exercise during in-season resistance training on measures of bilateral strength, power, and speed in collegiate american football players. J Strength Cond Res 38(1): 80-89, 2024-This study examined the impact extreme volume-load differences for a single weekly exercise, when all other exercises' volume loads were similar, would have on American football performance variables after in-season resistance training (RT). Twenty male National Collegiate Athletic Association (NCAA) American footballers (18-23 years, 98.4 ± 19.3 kg) were randomly assigned to an extreme high-volume low-intensity (EHVLI; n = 11) group or a low-volume high-intensity (LVHI; n = 9) group. Subjects performed the same evidence-based RT exercises and volume loads for 8 weeks thrice weekly, with the only differences being once weekly unilateral reverse dumbbell lunge (EHVLI) or unilateral Hatfield safety bar back squat (LVHI) exercises performed with different volume loads. Performance variables were assessed 1 week before (PRE) and after (POST) 8 weeks of RT. A 2-way analysis of variance with repeated measures and the Sidak post hoc test were used ( p < 0.05). Extreme high-volume low-intensity had no significant ( p > 0.05) PRE-to-POST RT changes in muscular strength in 1 repetition maximum (251.8 ± 48.7 to 274.6 ± 61.3 kg) or power in vertical jump (79.2 ± 8.8 to 78.2 ± 10.8 cm). Conversely, LVHI had significant ( p < 0.05) PRE-to-POST RT improvements in strength (249.2 ± 54.4 to 284.1 ± 55.0 kg) and power (72.8 ± 11.4 to 76.3 ± 10.0 cm). Furthermore, LVHI vs. EHVLI displayed significantly greater percentage difference increases from PRE values in muscular power (6.7% ± 7.2 vs. -1.3% ± 6.0, respectively), with no significant differences between groups (LVHI vs. EHVLI) in muscular strength (8.8% ± 3.1 vs. 6.7% ± 8.0, respectively) and 10-yard acceleration (2.2% ± 5.6 vs. 3.2% ± 5.6, respectively). For in-season RT of strength and power in collegiate American football players, all exercises performed should use evidence-based volume loads to optimize adaptations because a single exercise performed with extreme volume load may limit muscular strength and power development.

Resting Blood Pressure in Master Athletes: Immune from Hypertension?

Ageing is associated with decreased physical activity, obesity and increased risk of hypertension (HTN). Master athletes (MA) have either pursued a physically active lifestyle throughout their life or initiated exercise or sport later in life. We assessed resting blood pressure (BP) in male and female World Masters Games (WMG) athletes. This was a cross-sectional, observational study which utilized an online survey to assess the blood pressure (BP) and other physiological parameters. Results: a total of 2793 participants were involved in this study. Key findings included differences between genders with males reporting higher resting SBP (+9.4%, p < 0.001), resting DBP (+5.9%, p < 0.001) and mean arterial pressure (+6.2%, p < 0.001). Significant differences (p < 0.001) were also identified when comparing WMG athletes' resting BP results (genders combined) to the general Australian population with WMG athletes having a lower SBP (p < 0.001, -8.4%) and DBP (p < 0.001, -3.6%). Additionally, 19.9% of males and 49.7% of female WMG participants were normotensive whereas 35.7% of the general Australian population were normotensive. Only 8.1% of the WMG athletes (genders combined) were found to be HTN compared to 17.2% in the general Australian population. These findings reflect a low prevalence of HTN in WMG participants and support our hypothesis of a low prevalence of HTN in an active, but aged cohort of MA.

The Relationship Between Partial and Full Range of Motion Deadlift 1-Repetition Maximum: A Technical Note.

ABSTRACT: Gillingham, B, Bishop, A, Higa, GK, Adams, KJ, and DeBeliso, M. The relationship between partial and full range of motion deadlift 1-repetition maximum: a technical note. J Strength Cond Res 37(4): 909-914, 2023-The full range of motion (FROM) or partial range of motion (PROM) deadlift (DL) are often included in resistance training (RT) programs and are performed by strength athletes in competition. This study examined the relationship between the FROM and PROM 1-repetition maximum (1RM) DL and if the PROM 1RM DL can be estimated by the FROM 1RM DL. Eighteen National Collegiate Athletic Association wrestlers (20.8 ± 1.2 years, 176.0 ± 5.2 cm, 78.9 ± 10.6 kg) performed a warm-up followed by the assessment of the FROM and PROM 1RM DLs. The FROM DLs were executed with a starting position of the bar resting on the lifting platform. Partial range of motion DLs were executed in a power rack with the bar starting position at ≈2.54 cm above the patella. Regression analysis was employed to estimate PROM 1RM DL based on FROM 1RM DL, body height, and mass. A Pearson's correlation coefficient ( r ) was used to compare the PROM 1RM DL with FROM 1RM DL. A dependent t test was used to compare the PROM 1RM DL and FROM 1RM DL scores (α < 0.05). The PROM 1RM DL scores (226.0 ± 40.6 kg) were significantly greater than the FROM 1RM DL scores (191.7 ± 37.2 kg) ( p < 0.05: effect size = 0.92). The PCC between the PROM and FROM 1RM DL was r = 0.85 ( p < 0.05). The regression coefficient for the FROM 1RM DL was significant ( p < 0.05; R = 0.85, R2 = 0.73). The regression coefficients for body mass and height were not significant ( p > 0.05). The PROM and FROM DL may be interchangeable modalities within an RT program, and the PROM 1RM DL can be accurately predicted by the FROM 1RM DL.

Prevalence of hyperglycemia in masters athletes.

Background: Ageing is associated with decreased physical activity, obesity and subsequently an increased risk of developing type 2 diabetes mellitus (T2dm). Master athletes (MA) have initiated exercise or sport later in life or pursued a physically active lifestyle for an extended period. Subsequently, MAs have been proposed as a model of successful ageing as this active lifestyle is associated with health benefits including decreased health risk of chronic diseases and a reduction in premature mortality. Given long-term physical activity/exercise has previously been shown to be protective against hyperglycemia, a risk factor for T2dm, it is plausible that MA may have protective benefit against developing hyperglycemia. Therefore, the aim of this study was to investigate the prevalence of hyperglycemia via fasting plasma glucose (FPG) in MAs competing at the World Masters Games (WMG). Methods: This cross-sectional, observational survey utilized an online survey using open-source web-based software was used to investigate MAs physiological and medical-related parameters. Over 28,000 MAs competed in the WMG, of which 8,072 MAs completed the survey. Of these MAs, a total of 486 (males 277, females 209; range 27 to 91 years, mean age 55.1 ± 10.2 years) attained recent pathology results which included FPG which was subsequently analyzed for this study. FPG and other outcome variables were compared between genders and to the Australian and United States general population. Results: Mean FPG for MAs was 5.03 mmol (±1.2, 95% CI [4.9-5.1] mmol) with majority (75.5%) of MAs reporting a normal (<5.5 mmol) FPG, followed by pre-diabetes (20.2%, >5.51 to <5.99 mmol) and abnormal (4.3%, >7.0 mmol). There was no significant difference (P = 0.333) in FPG between genders however, males had a slightly higher (+2.1%) FPG as compared to females (5.08 ± 1.2 mmol (95% CI [4.9-5.22] mmol) versus 4.98 ± 1.1 mmol (95% CI 4.8-5.1 mmol)). The majority of males (71.8%) and females (80.3%) were classified with a normal FPG. With regard to an abnormal FPG level, only 4.0% of males and 4.9% of females were classified abnormal which was suggestive of undiagnosed T2dm. With regard to age by decade, there was no significant difference (P = 0.06-1.00) between age groups and no relationship between the MAs' age and FPG (r = .054, P = 0.24). As a group, MAs had a significantly lower FPG as compared to the Australian (-3.2%, P = 0.005) and United States general populations (-13.9%, P < 0.001). Conclusions: Most, however not all, MAs were found to have normal glycaemia, with only a small percentage indicating a risk of developing T2dm (i.e., impaired fasting glucose) and a smaller percentage identified with an abnormal FPG, suggestive of T2dm. These findings suggest MAs appear to be at low metabolic risk for developing T2dm based upon FPG and the physical activity/exercise they complete as MAs may indeed be protective against hyperglycemia whilst maintaining an active lifestyle.

Tactical Masters Athletes: BMI Index Classifications.

Understanding the nexus between aging, physical activity, and obesity has been a source of ongoing investigation. A considerable amount of research has focused on Masters athletes in this regard, suggesting a beneficial relationship between Masters sport participation and a healthy body mass index (BMI). Some consider Active Duty military personnel as tactical athletes. As such, it is of interest to determine if aging Active Duty military personnel (or Masters Tactical Athletes) might have a similar BMI as other Masters athletes (MA). As such, this investigation examined previously recorded data of Active Duty Enlisted United States Marines (n = 402, male, 46-50 years old). The BMI of the Marines was stratified into categories of: underweight, normal, overweight, and obese. The Marines obesity prevalence was compared to US adult males (40-59 years) as well as male North American MA who competed at the 2009 Sydney World Masters Games. The Marines obesity prevalence was significantly lower than US adult males (p < 0.001) and those MA that competed in softball (p < 0.001); however, it was similar to MA that competed in football, track/field, swimming, and volleyball (p > 0.05). The average Marine BMI = 26.7 kg/m2 was similar to MA who competed in football, swimming, and volley ball (p > 0.05); however, it was higher than MA who competed in track/field (p < 0.05) and lower than MA who played softball (p < 0.05). It should be noted that the average BMI for the Marines and all MA sport categories were classified as being overweight. Within the parameters of this investigation, Tactical MA (i.e., aging US Marines) enjoy a similar beneficial BMI as other North American MA.

Growth hormone receptor knockout: Relevance to xenotransplantation.

Xenotransplantation research has made considerable progress in recent years, largely through the increasing availability of pigs with multiple genetic modifications, effective immunosuppressive therapy, and anti-inflammatory therapy to protect pig tissues from the primate immune and inflammatory responses and correct molecular incompatibilities. Further study is required regarding identification and investigation of physiological incompatibilities. Although the exact cause remains uncertain, we and others have observed relatively rapid growth of kidney xenografts after transplantation into nonhuman primates (NHPs). There has also been some evidence of growth, or at least ventricular hypertrophy, of the pig heart after orthotopic transplantation into NHPs. Rapid growth could be problematic, particularly with regard to the heart within the relatively restricted confines of the chest. It has been suggested that the problem of rapid growth of the pig organ after transplantation could be resolved by growth hormone receptor (GHR) gene knockout in the pig. The GHR, although most well-known for regulating growth, has many other biological functions, including regulating metabolism and controlling physiological processes. Genetically modified GHRKO pigs have recently become available. We provide data on their growth compared to comparable pigs that do not include GHRKO, and we have reviewed the literature regarding the effect of GHRKO, and its relevance to xenotransplantation.

Cardiovascular and Psychophysical Response to Repetitive Lifting Tasks in Women.

BACKGROUND: Understanding the cardiovascular and psychophysical demands of repetitive lifting tasks is important in job design strategies. This study determined the cardiovascular (oxygen consumption (VO2) and heart rate (HR) and psychophysical response to repetitive lifting tasks in women. METHODS: Ten female (age 27 ± 5 yrs) participants transferred 11.4, 15.9, and 20.5 kg weights back and forth from a rung 40.6 cm high to a rung 156.2 cm high. Rungs were 195.6 cm apart horizontally. Three, 10 minute bouts (1 = 11.4 kg; 2 = 15.9 kg; 3 = 20.5 kg) were performed at 6 lifts per minute. Cardiovascular and psychophysical (rating of perceived exertion, RPE) parameters were monitored throughout the bouts. VO2max and HRmax were determined via a maximal treadmill test. RESULTS: VO2, HR, and RPE were significantly different between each work bout (p < 0.01), with each outcome variable increasing as load increased. VO2max and HRmax equaled 46.5 ± 7.5 mL·kg-1·min-1 and 191 ± 11 bpm, respectively. Work at 11.4 kg was performed at 38% VO2max and 63% HRmax; at 15.9 kg at 41% VO2max and 72% HRmax; and at 20.5 kg at 49% VO2max and 81% HRmax. RPE at 11.4, 15.9, and 20.5 kgs were: 8.4 ± 1.6, 11.4 ± 1.9, and 15.0 ± 2.2. CONCLUSION: During these repetitive lifting tasks, metabolic cost and perceived exertion increased with weight lifted; average work intensity ranged from 63 to 81% of HRmax and 38 to 49% of VO2max. Results have important implications in relation to job pacing and design, and worksite health promotion strategies aimed at reducing work place injury.

Comparison of Forward and Reverse Wingate Anaerobic Tests: A Brief Technical Note.

BACKGROUND: The Wingate anaerobic test (WAT) is traditionally performed in the forward pedaling direction on a cycle ergometer. However, reverse (backward) pedaling during a WAT test may be a novel way to convey meaningful information related to performance and rehabilitation. This study compared peak power measurements between 30-second forward pedaling WAT (FWAT) with a 30-second reverse pedaling WAT (RWAT). METHODS: 10 male and 10 female participants (age 27.6 ± 7.31 yrs, mass 74.9 ± 21.3 kg and height 172.6 ± 10.9 cm) volunteered to participate. Participants performed one FWAT and one RWAT at 7.5% of body mass on a specially modified Monark cycle ergometer. Tests were separated 2 days of rest. Peak power output (PPO), mean power output (MPO), relative PPO (RPPO), relative MPO (RMPO), fatigue index (%FI), and rating of perceived exertion (RPE) were measured. RESULTS: The FWAT power measurements were all significantly greater (p < 0.05) than RWAT power measurements except MPO (p > 0.05); and that RPE was significantly greater (p < 0.05) in FWAT than RWAT. Specifically, FWAT vs. RWAT (M ± SD) are as follows: PPO watts (w) = 731.7 ± 237.1 vs. 529.6 ± 192.2; RPPO w/kg = 10.2 ± 2.3 vs. 7.2 ± 1.6; MPO w = 510.2 ± 162.1 vs. 415.1 ± 146.2; RMPO w/kg = 7.3 ± 1.5 vs. 5.8 ± 1.3; %FI = 49.2 ± 8.7 vs. 37.4 ± 13.7; and RPE = 19.4 ± 1.1 vs. 15.8 ± 1.5. Gender did not impact the relative differences in these relationships. CONCLUSION: Practitioners and clinicians may use this information to begin to understand the power and perceived exertion relationships of forward versus reverse pedaling during a WAT; exercise prescription for rehabilitation and performance may benefit.

Reliability and Criterion Validity of the Assess2Perform Bar Sensei.

The Assess2Perform Bar Sensei is a device used to measure barbell velocity for velocity-based training that has not yet been validated. The purpose of this study was to determine criterion validity and reliability of the Assess2Perform Bar Sensei in barbell back squats by comparing it against the GymAware PowerTool, a previously validated instrument. Sixteen injury-free, resistance-trained subjects (eleven males and five females) were recruited. Subjects were tested for their back squat one repetition maximum (1RM). Then, on two separate days, subjects performed two sets of three repetitions at loads of 45%, 60% and 75% 1RM. The GymAware PowerTool and Bar Sensei were attached to the barbell in similar locations for concurrent collection of mean concentric velocity (MCV) and peak concentric velocity (PCV). The Bar Sensei and PowerTool showed generally fair to poor agreement for MCV and PCV when subjects lifted 45% of 1RM (intraclass correlation;ICC 0.4-0.59), and they showed poor agreement when subjects lifted 60% and 75% of 1RM (ICC 0.3-0.4). Inter-repetition/within-set reliability for the Bar Sensei ranged between ICC = 0.273-0.451 for MCV and PCV compared to the far more reliable PowerTool (ICC = 0.651-0.793). Currently, the Bar Sensei is not a reliable or valid tool for measuring barbell velocity in back squats.

Cardiovascular risk profiles of world masters games participants.

BACKGROUND: Increasing evidence indicates adherence to exercise throughout life is concurrent with improved health. World masters games (WMG) have more participants than any other international sporting competition and is under investigated, particularly with regard to indices of cardiovascular disease risk. Therefore, we chose to investigate selected cardiovascular risk factors in WMG participants. METHODS: This was a cross-sectional, observational study which utilized a web-based questionnaire to survey cardiovascular risk factors of WMG participants. The survey consisted of three sections: basic demographics, medical history and physiological parameters which included Body Mass Index (BMI), waist circumference (WC), resting blood pressure (BP) and lipids (total cholesterol [TC], high density lipoprotein [HDL] and low density lipoprotein [LDL]). RESULTS: A total of 1435 participants, 872 male, aged 27-91 years (mean age 54.99 years) participated in the study. Key findings included significant differences (P<0.05) between genders in BMI (17.7%, P<0.001), WC (10.6%, P<0.001), resting SBP (5.8%, P<0.001) and resting DBP (4.8%, P<0.001). Significant differences were also found between genders in HDLs (15.2%, P<0.001), TC:HDL ratio (17.2%, P<0.001) and LDL:HDL ratio (19.0%, P<0.001). Significant differences (P<0.001) were also identified when comparing WMG lipid results to the Australian general population (TC P<0.001; HDLs P<0.001; LDLs P<0.001). CONCLUSIONS: A high percentage of WMG participants demonstrated optimal values in a number of cardiovascular disease (CVD) risk factors when compared to the general population, female WMG participants had better values as compared to males. This reflected a decreased CVD in WMG participants and supports our hypothesis of enhanced health characteristics in an active, but aged cohort.

Hand Grip Strength and Gender: Allometric Normalization in Older Adults and Implications for the NIOSH Lifting Equation.

BACKGROUND: Many countries are experiencing an aging workforce with women workers making up a growing proportion. Workplaces often require employees to complete lifting tasks that require the ability of the hand to grasp an implement (coupling). The National Institute for Occupational Safety and Health (NIOSH) has developed an equation for manual lifting tasks hoping to minimize the potential for a workplace back-injury related to a lifting task. The NIOSH lifting equation relies upon stress variables including a coupling factor. However, little is known regarding grip strength as related to the NIOSH lifting equation coupling factor. The purpose of this study was to investigate differences in grip strength due to gender in older adults. METHODS: The participant's (68-88 years) maximal grip (MG) strength measures were collected for each hand with a hand grip dynamometer (kg). MG scores were converted to Newtons (N), normalized to body mass, and allometrically scaled. Measures of MG were than compared between genders with an independent t-test. RESULTS: The hand grip measures of MG (kg) [male: 30.3 ± 5.6, female: 10.6 ± 3.3], MG (kg) / body mass (kg) [male: 0.35 ± 0.06, female: 0.16 ± 0.04], MG (N) / (body mass (kg))0.67 [male: 15.1 ± 2.5, female: 6.2 ± 1.7], and MG (N) / (body height (m))1.84 [male: 103.6 ± 18.6, female: 42.6 ± 10.6] were all significantly lower (p < 0.0001) for women than men. Regardless of how grip strength was reported, there is a strong difference in grip strength between genders in this sample. The NIOSH lifting equation does not account for varying grip strength due to aging and gender differences. CONCLUSIONS: It is recommended that grip strength variability be accounted for in the coupling factor of the NIOSH lifting equation.

Optimal Timing for Post-Activation Potentiation in Women Collegiate Volleyball Players.

Post-activation potentiation (PAP) has been shown to acutely amplify muscular power output and may be advantageous for athletes looking to improve performance. PAP may have an acute window of effectiveness between 2 to 20 min. With correct timing and implementation it may be possible to induce PAP in competitive situations. The purpose of this study was to examine the time frame of potentiation following a PAP warm-up in collegiate female volleyball players. In this study, nine female collegiate volleyball players completed three laboratory sessions over the course of 10 days. During the first session, the athlete's 5-RM back squat was determined for subsequent use as the conditioning activity to initiate PAP. A repeated measures experimental design was then employed for Sessions 2 and 3 where half of the participants alternately performed either a dynamic or PAP warm-up prior to performing a standing long jump (SLJ) at 2, 6, 10, 14, and 18 min. A mixed-factor repeated measures ANOVA was used to determine the effects of the two warm-up strategies (PAP vs. dynamic) on standing long jump (SLJ) performance across time. There was a significant effect for time (p < 0.01) and warm-up strategy (p < 0.01). Bonferroni post hoc techniques determined that the SLJs that followed the PAP warm-up were significantly greater at 2 (4.8%), 6 (3.6%), and 10 (3.6%) min compared to SLJs post-dynamic warm-up (p < 0.05). However, those differences did not persist at 14 or 18 min (p > 0.05). Further analysis included non-parametric pairwise comparisons (Wilcoxon signed-rank tests) between the SLJ scores at 2, 6, 10, 14, and 18 min (PAP vs. dynamic). The non-parametric results were consistent with the parametric results. Within the parameters of this study, it is concluded that performing a 5-RM back squat induces a measureable PAP effect for up to 10 min.

Comparing one repetition maximum and three repetition maximum between conventional and eccentrically loaded deadlifts.

This study determined if an eccentrically loaded deadlift yields a higher 1 repetition maximum (1RM) and 3RM than a conventional deadlift and if the 1RM conventional and eccentrically loaded deadlift can be accurately estimated from the 3RM (3RM = 93% of 1RM). Division 1 football players (n = 15; 20.3 ± 1.9 years; 95.8 ± 18.2 kg; 184.4 ± 6.6 cm) participated. Deadlift 1RM and 3RM were measured in the conventional and eccentrically loaded deadlift. Dependent t-tests showed no significant difference between the 3RM and 1RM conventional deadlift and the 3RM and 1RM eccentrically loaded deadlift (p = 0.30 and p = 0.20, respectively). Pearson correlation between the 1RM conventional deadlift estimate and 1RM conventional deadlift actual was r = 0.91 (p ≤ 0.01); a dependent t-test indicated the 1RM conventional deadlift estimate was significantly less than the 1RM conventional deadlift actual (p = 0.007). Pearson correlation between the 1RM eccentrically loaded deadlift estimate and 1RM eccentrically loaded deadlift actual was r = 0.84 (p ≤ 0.01); a dependent t-test indicated the 1RM eccentrically loaded deadlift estimate was nearly significantly less than the 1RM eccentrically loaded deadlift actual (p = 0.061). Results suggest that conventional and eccentrically loaded deadlifts may be interchangeable within a training program; this may elicit the benefits of using a broader variety of ground-based multijoint compound movements in an athlete's strength and power training. Additionally, because of differences between predicted and actual 1RM scores in the deadlift, strength coaches should prioritize actual 1RM testing of their athletes to optimize deadlift training loads across the RM continuum.

Accuracy of Physical Self-Description Among Chronic Exercisers and Non-Exercisers.

This study addressed the role of chronic exercise to enhance physical self-description as measured by self-estimated percent body fat. Accuracy of physical self-description was determined in normal-weight, regularly exercising and non-exercising males with similar body mass index (BMI)'s and females with similar BMI's (n=42 males and 45 females of which 23 males and 23 females met criteria to be considered chronic exercisers). Statistical analyses were conducted to determine the degree of agreement between self-estimated percent body fat and actual laboratory measurements (hydrostatic weighing). Three statistical techniques were employed: Pearson correlation coefficients, Bland and Altman plots, and regression analysis. Agreement between measured and self-estimated percent body fat was superior for males and females who exercised chronically, compared to non-exercisers. The clinical implications are as follows. Satisfaction with one's body can be influenced by several factors, including self-perceived body composition. Dissatisfaction can contribute to maladaptive and destructive weight management behaviors. The present study suggests that regular exercise provides a basis for more positive weight management behaviors by enhancing the accuracy of self-assessed body composition.

The seated medicine ball throw as a test of upper body power in older adults.

Practitioners training the older adult may benefit from a low-cost, easy-to-administer field test of upper body power. This study evaluated validity and reliability of the seated medicine ball throw (SMBT) in older adults. Subjects (n = 33; age 72.4 ± 5.2 years) completed 6 trials of an SMBT in each of 2 testing days and 2 ball masses (1.5 and 3.0 kg). Subjects also completed 6 trials of an explosive push-up (EPU) on a force plate over 2 testing days. Validity was assessed via a Pearson Product-Moment correlation (PPM) between SMBT and EPU maximal vertical force. Reliability of the SMBT was determined using PPMs (r), Intraclass correlation (ICC, R) and Bland-Altman plots (BAPs). For validity, the association between the SMBT and the EPU revealed a PPM of r = 0.641 and r = 0.614 for the 1.5- and 3.0-kg medicine balls, respectively. Test-retest reliability of the 1.5- and 3.0-kg SMBT was r = 0.967 and r = 0.958, respectively. The ICC values of the 1.5- and 3.0-kg SMBT were R = 0.994 and 0.989, respectively. The BAPs revealed 94% of the differences between day 1 and 2 scores were within the 95% confidence interval of the mean difference. Test-retest reliability for the EPU was r = 0.944, R = 0.969. The BAPs showed 94% of the differences between day 1 and 2 scores were within the 95% confidence interval of the mean difference, for both medicine ball throws. In conclusion, for the older adult, the SMBT appears to be highly reliable test of upper body power. Its validity relative to the maximal force exerted during the EPU is modest. The SMBT is an inexpensive, safe, and repeatable measure of upper body power for the older adult.

Effect of functional isometric squats on vertical jump in trained and untrained men.

Functional isometrics (FIs) combine dynamic and isometric muscle actions and may hyperstimulate the nervous system leading to an enhanced postactivation potentiation (PAP) and improved subsequent performance. The purpose of this study was to investigate the impact of an FI squat on the countermovement vertical jump (CMVJ) in resistance trained and untrained men. Thirteen trained men (age: 22.8 +/- 3.2 years, mass: 90.0 +/- 16.3 kg, and height: 178.9 +/- 7.1 cm) and 8 untrained men (age: 28.5 +/- 5.9 years, mass: 101.5 +/- 23.0 kg, and height: 177.0 +/- 4.8 cm) participated. On separate days, subjects performed CMVJs after 2 different warm-up conditions. The warm-up conditions consisted of either 5 minutes of low-intensity cycling or 5 minutes of low-intensity cycling plus a 3-second FI squat with 150% of their 1 repetition maximum (1RM). A 2 x 3 repeated-measures analysis of variance with Bonferroni post hoc revealed that when comparing the 2 warm-up conditions in the trained subjects, a significant increase (p < 0.05) in CMVJ occurred at 4 minutes (2.4 cm, +5.1%) post-FI squat. This increase was maintained when subjects were retested at 5 minutes post (2.6 cm, + 5.5%). No significant difference in CMVJ was detected in the untrained group (p = 0.49). Results support the addition of an FI squat performed at 150% of 1RM to a low-intensity cycling warm-up to enhance PAP in resistance trained but not in untrained men as measured by CMVJ. Practically, adding functional isometrics to a warm-up scheme may significantly enhance acute, short-term power output in resistance trained men.

Physiological and psychophysical comparison between a lifting task with identical weight but different coupling factors.

The objective of the revised NIOSH (National Institute for Occupational Safety and Health) lifting equation is to prevent or reduce lifting-related injuries. The coupling component of the equation relates to quality of the grip (i.e., hand-to-object interface) and can be rated good, fair, or poor. Good coupling is theorized to reduce lifting stress, whereas poor coupling is theorized to increase lifting stress. This study compared the physiological and psychophysical stress between a lifting task with identical weight but different coupling factors. Subjects (n = 21; 26 +/- 6 years; 177.8 +/- 7.8 cm; 73.9 +/- 10.7 kg) transferred a milk crate or bag of dog food each weighing 12.5 kg back and forth from the floor to a table for 2, paced, 5-minute work bouts. Steady-state metabolic data were used to compare the lifting tasks. Results showed significantly higher oxygen consumption, caloric cost, heart rate, and rating of perceived exertion during the lifting task using the milk crate vs. the bag of dog food (p < 0.05). No difference in respiratory exchange ratio was observed (p > 0.05). In conclusion, a significantly higher metabolic cost and perceived exertion was observed when subjects performed a paced two-handed lifting task with good coupling factors than when using an object with poor coupling factors. When lifting stress is measured by metabolic cost and perceived exertion, these results are in contrast to expectations that a poor quality grip (i.e., poor coupling) would increase stress of a lifting task. Results of this study may help the work-place practitioner make decisions related to the use of the revised NIOSH lifting equation in the design and pacing of lifting-related tasks. Improved decision making may benefit productivity and enhance injury prevention in the workplace.

Anabolic androgenic steroids: use and perceived use in nonathlete college students.

OBJECTIVE: The authors investigated the use and perceived use of anabolic androgenic steroids (AAS) among nonathlete college students. PARTICIPANTS: The authors surveyed a sample of 485 nonathlete college students at a major metropolitan university. METHODS: They administered a survey on use and perceived use of AAS to the students. RESULTS: Forty-two participants (9%) reported using AAS (37 men, 5 women). Seniors were the most likely to use AAS (36%), and freshman the least likely (7%). Thirty-four percent of nonusers and 41% of users indicated they knew between 1 and 5 AAS users. Of the total sample, 36% perceived that 5% to 10% of nonathlete college students used AAS. Reasons for AAS use were because friends were using (7%), a desire to enhance physical appearance (45%), and a desire to increase physical performance (48%). CONCLUSIONS: These findings may have significant implications in planning strategic preventive educational programs, and health educators should target incoming college freshmen with the intent of dissuading AAS use.

Detraining in the older adult: effects of prior training intensity on strength retention.

In this study, we assessed the influence of training intensity on strength retention and loss incurred during detraining in older adults. In a previous study, untrained seniors (age = 71.0 +/- 5.0; n = 61) were randomly divided into 3 exercise groups and 1 control group. Exercise groups trained 2 days per week for 18 weeks with equivalent volumes and acute program variables but intensities of 2 x 15 repetitions maximum (RM), 3 x 9RM, or 4 x 6RM. Thirty of the original training subjects (age 71.5 +/- 5.2 years) participated in a 20-week detraining period. A 1RM for 8 exercises was obtained pre- and posttraining and at 6 and 20 weeks of detraining. The total of 1RM for the 8 exercises served as the dependent variable. Analysis of variance procedures demonstrated significant increases in strength with training (44-51%; p < 0.05), but no group effect. All training groups demonstrated significant strength decreases at both 6 and 20 weeks of detraining independent of prior training intensity (all group average 4.5% at 6 weeks and 13.5% at 20 weeks; p < 0.04). However, total-body strength was significantly greater than pretraining values after the detraining period (all group average 82% at 6 weeks and 49% at 20 weeks; p < 0.001). The results suggest that when older adults participate in progressive resistance exercise for 18 weeks, then stop resistance training (i.e., detrain), strength losses occur at both 6 and 20 weeks of detraining independent of prior resistance training intensity. However, despite the strength losses, significant levels of strength are retained even after 20 weeks of detraining. The results have important implications for resistance-trained older adults who could undergo planned or unplanned training interruptions of up to 5 months.