Steven E. Riechman

Children's OMNI scale of perceived exertion: mixed gender and race validation.

PURPOSE The newly developed Childrens OMNI Scale of Perceived Exertion (category range: 0 to 10) was validated using separate cohorts of female and male, African American and white subjects. Each of the four cohorts contained 20 clinically normal, nonobese children, 8-12 yr of age. METHODS A cross-sectional, perceptual estimation paradigm using a single multi-stage cycle ergometer test protocol was used. Oxygen uptake (VO2; mL x min(-1)), heart rate (HR; beats x min(-1)) and ratings of perceived exertion for the overall body (RPE-Overall), legs (RPE-Legs), and chest (RPE-Chest) were determined at the end of each continuously administered 3-min power output (PO) (i.e., 25, 50, 75, and 100 W) test stage. RESULTS The range of responses over the four POs for all cohorts was VO2: 290.8 to 1204.0 mL x min(-1); HR: 89.2 to 164.4 beats x min(-1); and RPE-Overall, RPE-Legs, and RPE-Chest: 0.85 to 9.1. First-order correlation and linear regression analyses were performed for each cohort separately and the total sample using a repeated measures paradigm over the four POs. For all correlation/regression paradigms RPE-Overall, RPE-Legs, and RPE-Chest distributed as a positive linear function of both VO2 and HR; r = 0.85 to 0.94; P < 0.01. Differences between RPE-Overall, RPE-Legs, and RPE-Chest were examined with ANOVA for the repeated measures paradigm. RPE-Legs was higher (P < 0.01) than RPE-Chest and RPE-Overall at 25, 50, 75, and 100 W. RPE-Chest did not differ from RPE-Overall at 25 and 50 W but was lower (P < 0.01) than RPE-Overall at 75 and 100 W. CONCLUSION The psycho-physiological responses provide validity evidence for use of the Childrens OMNI Scale over a wide range of dynamic exercise intensities.

Prediction of 2000 m indoor rowing performance using a 30 s sprint and maximal oxygen uptake

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 - 3.6 years, height 1.68 - 0.54 m, body mass 67.1 - 11.7 kg; mean - s ) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake ( V O 2 ) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest V O 2 measured during the test was recorded as V O 2max (mean = 3.18 - 0.35 l· min -1 ). Peak power (380 - 63.2 W) and mean power (368 - 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 - 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), V O 2max (l· min -1 ), V O 2max (ml·kg -1 ·min -1 ), V O 2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent V O 2max ) and V E max (l·min -1 ) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time 2000 =- 0.163 (Power)14.213 ·( V O 2max l· min -1 ) + 0.738· (Fatigue) + 567.259 ( R 2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while V O 2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.

Interleukin 6 Modulates lnterleukin-1– and Stress-Induced Activation of the Hypothalamic-Pituitary-Adrenal Axis in Male Rats

This study examined the interaction between interleukin 6 (IL-6) and IL-1 and between IL-6 and stress on the activation of the hypothalamic-pituitary-adrenal (HPA) axis. Coadministration of IL-6 (100 ng/rat) with IL-1 (20 or 100 mg/ rat) resulted in synergistic stimulation of the HPA axis, as determined by increased plasma levels of ACTH and corticosterone (CORT) which were greater in rats that received both cytokines than in rats receiving either cytokine alone. Concomitant administration of IL-6 (100 ng/rat) with exposure to a novelty stressor also synergistically stimulated the activation of the HPA axis, as IL-6-treated rats subjected to novelty stress had greater increases in plasma levels of ACTH and CORT than vehicle-treated rats exposed to novelty stress or rats receiving IL-6 alone. However, concomitant administration of IL-6 (100 ng/rat) did not significantly affect restraint stress induced elevation of plasma levels of ACTH and CORT, although IL-6 tended to prolong restraint stress induced elevation of plasma levels of CORT. These findings indicate a modulatory role for IL-6 stimulated HPA axis activity in response to IL-1 or a novelty psychological stressor, but not for restraint stress.

Strength tracking using the OMNI resistance exercise scale in older men and women.

Gearhart, RF Jr, Lagally, KM, Riechman, SE, Andrews, RD, and Robertson, RJ. Strength tracking using the OMNI resistance exercise scale in older men and women. J Strength Cond Res 23(3): 1011-1015, 2009-Strength tracking uses ratings of perceived exertion (RPE) as a reference value to determine changes in strength as a function of a resistance training program. The purpose of this investigation was to determine if the OMNI Resistance Exercise Scale (OMNI-RES) could be used to track training-induced strength changes in older adults. Twenty-two men (64.3 + 3.2 years) and 27 women (63.8 + 2.8 years) volunteered to participate. Subjects underwent a maximal lifting test, during which they estimated perceived exertion before and following 12 weeks of resistance exercise training. Leg press (LP), latissimus dorsi pull-down (LA), chest press (CP), leg extension (LE), leg curl (LC), arm extension (AE), and arm curl (AC) were performed. Paired samples t-tests were used to compare resistance lifted pre- and post-training at each criterion RPE (4, 6, and 8). One repetition maximum increased from pretraining to post-training (p < 0.05) for all exercises. The resistance lifted at each criterion RPE also increased (p < 0.05) during the 12-week training session for every exercise. Older adults lifted more weight at 3 criterion RPEs as their strength increased, providing an RPE-based procedure to track strength training changes using the OMNI-RES. As such, it seems that RPE from the OMNI-RES can be used to track strength in older adults.

IGF2 genotype and obesity in men and women across the adult age span

We studied a previously reported association between the IGF2 genes ApaI polymorphism and obesity in 500 healthy men and women (19–90 y). We hypothesized that individuals homozygous for the IGF2 A allele (A/A) would exhibit lower body mass, BMI and DEXA-measured fat mass compared to G/G homozygotes. Subjects were categorized as exhibiting the G/G (n=241), G/A (n=197) or A/A (n=62) genotype. Contrary to our hypothesis, no difference was observed in body mass, body mass index (BMI) or fat mass between the G/G and A/A genotype groups in the entire cohort. Surprisingly, Caucasian A/A individuals (n=427) exhibited significantly higher fat mass compared to Caucasian G/G individuals (P<0.05). In summary, individuals homozygous for the IGF2 G allele do not exhibit higher body mass, BMI or fat mass compared to A/A individuals; however, Caucasians with the A/A genotype exhibit higher fat mass than G/G individuals.

Acute resistance exercise augments integrative myofibrillar protein synthesis

The purpose of this study was to determine whether an acute bout of high-intensity resistance exercise (RE) would augment integrative mixed muscle and myofibrillar protein fractional synthesis rates (FSRs) when total energy and macronutrient intake was controlled. Twelve healthy young men were studied over 24 hours and performed an acute bout of exhaustive (5 sets until volitional failure of their 85% 1-repetition maximum) unilateral leg press and knee extension exercise, such that one leg was exercised (EX) and the other served as a control (CON). (2)H(2)O (70%) was provided to measure mixed muscle and myofibrillar FSR, and muscle biopsies (vastus lateralis) were collected from the EX and CON legs 16 hours following the RE session. (2)H-labeling of body water over the course of the experiment was 0.32 ± 0.01 mole percent excess. Interestingly, integrative mixed muscle FSR (percent per hour) was similar between the CON (0.76% ± 0.08%) and EX (0.69% ± 0.06%) legs. In contrast, upon determination of myofibrillar FSR, there was an RE effect (EX, 0.94% ± 0.16% vs CON, 0.75% ± 0.08%; P < .05). High-intensity RE without prior training impacts integrative myofibrillar 24-hour FSR, perhaps without altering total responses.

Regulators of blood lipids and lipoproteins? PPARδ and AMPK, induced by exercise, are correlated with lipids and lipoproteins in overweight/obese men and women

PPARδ is a transcription factor regulating the expression of genes involved in oxidative metabolism, which may regulate blood cholesterols through transcription of oxidative and lipoprotein metabolism genes. To determine the association of skeletal muscle PPARδ content with blood lipids and lipoproteins before and following exercise, overweight and obese men (n = 9) and women (n = 7) were recruited; age, BMI, body fat percentage, and Vo(2max) were (means ± SE) 45 ± 2.5 yr, 31.9 ± 1.4 kg/m(-2), 41.1 ± 1.5%, and 26.0 ± 1.3 mLO(2)·kg(-1)·min(-1), respectively. Subjects performed 12 wk of endurance exercise training (3 sessions/wk, progressing to 500 kcal/session). To assess the acute exercise response, subjects performed a single exercise session on a treadmill (70% Vo(2max), 400 kcal energy expenditure) before and after training. Muscle and blood samples were obtained prior to any exercise and 24 h after each acute exercise session. Muscle was analyzed for protein content of PPARδ, PPARα, PGC-1α, AMPKα, and the oxidative and lipoprotein markers FAT/CD36, CPT I, COX-IV, LPL, F(1) ATPase, ABCAI, and LDL receptor. Blood was assessed for lipids and lipoproteins. Repeated-measures ANOVA revealed no influence of sex on measured outcomes. PPARδ, PGC-1α, FAT/CD36, and LPL content were enhanced following acute exercise, whereas PPARα, AMPKα, CPT I, and COX-IV content were enhanced only after exercise training. PPARδ content negatively correlated with total and LDL cholesterol concentrations primarily in the untrained condition (r ≤ -0.4946, P < 0.05), whereas AMPKα was positively correlated with HDL cholesterol concentrations regardless of exercise (r ≥ 0.5543, P < 0.05). Our findings demonstrate exercise-induced expression of skeletal muscle PPARs and their target proteins, and this expression is associated with improved blood lipids and lipoproteins in obese adults.

Effect of a conditioned aversive stimulus on the immune response in three strains of rats

In the present study we investigated the effect of a brief exposure (15 s) to a conditioned aversive stimulus (CS) on the proliferative response of spleen and peripheral blood lymphocytes (PBL) in Lewis, Fischer 344 and Sprague-Dawley rats. Plasma levels of ACTH and corticosterone were also measured. For conditioning, rats were exposed to 10 presentations of a 5 s duration foot-shock (1.6 mA) preceded by a 15 s tone. Seven days later, animals were exposed to the auditory signal without electric shock. Significant differences were found in both the kinetics and the magnitude of altered mitogenic responsiveness of PBL between the different strains of rats. Enhancement of PBL responsiveness to mitogens was observed in Fischer and Sprague-Dawley rats immediately after exposure to the CS. A significant decrease in the response of PBL to mitogens was found in Lewis and Sprague-Dawley rats 10 min after exposure to the CS. The PBL response of Sprague-Dawley and Fischer rats returned to baseline at 30 min, but not in Lewis rats. Proliferative activity of spleen lymphocytes in response to the CS was suppressed from baseline in all rat strains, but the timing and degree of suppression differed. Fischer rats had the largest percentage of suppression. The earliest suppression of spleen mitogenic function after exposure to the CS was in Fischer rats, while the Lewis rats had the latest onset of suppression, with the Sprague-Dawley rats being intermediate. Plasma levels of ACTH and corticosterone peaked at 10 min in all strains of rats. The magnitude of hormonal elevation differed in the different rat strains, suggesting that corticosterone may not have a variable immunomodulatory role in each strain. These data suggest that a brief psychological stressor results in activation of the HPA axis and is associated with strain-dependent alterations of lymphocyte responsiveness to non-specific mitogens. The short-term exposure to a CS which produces different parameters of lymphocyte functional modulation, provides a useful tool to study the mechanisms of stressor-induced immune alteration.

Greater gains in strength and power with intraset rest intervals in hypertrophic training.

Abstract Oliver, JM, Jagim, AR, Sanchez, AC, Mardock, MA, Kelly, KA, Meredith, HJ, Smith, GL, Greenwood, M, Parker, JL, Riechman, SE, Fluckey, JD, Crouse, SF, and Kreider, RB. Greater gains in strength and power with intraset rest intervals in hypertrophic training. J Strength Cond Res 27(11): 3116–3131, 2013—We sought to determine if hypertrophic training with intraset rest intervals (ISRs) produced greater gains in power compared with traditional rest (TRD) hypertrophic training. Twenty-two men (age 25 ± 5 years, height 179.71 ± 5.04 cm, weight 82.1 ± 10.6 kg, 6.5 ± 4.5 years of training) matched according to baseline characteristics were assigned to 12 weeks of training using TRD or ISR. Body composition, strength (1-repetition maximum [1RM] bench and squat), and power output (60% 1RM bench and squat, and vertical jump) were assessed at baseline, 4, 8, and 12 weeks. Determination of myosin heavy chain (MHC) percentage from the vastus lateralis was performed pretraining and posttraining. Body composition was analyzed by analysis of variance, whereas performance measures and MHC were analyzed by analysis of covariance with baseline values as the covariate. Data are presented as mean ± SD changes pre to post. The ISR produced greater power output in bench (TRD 32.8 ± 53.4 W; ISR 83.0 ± 49.9 W, p = 0.020) and vertical jump (TRD 91.6 ± 59.8 W; ISR 147.7 ± 52.0 W; p = 0.036) with squat power approaching significance (TRD 204.9 ± 70.2 W; ISR 282.1 ± 104.2 W; p = 0.053) after post hoc analysis (p < 0.10). The ISR produced greater gains in bench (TRD 9.1 ± 3.7 kg; ISR 15.1 ± 8.3 kg; p = 0.010) and squat (TRD 48.5 ± 17.4 kg; ISR 63.8 ± 12.0 kg; p = 0.002) strength. Both protocols produced significant gains in lean mass with no significant differences between groups (1.6 ± 2.1 kg; p = 0.869). The MHCIIx percentage decreased (−31.0 ± 24.5%; p = 0.001), whereas the MHCIIA percentage increased (28.9 ± 28.5%; p = 0.001) with no significant differences between groups. Results indicate that hypertrophy training with ISR produces greater gains in strength and power, with similar gains in lean mass and MHC alterations as TRD. The ISR may be best used in hypertrophic training for strength and power sports.

Cumulative responses of muscle protein synthesis are augmented with chronic resistance exercise training.

Aim:  The purpose of this study was to determine the anabolic response of a single bout of high intensity resistance exercise (RE) following 5 weeks of RE training.