Practical blood flow restriction training is a new training technique that has the potential to increase muscular hypertrophy and muscular strength while allowing practitioners to train with lighter loads (20-30% of 1-RM). Through the use of elastic knee wraps, the limbs can be restricted using a perceived pressure scale. The comparison of practical blood flow resistance training with traditional, non-blood flow restricted resistance training and its effects on muscular hypertrophy and strength has not been investigated. Twenty-one resistance-trained males participated in a 4-week training program and were randomly assigned to one of two groups: Practical BFR training (BFR; n = 10) and Resistance training (RT; n = 11). The primary difference between the groups was the BFR group performed approximately 62% of all sets blood flow restricted at 20-30% of 1-RM while the RT group performed all sets at an intensity of > 70% 1-RM in a traditional manner (non-blood flow restricted). Perceived pressure for blood flow restriction in the BFR group for the arms and legs was 7 out of 10. Workouts for both groups were similar and consisted of whole body routines ~3 days/week. A 2x2 repeated measures ANOVA was used to assess group, time, and group by time interactions. Statistical significance was set to p ≤ 0.05. There was a no difference in total lifting volume with the BFR group achieving a total lifting volume that was 11% less than the RT group. There was a main effect for time for biceps cross-sectional area (p = 0.004), thigh girth (p = 0.002), bench press 1RM (p = 0.001) and leg press 1RM (p < 0.001). Specifically, BFR improved from 220.5 ± 65.1 to 235.0 ± 50.6 pounds and from 822 ± 135.9 to 952.5 ± 168.9 pounds in the bench press and leg press, respectively. The RT improved from 245.9 ± 60.9 to 257.7 ± 53.5 pounds and from 780.5 ± 192.4 to 957.3 ± 213.4 pounds in the bench press and leg press, respectively. No interaction effects were observed for all hypertrophy and strength variables. 4-weeks of practical blood flow restriction training is as effective for inducing maximal bench press and leg press strength, as well as biceps muscle size and thigh muscle size, as compared to traditional resistance training, despite training at low percentages of subjects 1-RM.

The human immunodeficiency virus (HIV)-1 can compromise pulmonary function at all stages of the disease. The present study examined whether there were differences in resting and exercising pulmonary function among sedentary, resistance-trained and aerobically-trained, early symptomatic, HIV-1+ men. Forty five subjects, 15 per group, were enrolled. An analysis of variance (ANOVA) showed differences in demographics for age [F (2, 42) = 5.14, p<0.01)], weight [F (2, 42) = 4.84, p<0.01)], body mass index [F (2, 42) = 9.50, p<0.01)] and average years HIV-1+ [F (2, 42) = 4.78, p<0.01)]. A multiple analysis of covariance (MANCOVA) showed differences in resting pulmonary function [F (8, 72) = 7.164, P = 0.01]. Univariate ANOVA's and Bonferroni post-hoc comparisons showed the aerobically-trained group had higher forced expiratory volume in one second (FEV1) than the resistance-trained and sedentary groups (p<0.05 and p<0.01, respectively), higher forced vital capacity (FVC) (p<0.01, for both), higher maximum voluntary ventilation (p<0.01, for both) and higher FEV1/FVC ratios than the sedentary group only (p<0.01). The resistance-trained group also showed higher FEV1 (p<0.01) and FEV1/FVC (p<0.01) than the sedentary group. For exercising pulmonary function, significant differences in our MANCOVA were found [F (12, 68) = 12.73, P = 0.001]. Univariate ANOVA's and Bonferroni post-hoc comparisons showed that the aerobically-trained group had higher dyspnea index than the resistance-trained and sedentary groups (p<0.01 and p<0.05, respectively), higher ventilatory efficiency (RR/VE max) than the resistance-trained and sedentary groups (p<0.05 and p<0.01, respectively), higher maximum minute ventilation (VE max) (p<0.01, for both), higher peak oxygen consumption (peak VO2) (p<0.01, for both) and lower dead space (VD/VT) (p<0.01, for both). The resistance-trained group also showed higher peak VO2 (p<0.01), lower VD/VT (p<0.01) and lower RR/VE max (p<0.01) than the sedentary group. Results suggest that aerobically-trained, and to a lesser extent, resistance-trained seropositives possessed superior resting and exercising pulmonary function compared to sedentary seropositive males.

Cross-education of strength is a neural adaptation defined as the increase in strength of the untrained contralateral limb after unilateral training of the opposite homologous limb. The neural mechanisms of the effect have remained elusive, although it appears to be a motor learning adaptation. Despite cross-education of strength being an inter-limb effect, no previous study has determined the influence of handedness and the direction of transfer (dominant to non-dominant or the reverse). Arguably, this is partly responsible for massive variation in the literature regarding the magnitude of the effect. The primary purpose of this document is to attempt to determine the central and peripheral neuro-physiological mechanisms controlling cross-education of muscular strength. Prior to determining the mechanisms of the effect, the influence of handedness and the preferred direction of transfer for cross-education of strength must be addressed. The secondary purpose is to determine the preferential direction of transfer of cross-education of strength in order to isolate the circumstances in which the effect is more pronounced. Two experiments were necessary to meet these objectives. <p>Experiment 1: The purpose was to determine the effect of the direction of transfer on cross-education in right-handed individuals. Subjects were randomized into a left-hand training (LEFT), right-hand training (RIGHT), or non-training control (CON) group. Strength training was 6 weeks of maximal isometric ulnar deviation, 4 times per week. The change in strength in the untrained limb was greatest in the RIGHT group (39.2%; p<.01), whereas no significant changes in strength were observed for the untrained limb of the LEFT group (9.3%) or for either of the CON group limbs (10.4% and 12.2%). There were no changes in muscle thickness of untrained limbs compared to CON. Changes in untrained limb EMG were not different compared to CON. Cross-education with hand strength training occurs only in the right-to-left direction of transfer in right-handed individuals. Cross-education of arm muscular strength is most pronounced to the non-dominant arm. <p>Experiment 2: The purpose of this study was to determine the central and peripheral mechanisms of cross-education of strength after actual and imagery training. Subjects were randomized into an actual training, imagery training, or non-training control group. A sub-sample of 8 subjects (4 actual, 4 imagery training) had brain activity during exercise assessed with functional magnetic resonance imaging (fMRI). Strength training was 6 weeks of maximal isometric handgrip ulnar deviation (Biodex) of the right arm, 4 times per week. Actual training was highly effective for increasing strength in trained (45.3%; p<.01) and untrained (47.1%; p<.01) limbs. Imagery training and control groups had no increases in strength for either arm. Muscle thickness increased only in the trained arm of the actual group (8.4%; p<.001). After actual training, there was an increase in activation of contralateral sensorimotor cortex and left temporal lobe during actual contractions with the untrained left arm (p<.001). Actual training was associated with a significantly greater change in agonist muscle activation pooled over both limbs, compared to the imagery and control groups (p<.05). Cross-education of strength is only significant after actual training, indicating that peripheral feedback is necessary for the effect. Cross-education of strength is accompanied by changes in cortical activation indicative of motor learning and the retrieval of memory of movement acquired by the trained limb. <p>General Conclusion: The neuro-physiological mechanism of cross-education of strength is that changes in cortical activation indicative of motor learning occur in both brain hemispheres after unilateral training. Cross-education of strength is influenced by strength asymmetries related to handedness, and the preferential direction of transfer is from dominant to non-dominant limb. Cross-education is a motor learning adaptation also reliant on peripheral feedback during training.

The 'repeated bout effect'(RBE) is an adaptation whereby a single eccentric (ECC) exercise session protects against muscle damage during subsequent ECC exercise bouts and is characterized by faster strength recovery and a reduction in soreness and inflammation. The purpose was to determine if the protective capacity of the RBE is greater when both bouts of ECC exercise are performed at the same compared to a different velocity of contraction as well as at a fast or slow velocity. Thirty-one right handed participants were randomly assigned to perform an initial unilateral bout of either fast (180°/s) or slow (30°/s) maximal isokinetic ECC elbow flexion. Three weeks later 16 participants completed a repeated bout of ECC exercise at the same velocity as the initial bout (SAME)(FAST-FAST[n=8] and SLOW-SLOW[n=8]), while 15 participants completed a bout at the corresponding different velocity (DIFF) (FAST-SLOW[n=8] and SLOW-FAST[n=7]). Elbow flexor function and damage was measured prior to, immediately after, and at 24, 48, and 72 hours post exercise. Dependant variables included maximal voluntary contraction (MVC) isometric strength (Dynamometer), muscle thickness (MT; Ultrasound), delayed onset muscle soreness (DOMS; Visual Analog Scale), biceps and triceps electromyography (EMG), percent activation (Interpolated twitch), and twitch torque. There were no group differences for height, weight, training experience, or total work performed during the ECC bouts (p>0.05). After the repeated bout, there was a significant reduction in MVC strength, MT, and DOMS at 24, 48, and 72 hours, pooled across participants (p<0.05). After the repeated bout, MVC strength recovered faster only for the SAME group. There were no differences between groups for MT, DOMS, EMG, ITT, and TT. The analysis revealed neither fast nor slow contractions offered greater protection against muscle damage when the repeated bout was not completed at the same velocity. Since a faster recovery of strength is velocity specific this suggests there may be a neural contribution to the repeated bout effect.

The 'repeated bout effect'(RBE) is an adaptation whereby a single eccentric (ECC) exercise session protects against muscle damage during subsequent ECC exercise bouts and is characterized by faster strength recovery and a reduction in soreness and inflammation. The purpose was to determine if the protective capacity of the RBE is greater when both bouts of ECC exercise are performed at the same compared to a different velocity of contraction as well as at a fast or slow velocity. Thirty-one right handed participants were randomly assigned to perform an initial unilateral bout of either fast (180°/s) or slow (30°/s) maximal isokinetic ECC elbow flexion. Three weeks later 16 participants completed a repeated bout of ECC exercise at the same velocity as the initial bout (SAME)(FAST-FAST[n=8] and SLOW-SLOW[n=8]), while 15 participants completed a bout at the corresponding different velocity (DIFF) (FAST-SLOW[n=8] and SLOW-FAST[n=7]). Elbow flexor function and damage was measured prior to, immediately after, and at 24, 48, and 72 hours post exercise. Dependant variables included maximal voluntary contraction (MVC) isometric strength (Dynamometer), muscle thickness (MT; Ultrasound), delayed onset muscle soreness (DOMS; Visual Analog Scale), biceps and triceps electromyography (EMG), percent activation (Interpolated twitch), and twitch torque. There were no group differences for height, weight, training experience, or total work performed during the ECC bouts (p>0.05). After the repeated bout, there was a significant reduction in MVC strength, MT, and DOMS at 24, 48, and 72 hours, pooled across participants (p<0.05). After the repeated bout, MVC strength recovered faster only for the SAME group. There were no differences between groups for MT, DOMS, EMG, ITT, and TT. The analysis revealed neither fast nor slow contractions offered greater protection against muscle damage when the repeated bout was not completed at the same velocity. Since a faster recovery of strength is velocity specific this suggests there may be a neural contribution to the repeated bout effect.

Cross-education of strength is a neural adaptation defined as the increase in strength of the untrained contralateral limb after unilateral training of the opposite homologous limb. The neural mechanisms of the effect have remained elusive, although it appears to be a motor learning adaptation. Despite cross-education of strength being an inter-limb effect, no previous study has determined the influence of handedness and the direction of transfer (dominant to non-dominant or the reverse). Arguably, this is partly responsible for massive variation in the literature regarding the magnitude of the effect. The primary purpose of this document is to attempt to determine the central and peripheral neuro-physiological mechanisms controlling cross-education of muscular strength. Prior to determining the mechanisms of the effect, the influence of handedness and the preferred direction of transfer for cross-education of strength must be addressed. The secondary purpose is to determine the preferential direction of transfer of cross-education of strength in order to isolate the circumstances in which the effect is more pronounced. Two experiments were necessary to meet these objectives. <p>Experiment 1: The purpose was to determine the effect of the direction of transfer on cross-education in right-handed individuals. Subjects were randomized into a left-hand training (LEFT), right-hand training (RIGHT), or non-training control (CON) group. Strength training was 6 weeks of maximal isometric ulnar deviation, 4 times per week. The change in strength in the untrained limb was greatest in the RIGHT group (39.2%; p<.01), whereas no significant changes in strength were observed for the untrained limb of the LEFT group (9.3%) or for either of the CON group limbs (10.4% and 12.2%). There were no changes in muscle thickness of untrained limbs compared to CON. Changes in untrained limb EMG were not different compared to CON. Cross-education with hand strength training occurs only in the right-to-left direction of transfer in right-handed individuals. Cross-education of arm muscular strength is most pronounced to the non-dominant arm. <p>Experiment 2: The purpose of this study was to determine the central and peripheral mechanisms of cross-education of strength after actual and imagery training. Subjects were randomized into an actual training, imagery training, or non-training control group. A sub-sample of 8 subjects (4 actual, 4 imagery training) had brain activity during exercise assessed with functional magnetic resonance imaging (fMRI). Strength training was 6 weeks of maximal isometric handgrip ulnar deviation (Biodex) of the right arm, 4 times per week. Actual training was highly effective for increasing strength in trained (45.3%; p<.01) and untrained (47.1%; p<.01) limbs. Imagery training and control groups had no increases in strength for either arm. Muscle thickness increased only in the trained arm of the actual group (8.4%; p<.001). After actual training, there was an increase in activation of contralateral sensorimotor cortex and left temporal lobe during actual contractions with the untrained left arm (p<.001). Actual training was associated with a significantly greater change in agonist muscle activation pooled over both limbs, compared to the imagery and control groups (p<.05). Cross-education of strength is only significant after actual training, indicating that peripheral feedback is necessary for the effect. Cross-education of strength is accompanied by changes in cortical activation indicative of motor learning and the retrieval of memory of movement acquired by the trained limb. <p>General Conclusion: The neuro-physiological mechanism of cross-education of strength is that changes in cortical activation indicative of motor learning occur in both brain hemispheres after unilateral training. Cross-education of strength is influenced by strength asymmetries related to handedness, and the preferential direction of transfer is from dominant to non-dominant limb. Cross-education is a motor learning adaptation also reliant on peripheral feedback during training.

In this study it has been investigated what is missing in non-strength training women to begin exercise regular strength training. It has also examined the level of knowledge about the health benefits and the employer's encouragement to maintain good health. The study was designed in a qualitative methodology and data collection was designed in form of semi-structured interviews. Six women were interviewed between the ages 22-51år. The results showed that women possessed a very low level of knowledge about strength training and also fears and prejudices existed among them. It also showed that the employers encouraging to them to be concerned about his health did not exist beyond that some of them had access to health care contributions. The results also showed that few of them were interested to start strength training as a preventive measure, but only on their backs would be too bad or a strong weight gain would occur. / I denna studie har det undersökts vad som saknas hos icke-styrketränande kvinnor för att de ska börja med regelbunden styrketräning. Det har även undersökt hur kunskapsnivån kring hälsofrämjande effekter och arbetsgivarens uppmuntran sett ut. Studien utformades efter kvalitativ metod och datainsamlingen skedde i form av semistrukturerade intervjuer. Sex kvinnor intervjuades i åldrarna 22-51år. Resultaten visade att kvinnorna besatt en väldigt låg grad av kunskap kring styrketräning och att tydliga rädslor och fördomar fanns bland dem. Det framgick även att arbetsgivarnas uppmuntran till att de skulle vara måna om sin hälsa inte existerade utöver att några av dem hade tillgång till friskvårdsbidrag. I resultaten visades även att få av dem var intresserade att börja styrketräna i förebyggande syfte utan endast om deras ryggar skulle bli för dåliga eller en kraftig viktuppgång skulle ske.

THW

Introduction and Purpose: In chronic heart failure (CHF), exercise rehabilitation results in a reduced risk of mortality, decreased disease severity, and increased functional ability. Resistance training is an important component of cardiac rehabilitation; however, an optimal training velocity that produces physiological and functional benefits at minimal perceived exertion and cardiovascular stress has yet to be identified. CHF patients need to be very efficient and perform the exercise that will give them the greatest benefits because of their poor exercise tolerance and increased risk of cardiovascular complications during exercise. In older populations, high velocity resistance training results in greater improvements in functional ability than low velocity resistance training. The use of high velocity resistance training in patients with CHF has yet to be examined; however it may enhance higher velocity activities of daily living while using a lower training load. The lower load associated with high velocity training may be less strenuous and result in lower cardiovascular stress, whilst maintaining a relatively similar power output compared to traditional low-velocity training. The purpose of this study was to compare the acute cardiovascular responses and perceived exertion of high and low velocity resistance exercises. Methods and Measures: 6 male and 1 female patients with systolic heart failure (CHF NYHA Class I-III) were recruited to perform two separate, randomly assigned exercise sessions. These sessions consisted of 5 exercises (hack squat, chest press, knee flexion, lat pull down and knee extension); one with a low velocity of contraction (3 second concentric phase: 3 second eccentric phase at 50% of the slow velocity 1-RM) and one with a high velocity (1 second concentric phase: 3 second eccentric phase at 50% of the high velocity 1-RM). During both sessions, heart rate, blood pressure, and a rating of perceived exertion (RPE) were obtained after the completion of each exercise. Results: Despite a similar relative mechanical load, the high velocity workout produced significantly lower systolic blood pressure (121.2 vs. 132.8 mmHg), mean arterial pressure (87.8 vs. 93.5), and RPE (3.7 vs.4.8) than the low velocity workout (p<0.05). The high velocity workout was not significantly different from the low velocity workout for heart rate, rate pressure product and diastolic blood pressure. Conclusion: We conclude that the high velocity workout produces more favourable blood pressure responses to resistance training in patients with CHF than the low velocity workout and may be used to enhance functional outcomes in cardiac rehabilitation programs.

The purpose was to determine the velocity during strength and power training, with elastic resistance bands, in older adults. Nine older patients, who attended the day hospital rehabilitation program at Riverview Health Centre, were trained for power and strength of the ankle muscles using elastic resistance bands for 4 to 6 weeks. Training sessions were filmed to assess the velocity of training using Proanalyst software. Power training occurred at faster peak velocities as compared to strength training (p<0.001) for both muscle groups, however there were significant differences for average velocity only during training of plantar flexors (p<0.001). There was no significant difference between strength and power training in terms of within individual variability. However, a wide variability was observed between subjects in velocities they trained at and overlap was found between velocities for strength and power training. Hence, researchers should monitor velocity during different types of training in older adults.