Acute effects of active warm-up and stretching on the flexibility of elderly women.

AIM: The purpose of the investigation was to examine the acute effects of static stretch on the range of motion (ROM) of the lower extremities and trunk in elderly women, when stretching is performed with and without warming-up exercises. METHODS: Twenty-two sedentary subjects 65-85 years old (mean age: 76.5 years) with normal ROM without joint abnormalities took part in the study, and performed 3 different flexibility protocols in non-consecutive randomized sessions. The first stretching protocol comprised of a general warming-up for 20 min, the second of the same general warming-up followed by static stretching of the lower extremities and the trunk, whereas the third and final stretching protocol consisted of static stretching alone. Passive ROM was examined at the lower extremity joints and trunk flexion, using a goniometer and a flexometer. RESULTS: Static stretching alone and static stretching after a general warming-up bout, significantly increased the range of all lower extremity joints and trunk flexion (P<0.001). The general warming-up session included a significantly increased ROM only at the ankle dorsiflexion joint (P<0.001). CONCLUSIONS: The results reflect immediate changes in flexibility via acute stretching exercises, in sedentary elderly women, when muscles undergo static elongation, irrespective of the performance of warming-up exercises.

Bilateral isokinetic peak torque of quadriceps and hamstring muscles in professional soccer players with dominance on one or both two sides.

AIM: Dominance of one leg may cause asymmetry between the contralateral muscle groups and develop predisposition for injury to the leg with the weaker muscle strength. The purpose of this study was to examine the strength balance in the extensor and flexor muscle groups, as well as the hamstring to quadriceps (H/Q) ratios of both legs in professional soccer players with dominance on one or both legs. METHODS: Forty-two professional soccer players of the first Greek division participated in this study. Participants were divided into 3 groups according to their leg use during training sessions and matches. Fifteen players comprised the first group with dominance to the right leg, 12 players formed the second group with dominance to the left leg, and 15 players consisted the third group with dominance to both the right and left legs. Maximum voluntary concentric torque of the hamstring and quadriceps muscles of both legs was assessed using a Norm isokinetic dynamometer at angular velocities of 12 degrees, 60 degrees, 180 degrees and 300 degrees/s. RESULTS: No significant differences in the strength balance found between the groups. The isokinetic variables comparing the right and left body side in each group, with dominance on one or both legs, did not differ. No differences were recorded in the H/Q between the right and left legs for any of the subject groups. CONCLUSIONS: There is no evidence of muscle imbalances in extensor and flexor muscle groups and H/Q ratios between the right and left legs in professional soccer players with dominance on one or both legs. The training sessions and matches appear to have imposed strength balance for the right and left body sides of professional soccer players.

The effect of active warm-up and stretching on the flexibility of adolescent soccer players.

AIM: The purpose of the investigation was to examine in field conditions the acute effects of passive stretching after a general warming-up bout as well as the effects of passive stretching alone. METHODS: Eighteen adolescent team soccer players participated in this study performing 3 different flexibility-training protocols in separate training sessions. In the first treatment stretching protocol a general warm-up was performed where subjects jogged for 20 minutes. The second treatment stretching protocol consisted of the same general warm-up followed by passive stretching of the lower extremities and the trunk, whereas the third and final treatment stretching protocol consisted of passive stretching alone, without any jogging. Passive range of joint motion was examined in hip flexion, hip extension, hip abduction, ankle dorsiflexion, knee flexion and trunk flexion using a goniometer and a flexometer. RESULTS: The general warming-up session induced a significantly increased range of motion only at the ankle dorsiflexion joint (P<0.05). Results also suggest that passive stretching alone and passive stretching after a general warming-up bout both induced a significantly increased range in all lower extremity joints and trunk flexion (P<0.001). CONCLUSIONS: Improvements in flexibility are observed after passive muscle elongation, irrespective of warming-up.

The effect of stretching during warming-up on the flexibility of junior handball players.

AIM: The purpose of the investigation was to examine in field conditions the acute effects of warming-up on lower extremity joints and trunk flexibility in junior team handball players. METHODS: Forty-seven junior team handball players participated in this study forming an experiment (n=32) and a control group (n=15). The first group performed warming-up and stretching exercises (20 min) whereas the second group only performed warming-up exercises. Passive range of joint motion was determined in hip flexion, hip extension, hip abduction, knee flexion, ankle dorsiflexion and the trunk flexion using a goniometer and a flexometer. RESULTS: The warming-up session induced a significantly increased range in all lower extremity joints and trunk flexion (p<0.01 to p<0.001) of both groups. CONCLUSION: Flexibility improves as a result of muscle elongation during warming-up or even through an incorporated pathetic stretching program.

Atrial natriuretic factor responses to submaximal and maximal exercise.

The aim of this study was to evaluate and compare the plasma concentration of atrial natriuretic factor (ANF), K+, Na+, blood lactate, heart rate, and blood pressure in moderately trained women. Ten healthy women were studied on a cycle ergometer during 20 min of constant submaximal and maximal exercise, as well as during recovery. The ANF concentration was determined by radioimmunoassay. The results show that, except for Na+, all the other variables increased significantly with an increase in the duration and intensity of the exercise (P < 0.05, P < 0.001). In recovery, the values fell (P < 0.01, P < 0.001). Submaximal and maximal exercise both cause increases in ANF and this increase is due to the duration and intensity of exercise. However, maximal exercise, rather than submaximal exercise, is the major stimulus for the concentration of plasma ANF. ANF concentration may be a useful test for evaluating the releasing function of ANF in the heart.

Peak torque of quadriceps and hamstring muscles in basketball and soccer players of different divisions.

Basketball and soccer are two games with different training and playing procedures. The purpose of this study was to examine the maximal voluntary peak torques of the quadriceps and hamstring muscles, and the torque ratio between these muscle groups in basketball players (n = 61) and soccer players (n = 51) participating in teams of different divisions. Isokinetic peak torques were measured using the Cybex II isokinetic dynamometer at 60 and 180 degrees.s-1. Basketball players of the national team produced higher peak torque values of quadriceps muscles than the other basketball players of different divisions (p < 0.05 to p < 0.001). Hamstring peak torques of the national basketball team were significantly higher the only velocities measured compared with the players from division II and IV (p < 0.05). Peak torque values of quadriceps muscles relative to body weight were significantly higher in the national basketball team compared with basketball players from division I. No significant differences were found in peak torque values of quadriceps and hamstring muscles within the different basketball and soccer divisions. Peak torque expressed in absolute terms was significantly higher in basketball players than in soccer players (p < 0.05 to p < 0.001). However, these differences were not significant when the strength of quadriceps and hamstring muscles was expressed relative to body weight. The H/Q ratio did not differ either ditto among the different divisions of basketball and soccer players. Based on the data obtained in this study, we concluded that the subjects' body weight have a decisive effect on the production of peak torque values of quadriceps and hamstring muscles in basketball and soccer players. Furthermore that the playing in different divisions, as well as participating in different sports, i.e. basketball or soccer, have surprisingly small effects on the peak isokinetic torque production of the quadriceps and hamstring muscles.