Electromyographic activity of rectus abdominis muscles during dynamic Pilates abdominal exercises.

OBJECTIVE: To assess the electrical behaviour of the upper rectus abdominis (URA) and lower rectus abdominis (LRA) by electromyography (EMG) during the following dynamic Pilates abdominal exercises: roll up, double leg stretch, coordination, crisscross and foot work. The results were compared with EMG findings of traditional abdominal exercises (sit up and crunch). METHODS: Seventeen female subjects (with no experience of the Pilates method) were recruited. The URA and LRA were evaluated while 12 isotonic contractions were performed using the Pilates principles or traditional abdominal exercises. The data were normalised by a maximal voluntary isometric contraction. Normality was accepted, and ANOVA followed by Tukey test was used to determine data differences (P < 0.05). RESULTS: Pilates exercises double leg stretch, coordination, crisscross and foot work promoted greater muscle activation than traditional exercises, mainly in URA. Thus, these exercises have the potential to be prescribed for muscle strengthening programmes.

Acute cardiovascular responses while playing virtual games simulated by Nintendo Wii(®).

[Purpose] This investigation evaluated the acute cardiovascular responses that occur while playing virtual games (aerobic and balance) emulated by Nintendo Wii(®). [Subjects] Nineteen healthy male volunteers were recruited. [Methods] The ergospirometric variables of maximum oxygen consumption, metabolic equivalents, and heart rate were obtained during the aerobic (Obstacle Course, Hula Hoop, and Free Run) and balance (Soccer Heading, Penguin Slide, and Table Tilt) games of Wii Fit Plus(®) software. To access and analyze the ergospirometric information, a VO2000 analyzer was used. Normalized data (using maximum oxygen consumption and heart rate) were analyzed using repeated measures analysis of variance and Scheffe's test. [Results] Significant differences were found among the balance and aerobic games in all variables analyzed. In addition, the Wii exercises performed were considered to be of light (balance games) and moderate (aerobic games) intensity in accordance with American College Sports Medicine exercise stratification. [Conclusion] Physical activity in a virtual environment emulated by Nintendo Wii(®) can change acute cardiovascular responses, primarily when Wii aerobic games are performed. These results support the use of the Nintendo Wii(®) in physical activity programs.

Cardiovascular effects of Zumba(®) performed in a virtual environment using XBOX Kinect.

[Purpose] This study evaluated the acute cardiovascular responses during a session of Zumba(®) Fitness in a virtual reality environment. [Subjects] Eighteen healthy volunteers were recruited. [Methods] The following cardiovascular variables: heart rate, systolic blood pressure, diastolic blood pressure, and double product were assessed before and after the practice of virtual Zumba(®), which was performed as a continuous sequence of five choreographed movements lasting for 22 min. The game Zumba Fitness Core(®), with the Kinect-based virtual reality system for the XBOX 360, was used to create the virtual environment. Comparisons were made among mean delta values (delta=post-Zumba(®) minus pre-Zumba(®) values) for systolic and diastolic blood pressure, heart rate, and double product using Student's t-test for paired samples. [Results] After a single session, a significant increase was noted in all the analyzed parameters (Systolic blood pressure=18%; Diastolic blood pressure=13%; Heart rate=67%; and Double product=97%). [Conclusion] The results support the feasibility of the use of Zumba Fitness Core(®) with the Kinect-based virtual reality system for the XBOX 360 in physical activity programs and further favor its indication for this purpose.

Effects of low-level laser therapy (LLLT) on bone repair in rats: optical densitometry analysis.

The aim of this study was to evaluate the process of bone repair in rats submitted to low-level laser therapy using optical densitometry. A total of 45 rats which underwent femoral osteotomy were randomly distributed into three groups: control (group I) and laser-treated groups using wavelengths in the red (λ, 660-690 nm) and in the infrared (λ, 790-830 nm) spectra (group II and group III, respectively). The animals (five per group) were killed after 7, 14, and 21 days and the femurs were removed for optical densitometry analysis. Optical density showed a significant increase in the degree of mineralization (gray level) in both groups treated with the laser after 7 days. After 14 days, only the group treated with laser therapy in the infrared spectrum showed higher bone density. No differences were observed between groups after 21 days. Such results suggest the positive effect of low-level laser therapy in bone repair is time- and wavelength-dependent. In addition, our results have confirmed that optical densitometry technique can measure bone mineralization status.

Detection of creatine in rat muscle by FTIR spectroscopy.

There is a current lack of clarity regarding the use of Fourier-transform infrared spectroscopy (FT-IR) to evaluate intramuscular concentrations of creatine (Cr). Thus, the aim of this study was to assess the FT-IR spectral features of tibialis anterior muscle in rats submitted in conditions that were expected to perturb the Cr pool. First, an experiment was performed to ensure that FT-IR was able to detect the Cr intramuscular in sedentary and supplemented rats (Experiment 1). The effect of physical exercise on spectral muscle features was then examined, especially in relation to the spectroscopy markers (Experiment 2). Using pure Cr (control), it was possible to verify that only the peaks centered at 1308 and 1396 cm(-1) of all the spectra showed the same peak positions, indicating these FT-IR shifts as indirect markers of Cr intramuscular content. Experiment 2 revealed a higher Cr content for the Cr-supplemented and exercised animals than the rats of other groups. In conclusion, it was demonstrated that FT-IR spectroscopy using 1396 cm(-1) and mainly 1308 band was able to monitor Cr muscle content in rats sedentary, Cr-supplemented, and submitted to physical training. Besides, FT-IR could be a feasible method for the nondestructive assessment of Cr skeletal muscle content.

Influence of creatine supplementation on bone quality in the ovariectomized rat model: an FT-Raman spectroscopy study.

The influence of creatine (Cr) supplementation on cortical and trabecular bone from ovariectomized rats was studied using FT-Raman spectroscopy. The intensity of organic-phase Raman bands was compared to mineral phase ones. Twenty-one female Wistar rats aged 3 months were divided into three groups (n = 7 per group): ovariectomized (OVX), ovariectomized treated with creatine (CRE) and sham-operated (SHAM) groups. Creatine supplementation (300 mg kg(-1) day(-1)) was provided for 8 weeks, starting 12 weeks after ovariectomy. FT-Raman spectroscopy was performed on the right medial femoral mid-shaft (cortical bone) and third lumbar vertebral body (trabecular bone). The integrated intensities of mineral phase (phosphate and carbonate bands at 959 and 1,071 cm(-1), respectively) and organic phase (amide I band at 1,665 cm(-1)) Raman bands were analyzed. The mineral-to-matrix (phosphate/amide I), carbonate-to-phosphate, and carbonate-to-amide I ratios were analyzed to assess bone quality. The phosphate content on trabecular bone was higher in the CRE group than the OVX group (p < 0.05). No significant changes in mineral or organic phases on cortical bone were observed. A radiographic assessment of bone density was encouraging as the same findings were showed by Raman intensity of phosphate from cortical (r(2) = 0.8037) and trabecular bones (r(2) = 0.915). Severe ovariectomy-induced bone loss was confirmed by FT-Raman spectroscopy. The results suggest that the chemical composition of trabecular bone tissue may be positively influenced by Cr supplementation after ovariectomy.

Effects of different swimming exercise intensities on bone tissue composition in mice: a Raman spectroscopy study.

OBJECTIVE: Raman spectroscopy was employed to evaluate the effect of different swimming intensities on femoral bone composition in an animal model. BACKGROUND DATA: Intense swimming exercise may affect bone mineralization, and Raman technique has been shown to be effective in evaluating tissue composition (phosphate minerals and carbonate apatites - bands at 960 and 1170 cm(-1), as well as collagen matrix - amide I band at 1660 cm(-1)). MATERIALS AND METHODS: Eighteen female Swiss Webster mice were separated into three groups (n = 6 per group) of sedentary (SED), and swimming with an intensity of 40% (PT-40) and 80% (PT-80) of the maximum load, with 6 weeks of training. Near-infrared Raman spectra (830 nm wavelength and 80 mW laser power) were obtained with a dispersive Raman spectrometer using a CCD camera and imaging spectrograph with 30-s integration time. Spectra were collected in the medial and lateral diaphysis of the femur and principal components analysis (PCA) was employed to extract features of the Raman bands of bone and to perform quantitative analysis. RESULTS: PC1 vector resembles Raman spectra and carries information about apatite minerals and some contribution from organic matrix. A statistically significant difference was found in the PC1 scores (ANOVA, p < 0.05), indicating lower mineral concentrations in the femur in both the PT-40 and PT-80 groups compared to the SED group. These results corroborated with the radiographic assessment of bone density. CONCLUSION: Raman technique associated with PCA statistics showed that intense swimming exercise may affect bone mineralization and remodeling in a mouse model of training.