Joseph F. Signorile

Physical and psychological changes with vigorous exercise in sedentary primigravidae

PURPOSE The present study examined the effects of exercise on physical and psychological variables in sedentary primigravidae (PRA). METHODS A total of nine women randomly assigned to an exercise (E) (mean age = 31.3 +/- 3.1 yr) and six subjects randomly assigned to a control (C) group (mean age = 27.8 +/- 3.1 yr) fulfilled all requirements for the study. Exercise included a variety of exercise activities performed to a target heart rate of 150-156 beats x min(-1), three times per week for 15 wk. RESULTS Results showed no significant differences between E and C groups in physical characteristics initially. A repeated measures ANOVA showed a significant group effect (P < 0.05) and a significant group by time interaction (P = 0.001) with the E group showing a significantly longer amount of time on the PWC150 test than the C group. There was no significant group, time, or group by time interaction for lactate accumulation. This occurred, despite the fact that the E group spent 56% longer on the PWC150 test and the C group spent 30% less time on the same test at the conclusion of the study. Finally, the E group in comparison to the C group showed more favorable improvements in several items related to health and well-being on the Body Cathexis Scale. There were no significant differences between E and C groups in any pregnancy outcome measures. All babies were delivered healthy at term. CONCLUSIONS These data suggest that a vigorous exercise program can lead to significant improvements in aerobic fitness at similar lactate concentrations compared to a control group and can be well tolerated by low risk sedentary PRA without any deleterious effects occurring to herself or unborn child.

The effects of albuterol and isokinetic exercise on the quadriceps muscle group.

Subjects performed 9 wk of isokinetic knee extensions twice weekly. Albuterol (N = 13) or placebo (N = 9) was administered for 6 wk; groups received 16 mg.d-1 of either treatment. Training consisted of three sets of 10 repetitions at 45 degrees.s-1. Data were collected at weeks 0, 6, and 9. Concentric and eccentric variables examined included: peak torque (CPT, EPT), total work (CTW, ETW), average power (CAP, EAP), time to peak torque (CTTPT, ETTPT), peak torque to body weight ratio (CPT/BW), and work to body weight ratio (CW/BW, EW/BW). Other variables included: thigh circumference (CIRC), thigh cross-sectional area (CSA), forced vital capacity (FVC), and forced expiratory volume (FEV1), MANOVA and the Dunn-Bonferroni post-hoc found differences within groups for CPT, CTW, CAP, CPR/BW, EPT, ETTPT, and CSA. Interactions were noted for CW/BW, ETW, EAP, EPT/BW, and ETW/BW; with persons administered albuterol yielding superior values. CW/BW, ETW, and EAP showed interactions at post-testing, while EPT/BW and EW/BW interacted at both midtesting and post-testing. Results indicate therapeutic doses of albuterol administered with resistance exercise may augment strength gains.

Optimal Frequency, Displacement, Duration, and Recovery Patterns to Maximize Power Output Following Acute Whole-Body Vibration

Adams, JB, Edwards, D, Serviette, D, Bedient, AM, Huntsman, E, Jacobs, KA, Del Rossi, G, Roos, BA, and Signorile, JF. Optimal frequency, displacement, duration, and recovery patterns to maximize power output following acute whole-body vibration. J Strength Cond Res 23(1): 237-245, 2009-Power is an important component of general health, fitness, and athletic performance. Traditional overload techniques require considerable time, intensity, and volume of training. Whole-body vibration (WBV) is a potentially less time-consuming method for increasing power performance than traditional training. However, the exact protocols that can maximize power output have not yet been identified. Eleven healthy men, aged 32.3 ± 4.1 years, and 9 healthy women, aged 29.1 ± 3.5 years, performed countermovement jumps (CMJs) of maximal volition to assess peak power pre and post (immediately and at 1, 5, and 10 minutes) randomized WBV stimuli set at different frequency (30, 35, 40, and 50 Hz), displacement (2-4 vs. 4-6 mm), and duration (30, 45, and 60 seconds) combinations. Repeated-measures analysis of variance on peak power normalized to initial power (nPP) revealed no significant effects attributable to duration of stimulus. However, high frequencies were more effective when combined with high displacements, and low frequencies were more effective in conjunction with low displacements (p < 0.05). Additionally, the greatest improvements in nPP occurred at 1 minute posttreatment, with significant improvements lasting through 5 minutes posttreatment (p < 0.05). Optimal acute effects can be attained using as little as 30 seconds of WBV, and they are highest from 1 to 5 minutes posttreatment. Additionally, high frequencies were most effective when applied in conjunction with high displacements, whereas low frequencies were most effective when applied in conjunction with low displacements.

Comparison of MRI with EMG to study muscle activity associated with dynamic plantar flexion

This study compared magnetic resonance imaging (MRI) and surface electromyography (EMG) to evaluate the effect of knee angle upon plantar flexion activity in the triceps surae muscles [medial & lateral gastrocnemius (MG, LG) and the soleus (SOL)]. Two weight & height matched groups performed identical protocols, twelve (6M, 6F) in the MRI group, twelve (8M, 4F) in the EMG group. Subjects plantar flexed dynamically for 2 min at 25% of 1-repetition maximum voluntary contraction (1-RM). Exercise was performed with the knee extended (0 degrees flexion), flexed (90 degrees ), and partially flexed (45 degrees ). In the MRI group spin-echo images were acquired before and immediately following each exercise session. T(2) times, calculated at rest and after exercise by fitting the echoes to a monoexponential decay pattern with a least-squares algorithm, were compared with EMG data. In the EMG group a bipolar electrode was used to collect samples were from the MG, LG, SOL, and anterior tibialis (TA) during exercise at each knee angle, MRI also examined the peroneus (PER). At 0 degrees flexion MRI demonstrated a significant post-exercise T(2) increase in the MG (p < or = 0.001), LG (p < or = 0.001), and PER (p < or = 0.01), with no T(2) change in the SOL or TA. At 90 degrees flexion there was a significant T(2) increase in the SOL (p < or = 0.001) with no significant T(2) change in the MG, LG, PER, or TA. At 45 degrees T(2) increased significantly in the SOL (p < or = 0.001) and LG (p < or = 0.05), but not the MG, PER, or TA. EMG produced similar results with the exception that there was significant activity in the TA during the relaxation cycle of the 90 degrees protocol. We conclude that: 1) Soleus activity is measurable by MRI; and 2) MRI and EMG produce similar results from different physiological sources, and are therefore complementary tools for evaluating muscle activity.

A Comparative Electromyographical Investigation of Muscle Utilization Patterns Using Various Hand Positions During the Lat Pull-down

This study aimed at investigating the effects of different hand positions on the electromyographic (EMG) activity of shoulder muscles during the performance of the lat pulldown exercise. Ten healthy men performed 3 repetitions of the lat pull-down exercise using their experimentally determined 10RM (repetition maximum) weight. Four different common variations of the lat pull-down were used: close grip (CG), supinated grip (SG), wide grip anterior (WGA), and wide grip posterior (WGP). Normalized root mean square of the EMG (NrmsEMG) activity for the right posterior deltoid (PD), latissimus dorsi (LD), pectoralis major (PM), teres major (TM), and long head of the triceps (TLH) were recorded using surface electrodes and normalized using maximum voluntary contractions. Repeated measures analysis of variance for each muscle detected statistical differences (p < 0.05) in myoelectric activity among hand positions during both the concentric and eccentric phases of the exercise. During the concentric phase, NrmsEMG results for the LD included WGA > WGP, SG, CG. For the TLH: WGA > WGP, SG, CG and WGP > CG, SG. For the PD: CG, WGA, SG > WGP. For the PM: CG, WGA, SG > WGP. During the eccentric phase, the LD produced the following patterns: WGA > WGP, SG, CG and WGP > CG. The TLH pattern showed WGA > SG and CG. For the PD: CG > WGA, WGP. The results indicate that changes in handgrip position affect the activities of specific muscles during the lat pull-down movement. Also, performance of the lat pulldown exercise using the WGA hand position produces greater muscle activity in the LD than any other hand position during both the concentric or eccentric phases of the movement.

Caffeine, maximal power output and fatigue.

The purpose of this investigation was to determine the effects of caffeine ingestion on maximal power output and fatigue during short term, high intensity exercise. Nine adult males performed 15 s maximal exercise bouts 60 min after ingestion of caffeine (7 mg.kg-1) or placebo. Exercise bouts were carried out on a modified cycle ergometer which allowed power output to be computed for each one-half pedal stroke via microcomputer. Peak power output under caffeine conditions was not significantly different from that obtained following placebo ingestion. Similarly, time to peak power, total work, power fatigue index and power fatigue rate did not differ significantly between caffeine and placebo conditions. These results suggest that caffeine ingestion does not increase ones maximal ability to generate power. Further, caffeine does not alter the rate or magnitude of fatigue during high intensity, dynamic exercise.

Effects of acute inhalation of the bronchodilator, albuterol, on power output

This study was designed to examine the effects of acute inhalation of the bronchodilator, albuterol (Proventil, Schering Corp.), on high intensity power output. Fifteen healthy nonasthmatic subjects (eight male, seven female, 18-33 yr) performed four supramaximal 15-s rides on a bicycle ergometer. Rides were arranged in pairs with a 10-min rest interval. Each pair of rides was preceded by a 5-min warm-up. Sessions were separated by a minimum of 48 h. The study design was fully randomized and double blind. Ten minutes prior to each pair of rides subjects inhaled two metered doses (180 micrograms) of albuterol (A) or a placebo (P). Individual ANOVAs revealed a significant difference between the A and P treatment for peak power (A = 886.6 W, P = 858.3 W) and fatigue (A = 27.2%, P = 24.4%). Mean changes in FEF25-75% (A = 0.712, P = 0.040 l.s-1), FEV1.0 (A = 0.188, P = 0.007 l), and PEF (A = 0.573, P = -0.155 l.s-1) were also statistically significant; however, these changes did not correlate to the anaerobic performance changes. No significant differences were found between treatments for heart rate increases resulting from the power test (A = 56.73 bpm, P = 53.20 bpm). These results indicate an ergogenic effect of the bronchodilator on short-term power output independent of impact on respiratory smooth muscle, with no effect on cardiac response.

Pilot Study Comparing Changes in Postural Control After Training Using a Video Game Balance Board Program and 2 Standard Activity-Based Balance Intervention Programs

OBJECTIVE To compare the impacts of Tai Chi, a standard balance exercise program, and a video game balance board program on postural control and perceived falls risk. DESIGN Randomized controlled trial. SETTING Research laboratory. PARTICIPANTS Independent seniors (N=40; 72.5±8.40) began the training, 27 completed. INTERVENTIONS Tai Chi, a standard balance exercise program, and a video game balance board program. MAIN OUTCOME MEASURES The following were used as measures: Timed Up & Go, One-Leg Stance, functional reach, Tinetti Performance Oriented Mobility Assessment, force plate center of pressure (COP) and time to boundary, dynamic posturography (DP), Falls Risk for Older People-Community Setting, and Falls Efficacy Scale. RESULTS No significant differences were seen between groups for any outcome measures at baseline, nor were significant time or group × time differences for any field test or questionnaire. No group × time differences were seen for any COP measures; however, significant time differences were seen for total COP, 3 of 4 anterior/posterior displacement and both velocity, and 1 displacement and 1 velocity medial/lateral measure across time for the entire sample. For DP, significant improvements in the overall score (dynamic movement analysis score), and in 2 of the 3 linear and angular measures were seen for the sample. CONCLUSIONS The video game balance board program, which can be performed at home, was as effective as Tai Chi and the standard balance exercise program in improving postural control and balance dictated by the force plate postural sway and DP measures. This finding may have implications for exercise adherence because the at-home nature of the intervention eliminates many obstacles to exercise training.

Displacement and frequency for maximizing power output resulting from a bout of whole-body vibration.

Bedient, AM, Adams, JB, Edwards, DA, Serravite, DH, Huntsman, E, Mow, SE, Roos, BA, and Signorile, JF. Displacement and frequency for maximizing power output resulting from a bout of whole-body vibration. J Strength Cond Res 23(6): 1683-1687, 2009-Whole-body vibration (WBV) has been shown to be effective for increasing lower-body power; however, the combination of frequency, displacement, and duration that elicits the best acute response has yet to be determined. The purpose of this study was to identify the protocol eliciting the greatest improvement in power after an acute bout of WBV. Forty men and women participated in this study, in which 8 different combinations of 30, 35, 40, and 50 Hz with 2-mm and 5-mm displacements were tested over 3 days. For all protocols, randomized to reduce potential order effects, subjects underwent 30 seconds of WBV while holding an isometric squat at a knee angle of 2.27 rad. Power was assessed by countermovement jumps. Subjects performed 3 jumps before WBV, immediately afterward, and 1, 5, and 10 minutes later. The highest normalized peak power (nPP) at each time point was determined using a 4 (frequency) × 2 (displacement) × 5 (time) repeated-measures analysis of variance. Significant effects were seen for frequency (p ≤ 0.026) and time (p ≤ .0001). Post hoc analyses revealed that the 30-Hz condition (1.010 ± 0.003) produced a higher nPP than 35 Hz (1.00 ± 0.003, p ≤ 0.026) and 40 Hz (1.002 ± 0.002, p ≤ 0.028) but not 50 Hz (1.004 ± .002). We also found a significantly higher nPP for the 1-minute post-treatment time point (1.011 ± .0003) vs. all other time points (p ≤ 0.006). Our data show that an acute WBV bout can significantly increase power output at 1 minute post-treatment across all frequencies and displacements, although 30 Hz appears to have a greater effect on power output than either 35 Hz or 40 Hz, but not 50 Hz, at all post-treatment time points.

Increased muscle strength in paralyzed patients after spinal cord injury: Effect of beta-2 adrenergic agonist

The administration of beta-2 adrenergic agonists in experimental animals result in an increased strength of skeletal muscle. In this study, we evaluated whether a beta-2 adrenergic agonist, metaproterenol, had an effect on muscle size and strength in a group of patients with muscular atrophy following spinal cord injury. Ten male subjects were randomly divided into 2 groups and agreed to participate in a prospective, double-blind, placebo-controlled, and crossover study. Metaproterenol (80 mg/day), or placebo, was administered orally for a period of 4 weeks. Muscle strength was measured by a force transducer interfaced with a microcomputer. Muscle size was calculated and expressed as a cross-sectional area of upper arm and forearm using a formula. Metaproterenol induced a significant increase of muscle strength in both groups of subjects, compared with placebo (p < .001). Similarly, there was an increase in a muscle size in the forearm following the administration of metaproterenol. Our data indicate that beta-2 adrenergic agonists may improve both muscle strength and size in patients with muscular atrophy following spinal cord paralysis.