Active warm-up and time-of-day effects on repeated-sprint performance and post-exercise recovery.

PURPOSE: This study investigated the effects of both an active warm-up and the time-of-day variation on repeated-sprint performance. A second objective was to compare the post-exercise recovery between the experimental conditions. METHODS: Eleven male participants performed ten maximal cycling sprints (6 s each, with a 30-s interval between them) in the morning and late afternoon, either after a warm-up or control condition. The warm-up consisted of cycling for 10 min at 50% of the peak aerobic power. RESULTS: Rest measurements of rectal, muscle, and skin temperatures were higher in the afternoon compared to the morning (p < 0.05), with no significant differences in heart rate (p = 0.079) and blood lactate concentration (p = 0.300). Warm-up increased muscle temperature, heart rate, and lactate, and reduced skin temperature (all p < 0.001), though no significant differences were observed for rectal temperature (p = 0.410). The number of revolutions (p = 0.034, ηp2 = 0.375), peak (p = 0.034, ηp2 = 0.375), and mean (p = 0.037, ηp2 = 0.365) power of the first sprint (not the average of ten sprints) were higher in the afternoon compared to the morning, regardless of warm-up. However, beneficial performance effects of warming up were evident for the first (p < 0.001) and the average of ten sprints (p < 0.05), regardless of time of day. More remarkable changes during the 60-min post-exercise were observed for rectal temperature (p = 0.005) and heart rate (p = 0.010) in the afternoon than in the morning. CONCLUSION: Warming-up and time-of-day effects in enhancing muscular power are independent. Although warm-up ensured further beneficial effects on performance than the time-of-day variation, a faster post-exercise recovery was observed in the late afternoon.

Central blood pressure and aortic pulse wave reflection in water-exercised postmenopausal hypertensive women: A cross-sectional study.

Exercise training has been associated with the attenuation of cardiovascular impairment after menopause. This study aimed to compare central and peripheral blood pressure and aortic pulse wave reflection in sedentary and trained (aerobic exercise in the water) hypertensive postmenopausal women. Hypertensive postmenopausal women were divided into sedentary (SED, n = 53) and trained groups (TR, n = 31). Self-reporting from the trained group presented a mean of 1.7 ± 0.3 years of exercise practice in the water. Central blood pressure and amplification indexes (AIx) were obtained by the applanation tonometry of radial and aortic arteries. No changes were observed in systolic blood pressure (SBP) in the TR group than the SED group; however, office diastolic blood pressure (DBP) was reduced compared to the SED group. Central blood pressure and augmentation index (AIx@75%) values were similar in the SED and TR groups. These data suggest that self-reported long-term exercise training in the water could not improve central hemodynamic variables in postmenopausal hypertensive women compared to sedentary ones. However, it should be emphasized that DBP levels were reduced in trained subjects, which might reduce cardiovascular outcomes.

Chitosan gels for buccal delivery of Schinus molle L. essential oil in dogs: characterization and antimicrobial activity in vitro.

Periodontal disease is considered the main oral cavity disorder in dogs. Essential oils have the potential for use in the prevention and treatment of oral diseases. The antimicrobial activity of Schinus molle L. essential oil (SMEO) has already been reported. Chitosan, a natural product with antimicrobial activity and good biocompatibility has potential in biodental applications. In this study, we evaluated the in vitro antimicrobial activity of SMEO against bacteria associated with periodontal disease in dogs, developed and evaluated the physicochemical properties of a novel chitosan-based buccal delivery system containing SMEO. SMEO showed antimicrobial activity against Gram positive and Gram negative bacteria associated with canine periodontitis, with MIC values of 750 µg.mL-1 for Staphylococcus spp. and Streptococcus spp, 1000 µg.mL-1 for Corynebacterium spp. and 1250 µg.mL-1 for Pseudomonas spp. All formulations evaluated presented adequate physicochemical properties, good stability, and pH values close to buccal pH (5.0-7.0). Chitosan gel loaded with SMEO showed potential as a SMEO delivery system, having the ideal physicochemical and rheological properties (pseudoplastic and apparent viscosities) required for application on buccal tissue. Thus, we can conclude that formulation has the potential to be used for buccal mucosa delivery in the prevention and treatment of periodontal disease in dogs.

Can low-level laser therapy when associated to exercise decrease adipocyte area?

Obesity affects approximately 20% of the world population, and exercise is the primary non-pharmacological therapy. The combined use of exercise and low-level laser therapy (LLLT) may potentiate the effects promoted by exercise. The objective of this study was to investigate the effects of exercise in combination with phototherapy on adipocyte area, activity of the enzyme citrate synthase and muscle morphological analysis. We used 64 Wistar rats, which were divided into eight groups with 8 rats each: sedentary chow-diet (SC); sedentary chow-diet plus laser therapy (SCL), exercised chow-diet (EC); exercised chow-diet plus laser therapy (ECL); sedentary high-fat diet (SH); sedentary high-fat diet plus laser therapy (SHL); exercised high-fat diet (EH); exercised high-fat diet, laser therapy (EHL). The animals were submitted to a program of swimming training for 90min/5 times per week for 8weeks and LLLT (GA-Al-AS, 830nm) at a dose of 4.7J/point and a total energy of 9.4J/animal, with duration of 47s, which was applied to both gastrocnemius muscles after exercise. We conclude that the combined use of exercise and phototherapy increases the activity of the enzyme citrate synthase and decreases the white adipocyte area epididymal, retroperitoneal and visceral in obese rats, enhancing the effects of exercise.

High analgesic and anti-inflammatory in vivo activities of six new hybrids NSAIAs tetrahydropyran derivatives.

We present in this article syntheses of six new hybrids compounds (4-9) that were efficiently prepared in one or two steps (70-84.6%) from our previous prototype (±)-cis-4-chloro-6-(naphthalen-1-yl)-tetrahydro-2H-pyran-2-yl)methanol (3) and the NSAIAs: acetyl salicylic acid, indomethacin, ibuprofen, ketoprofen, naproxen and diclofenac. The acetic acid-induced writhing method is able to determine that all investigated new hybrids showed stronger antinociceptive properties (2- to 10-fold less ED50 values) than their precursors. The highest antinociceptive effect was observed for compound 9 showing more than 10-fold less ED50 values than diclofenac and ninefold less ED50 value than compound 2. All compounds presented greater activity than the control group in the tail-flick test confirming the central antinociceptive effect. New hybrids did not alter the motor performance of mice by rota-rod performance and open-field tests. Investigated compounds 4-9 were not toxic after oral administration (LD50 >2000mg/kg).

Amphetamine- and nicotine-induced cross-sensitization in adolescent rats persists until adulthood.

Nicotine and psychostimulants are often abused in combination and drug abuse often begins during adolescence and can have long-term consequences. Behavioral sensitization has been suggested as an animal model of neuroplasticity implicated in the development of drug addiction. We evaluated whether the pretreatment with nicotine (0.4 mg/kg; s.c.) or amphetamine (5.0 mg/kg; i.p.) in adolescent rats [from postnatal day (P) 28 to P34] could induce cross-sensitization to nicotine and amphetamine when animals were challenged during both adolescence (P37) and adulthood (P70), in separate groups of animals. Adolescent animals pretreated with amphetamine displayed behavioral sensitization to nicotine, which persisted until adulthood. Moreover, adolescent animals pretreated with nicotine showed sensitized locomotor response to amphetamine in the adulthood. These data suggest that adolescents who abuse nicotine may be particularly susceptible to the effects of amphetamine and vice versa. Moreover, this increased vulnerability may persist through their development until adulthood.