Potential Energy as an Alternative for Assessing Lower Limb Peak Power in Children: A Bayesian Hierarchical Analysis.

The aim of this study was to analyze the use of potential energy (PE) as an alternative method to assess peak power of the lower limbs (PP) in children. 815 Spanish children (416 girls; 6-11 years old; Body Mass Index groups (n): underweight = 40, normal weight = 431, overweight = 216, obese = 128) were involved in this study. All participants performed a Countermovement Jump (CMJ) test. PP was calculated using Duncan (PPDUNCAN), Gomez-Bruton (PPGOMEZ) and PECMJ formulas. A model with PECMJ as the predictor variable showed a higher predictive accuracy with PPDUNCAN and PPGOMEZ than CMJ height (R2 = 0.99 and 0.97, respectively; ELPDdiff = 1037.0 and 646.7, respectively). Moreover, PECMJ showed a higher linear association with PPDUNCAN and PPGOMEZ across BMI groups than CMJ height (ßPECMJ range from 0.67 to 0.77 predicting PPDUNCAN; and from 0.90 to 1.13 predicting PPGOMEZ). Our results provide further support for proposing PECMJ as an index to measure PP of the lower limbs, taking into account the children's weight and not only the height of the jump. Therefore, we suggest the use of PECMJ in physical education classes as a valid method for estimating PP among children when laboratory methods are not feasible.

Effects of a Rehabilitation Programme Using a Nasal Inspiratory Restriction Device in COPD.

Chronic obstructive pulmonary disease (COPD) patients are characterised for presenting dyspnea, which reduces their physical capacity and tolerance to physical exercise. The aim of this study was to analyse the effects of adding a Feel-Breathe (FB) device for inspiratory muscle training (IMT) to an 8-week pulmonary rehabilitation programme. Twenty patients were randomised into three groups: breathing with FB (FBG), oronasal breathing without FB (ONBG) and control group (CG). FBG and ONBG carried out the same training programme with resistance, strength and respiratory exercises for 8 weeks. CG did not perform any pulmonary rehabilitation programme. Regarding intra group differences in the value obtained in the post-training test at the time when the maximum value in the pre-training test was obtained (PostPRE), FBG obtained lower values in oxygen consumption (VO2, mean = -435.6 mL/min, Bayes Factor (BF10) > 100), minute ventilation (VE, -8.5 L/min, BF10 = 25), respiratory rate (RR, -3.3 breaths/min, BF10 = 2), heart rate (HR, -13.7 beats/min, BF10 > 100) and carbon dioxide production (VCO2, -183.0 L/min, BF10 = 50), and a greater value in expiratory time (Tex, 0.22 s, BF10 = 12.5). At the maximum value recorded in the post-training test (PostFINAL), FBG showed higher values in the total time of the test (Tt, 4.3 min, BF10 = 50) and respiratory exchange rate (RER, 0.05, BF10 = 1.3). Regarding inter group differences at PrePOST, FBG obtained a greater negative increment than ONBG in the ventilatory equivalent of CO2 (EqCO2, -3.8 L/min, BF10 = 1.1) and compared to CG in VE (-8.3 L/min, BF10 = 3.6), VCO2 (-215.9 L/min, BF10 = 3.0), EqCO2 (-3.7 L/min, BF10 = 1.1) and HR (-12.9 beats/min, BF10 = 3.4). FBG also showed a greater PrePOST positive increment in Tex (0.21 s, BF10 = 1.4) with respect to CG. At PreFINAL, FBG presented a greater positive increment compared to CG in Tt (4.4 min, BF10 = 3.2) and negative in VE/VCO2 intercept (-4.7, BF10 = 1.1). The use of FB added to a pulmonary rehabilitation programme in COPD patients could improve tolerance in the incremental exercise test and energy efficiency. However, there is only a statically significant difference between FBG and ONBG in EqCO2. Therefore, more studies are necessary to reach a definitive conclusion about including FB in a pulmonary rehabilitation programme.

Chronic Effects of a Training Program Using a Nasal Inspiratory Restriction Device on Elite Cyclists.

This study compared the response of a 9-week cycling training on ventilatory efficiency under two conditions: (i) Combined with respiratory muscle training (RMT) using a new nasal restriction device (FeelBreathe) (FB group) and (ii) without RMT (Control group). Eighteen healthy elite cyclists were randomly separated into the FB group (n = 10) or Control group (n = 8). Gas exchange was measured breath by breath to measure ventilatory efficiency during an incremental test on a cycloergometer before (Pre) and after (Post) the nine weeks of training. The FB group showed higher peak power (Δ (95%HDI) (0.82 W/kg (0.49, 1.17)), VO2max (5.27 mL/kg/min (0.69, 10.83)) and VT1 (29.3 W (1.8, 56.7)) compared to Control at PostFINAL. The FB group showed lower values from Pre to PostPRE in minute ventilation (VE) (-21.0 L/min (-29.7, -11.5)), Breathing frequency (BF) (-5.1 breaths/min (-9.4, -0.9)), carbon dioxide output (VCO2) (-0.5 L/min (-0.7, -0.2)), respiratory equivalents for oxygen (EqO2) (-0.8 L/min (-2.4, 0.8)), heart rate (HR) (-5.9 beats/min (-9.2, -2.5)),, respiratory exchange ratio (RER) (-0.1 (-0.1, -0.0) and a higher value in inspiratory time (Tin) (0.05 s (0.00, 0.10)), expiratory time (Tex) (0.11 s (0.05, 0.17)) and end-tidal partial pressure of CO2 (PETCO2) (0.3 mmHg (0.1, 0.6)). In conclusion, RMT using FB seems to be a new and easy alternative ergogenic tool which can be used at the same time as day-to-day training for performance enhancement.

A New Nasal Restriction Device Called FeelBreathe® Improves Breathing Patterns in Chronic Obstructive Pulmonary Disease Patients during Exercise.

A device called FeelBreathe (FB)® was designed, developed, and patented for inspiratory muscle training. The main aim was to determine the acute responses on lung ventilation, gas exchange, and heart rate during exercise in patients with chronic obstructive pulmonary disease (COPD) with and without the use of FB. In this study, a randomized cross-over trial was performed with 18 men diagnosed with COPD (FEV1 between 30% and 70% of its predicted value). Each participant randomly conducted two trials with 30 min of rest between them with the same protocol on a treadmill for 10 min at a constant rate of 50% of VO2peak. Each test was performed randomly and in a crossover randomized design in two different conditions: (1) oronasal breathing; and (2) nasal breathing with FB (nasal ventilatory flow restriction device). It was observed that FB had positive effects on dynamic hyperinflation, breathing pattern, and breathing efficiency, with higher expiratory and inspiratory time. Despite these differences, blood oxygen saturation percentage, oxygen uptake, and heart rate showed a similar response for both conditions during exercise. The results suggest that exercise performed with FB improved ventilatory responses compared to the oronasal mode in COPD patients. This new tool could be used during most daily tasks and exercise programs.

Effects of a Rehabilitation Programme with a Nasal Inspiratory Restriction Device on Exercise Capacity and Quality of Life in COPD.

OBJECTIVE: The objective was to assess the effects of a nasal restriction device for inspiratory muscle training, called Feelbreathe®, added to a rehabilitation program (RP) on exercise capacity, quality of life, dyspnea and inspiratory muscle strength in patients with stable COPD. METHODS: Patients were randomized into three groups, one performed a supervised RP using the Feelbreathe® device (FB group), the second group developed the same RP with oronasal breathing without FB (ONB group) and the third was the control group (CG). We evaluated inspiratory muscle strength (PImax), dyspnea (mMRC), quality of life (CAT) and exercise capacity (6MWT) before and after 8-week of RP. RESULTS: A total of 16 patients completed the study, seven in FB group, five in ONB group and four in the CG. After the RP, the FB group showed a significant increase in PImax (93.3 ± 19.1 vs. 123.0 ± 15.8 mmHg) and in the 6MWT distance (462.9 ± 71.8m vs. 529.1 ± 50.1 m) and a decrease in the CAT score (9.7 ± 6.5 vs. 5.9 ± 6.0) and in the mMRC dyspnea score. FB provides greater improvement in PImax, dyspnea, quality of life and 6MWT than ONB. CONCLUSIONS: The Feelbreathe® device provides greater improvements in quality of life, dyspnea, exercise capacity and inspiratory muscle strength compared to patients that did not use it.

Inertial flywheel resistance training and muscle oxygen saturation.

BACKGROUND: The inertial flywheel device causes an increase in eccentric overload during training. The aim was to study muscle oxygen saturation produced during an inertial flywheel squat training, comparing it with a barbell squat training. METHODS: Twelve male adults performed a barbell squat training (3×8 reps, 75-80% 1RM) and a flywheel squat training (3×8 reps, all-out). Muscle oxygen saturation (%SmO2), total hemoglobin (tHb), reoxygenation, heart rate (HR), lactate, vertical jumps, maximal voluntary isometric contraction and rated perceived exertion (RPE) were studied. RESULTS: Both protocols produced a significant decrease in %SmO2 and tHB during the sets of squats, and a significant increase in HR, lactates dand RPE after training. The flywheel squat protocol caused a greater decrease in %SmO2 than the barbell squat protocol in each of the sets of exercises (1st set: -67.5±7.2% vs. -53.7±16.2%; 2nd set: -67.2±13.5% vs. -53.6±15.4%; 3rd set: -68.1±13.0% vs. -55.0±17.0%), as well as a longer reoxygenation after finishing the training (61.7±12.6 vs. 55.7±13.7 s). CONCLUSIONS: Although no differences were found on a muscle fatigue level, the flywheel training brought on greater physiological stress than the barbell squat training, observing a greater decrease in muscle oxygen saturation and a longer reoxygenation.

Reliability and Validity of Tests to Assess Lower-Body Muscular Power in Children.

The purpose of this study was to analyze the reliability and the criterion-related validity of several lower-body muscular power tests (i.e., standing long jump [SLJ], squat jump, countermovement jump, and Abalakov jump) in children aged 6-12 years. Three hundred sixty three healthy children (168 girls) agreed to participate in this study. All the lower-body muscular power tests were performed twice (7 days apart), whereas the 1 repetition maximum (1 RM) leg extension test was performed 2 days after the first session of testing. All the tests showed a high reliability (intertrial difference close to 0 and no significant differences between trials, all p > 0.05). The association between the lower-body muscular power tests and 1 RM leg extension test was high (all p < 0.001). The SLJ and the Abalakov jump tests showed the highest association with 1 RM leg extension test (R = 0.700, test result, weight, height, sex, and age were added in the model). The SLJ test can be a useful tool to assess lower-body muscular power in children when laboratory methods are not feasible because it is practical, time efficient, and low in cost and equipment requirements.

Percentile values for muscular strength field tests in children aged 6 to 17 years: influence of weight status.

The aim of this study was to provide percentile values for 9 different muscular strength tests for Spanish children (1,513 boys and 1,265 girls) aged 6 to 17.9 years. The influence of body weight on the muscular strength level across age groups was also examined. Explosive strength was assessed by the throw ball test (upper body), standing broad jump, and vertical jump tests (lower body). Upper-body muscular endurance was assessed by push ups, bent arm hang, and pull ups tests, and abdominal muscular endurance was assessed by sit ups, curl ups in 30 seconds, and curl ups tests. Body mass index (BMI) was calculated. Participants were categorized according to the BMI international cut-off values as underweight, normalweight, overweight, and obese. Boys had significantly better scores than girls in all the studied tests, except in the 3 upper-body muscular endurance tests in the 6- to 7-year-old group and in the push ups test in the 8- to 9-year-old group. Underweight and normalweight individuals showed similar strength levels. Both underweight and normalweight children and adolescents had significantly higher performance than their overweight and obese counterparts in the lower-body explosive strength tests and in the push ups test in boys and bent arm hang test in both boys and girls. In conclusion, percentiles values of 9 muscular strength tests are provided. Percentiles values are of interest to identify the target population for primary prevention and to estimate the proportion of adolescents with high or low muscular strength levels. The overweight and obese groups had worse scores than their underweight and normalweight counterparts, whereas the underweight group had a similar performance to the normalweight group.

Criterion-related validity of the one-mile run/walk test in children aged 8-17 years.

We assessed the criterion-related validity of Cureton's equation for estimating peak oxygen consumption (VO(2peak)) from the one-mile run/walk test in endurance-trained children aged 8-17 years. Altogether, 66 physically active white children and adolescents (32 girls, 34 boys) completed a graded exercise test to volitional exhaustion and the one-mile run/walk test. Cureton's equation was used to estimate VO(2peak), and was assessed using several error measures. Agreement between measured VO(2peak) and estimated VO(2peak) was analysed by the Bland and Altman method. The correlation coefficient between measured VO(2peak) and one-mile run/walk time was -0.59 (P < 0.001) and that between measured and estimated VO(2peak) was 0.70 (P < 0.001). The mean difference between measured and estimated VO(2peak) was 10 ml . kg(-1) . min(-1) (95% CI = 9.2-11.8; P < 0.001). The standard error of the estimate was 3 ml . kg(-1) . min(-1), and the percentage error was 32%. There was a positive association between the measured and estimated VO(2peak) difference and the measured and estimated VO(2peak) mean, which indicates that the higher the VO(2peak) the higher the error of the estimate. These findings did not change markedly when the analyses were performed by sex, age group or body mass status. These results suggest that Cureton's equation systematically underestimates VO(2peak) in endurance-trained children with high VO(2peak).