Vanessa Batista da Costa Santos

Análise comparativa do equilíbrio unipodal de atletas de ginástica rítmica

ABSTRACT Introduction: Rhythmic gymnastics requires a high level of physical quality; therefore, good performance depends on muscular strength and endurance, motor coordination and postural balance. Objective: To develop a comparative analysis of postural balance in rhythmic gymnasts. Methods: 10 female rhythmic gymnasts were evaluated by a force platform on one foot and balance functional tests (Side Hop Test and Figure of Eight Hop Test). The following data of the force platform were analyzed: anteroposterior and mediolateral of the center of pressure parameters, while for the functional tests, the time in seconds was analyzed. Results: Significant difference (p = 0.01) was found between lower limbs in the median frequency parameter in the mediolateral direction, in which non dominant lower limb showed higher postural stability than the dominant one. For functional tests, there was no significant difference between limbs. Conclusion: The difference found in the balance control of mediolateral direction may be related to different muscular actions of the hip region, which is present during the sport practice for stabilization, trunk maintenance, and movement performance with lower limbs. These results indicate the need of a balance program and pelvic sta-bilization for the analyzed athletes in order to maintain muscular symmetry of the limbs for high sports performance.Keywords: postural balance, athletes, sports.

Effects of chronic caffeine intake and low‐intensity exercise on skeletal muscle of Wistar rats

Caffeine can affect muscle cell physiology and the inflammatory response during exercise. The purpose of this study was to analyse muscle damage markers and inflammatory cell infiltration into the soleus muscle of sedentary and exercised animals submitted to chronic caffeine intake. Thirty‐two male Wistar rats were divided into the following four groups (n= 8 per group): sedentary control (SCO); sedentary + caffeine (SCAF); trained control (TCO); and trained + caffeine (TCAF). The animals were housed in individual cages and received tap water or caffeine (1 mg ml−1); they were maintained at rest or submitted to swimming for up to 40 min day−1 with a 4% load, five times per week for 30 days. Blood samples were collected for analysis of serum lactate, creatine kinase and calcium. The right soleus muscle and the epididymal fat depot were weighed, and the muscle was submitted to histological analysis. Training and caffeine did not change body or muscle weight, food and liquid intake or serum calcium levels among groups. Decreased fat tissue (P < 0.05) was observed in the SCAF (4.05 ± 1.03 g), TCO (4.14 ± 0.78 g) and TCAF groups (4.02 ± 1.02 g) compared with the SCO group (5.31 ± 1.06 g). Serum creatine kinase activity was significantly reduced in the SCAF (787.3 ± 230.3 U l−1), TCO (775.3 ± 232.3 U l−1) and TCAF groups (379.5 ± 110.5 U l−1) compared with the SCO group (1610.2 ± 276.5 U l−1). Few damaged muscle fibres (P < 0.05) were found in SCAF (16.7 ± 12.8%) and TCAF groups (17.3 ± 11.7%) compared with the SCO group (53.6 ± 13.9%). The SCAF group presented fewer fields with inflammatory cells (7.6 ± 8.7 fields) compared with the SCO group (123 ± 146 fields). The results suggest that the chronic intake of caffeine, as well as chronic low‐intensity exercise, decreased muscle damage and inflammatory infiltration into skeletal muscle.

Efeito do treinamento físico e da ingestão crônica de cafeína sobre o tecido ósseo de ratos jovens

Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.

Effect of cryotherapy on the ankle temperature in athletes: ice pack and cold water immersion

Introduction Cryotherapy is often used for rehabilitation of injured athletes. Objective To compare the effectiveness of ice pack (IP) and cold water immersion (CWI) on lowering the ankle skin surface temperature in athletes. Materials and methods Thirteen athletes (seven women and six men), age 19.53 (± 2.9) years. IP and CWI were applied on the anterior talofibular ligament (ATFL) of the dominant leg for 30 minutes. The skin surface temperature was measured with an infrared digital thermometer prior to the application and during cryotherapy (10, 15, 20, 25 and 30 minutes) and up to two hours of rewarming. During rewarming, the athletes remained at rest and the temperature was measured every 1 minute until 10 minutes, every 5 minutes for up to an hour and every 15 minutes until 2 hours. Results The two types of cold application were effective in lowering the skin surface temperature after the 30-minute procedure. Significant differences were observed among the following temperatures: pre-application (IP = 29.8 ± 2.4 °C and CWI = 27.5 ± 3 °C – P < 0.05); after 30 minutes (IP = 5 ± 2.4 °C and CWI = 7.8 ± 3 °C – P < 0.01). For rewarming, after 25 minutes (IP = 20.8 ± 3.3 °C and CWI = 18.2 ± 2.7 °C – P < 0.04); after 45 minutes (IP = 24.5 ± 2.3 °C and IP = 22.1 ± 3.5 °C – P < 0.05); after 75 minutes (IP = 26.4 ± 2.2 °C and CWI = 24 ± 2.7 °C – P < 0.02). Conclusion After the 30-minute application, both IP and CWI produced the appropriate temperature; however the application of CWI produced the lowest temperature during rewarming.

Effect of exercise training and chronic caffeine intake on bone tissue of young rats

Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.

Efecto del entrenamiento físico y la ingestión crónica de cafeína sobre El hueso de ratas jóvenes

Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.Effects of swimming training and chronic caffeine intake on bone tissue of young rats were investigated. Young Wistar rats were allocated into 4 groups: sedentary control (SCO), sedentary + caffeine (SCAF), trained (TCO) and trained + caffeine (TCAF); they received 1 mg/ml of caffeine diluted in water for 30 days (SCAF and TCAF) and were submitted to swimming training of moderate intensity for 21 days (TCO and TCAF). The left tibia was subjected to the biomechanical test for determination of the coefficient of stiffness, yield and maximum load. The immature bone tissue area and thickness of growth plates were evaluated in the femur. No changes were observed in biomechanical properties and the area occupied by immature bone tissue. However, SCAF group presented greater thickness in distal growth plate. The results suggest that the moderate intensity swimming training and caffeine consumption were not able to promote changes in morphology and biomechanical properties of bone tissue.