Patrícia Dias Pantoja

Effect of Resistive Exercise on Muscle Damage in Water and on Land

Pantoja, PD, Alberton, CL, Pilla, C, Vendrusculo, AP, and Kruel, LFM. Effect of resistive exercise on muscle damage in water and on land. J Strength Cond Res 23(3): 1051-1054, 2009-The purpose of this study was to compare the effects of resistance exercise in water and on land on blood levels of creatine kinase (CK), a known indirect marker of muscle damage. Nine men (age: 23 ± 1.58 years; weight: 79.37 ± 11.15 kg; height: 176.33 ± 4.09 cm), who had not practiced resistance training for at least 6 months before this experiment, performed 3 sets of maximum elbow flexion and extension exercises in water and on land, separated by 2-minute periods of rest. A 10-repetition maximum test was used to load control on land with free weights, and in water the exercise was performed at maximum velocity with aquatic resistance equipment. The duration of the exercise in water was the same as that performed on land, to reproduce the same metabolic route. Plasma CK activity was determined using a commercially available kit (Labtest Enzymatic-UV) before exercise, after exercise, and at 24 and 48 hours after exercise. Significant increases in CK were found at 48 hours postexercise on land (preexercise land: 160.75 ± 96.05 U·L−1; 48 hours: 326.87 ± 240.84 U·L−1), and significant differences were found between land and water (preexercise water: 147.75 ± 46.48 U·L−1; 48 hours: 121.75 ± 30.86 U·L−1) for this measure. However, no significant differences were found in water. In conclusion, the water environment influenced the absence of significant muscle damage. This type of exercise protocol may be appropriate for situations in which limited muscle tissue damage is desired.

Effects of Nordic walking training on functional parameters in Parkinson's disease: a randomized controlled clinical trial.

We compare the effects of Nordic walking training (NW) and Free walk (FW) on functional parameters (motor symptoms, balance) and functional mobility (Timed Up and Go at Self‐selected Speed – TUGSS, and at forced speed, TUGFS; Self‐selected Walking Speed, SSW; locomotor rehabilitation index, LRI) of Parkinsons disease (PD) patients. The study included 33 patients with clinical diagnosis of idiopathic PD, and staging between 1 and 4 in the Hoehn and Yahr scale (H&Y) randomized into two groups: NW (N = 16) and FW (N = 17) for 6 weeks. Baseline characteristics were compared trough a one‐way ANOVA. Outcomes were analyzed using the Generalized Estimation Equations (GEE) with a Bonferroni post‐hoc. Data were analyzed using SPSS v.20.0. Improvements in UPDRS III (P < 0.001), balance scores (P < 0.035), TUGSS distance (P < 0.001), TUGFS distance (P < 0.001), SSW (P < 0.001), and LRI (P < 0.001) were found for both groups. However, the NW group showed significant differences (P < 0.001) when compared to the FW group for the functional mobility. We conclude the NW improves functional parameters and walking mobility demonstrating that NW is as effective as the FW, including benefits for FW on the functional mobility of people with PD.

Sprint Acceleration Mechanics in Masters Athletes.

PURPOSE The best sprint performances are usually reached between the ages of 20 and 30 yr; however, even in well-trained individuals, performance continues to decrease with age. Although this inevitable decrease in performance has been related to reductions in muscular force, velocity, and power capabilities, these measures have not been assessed in the specific context of sprinting. The aim of this study was to investigate the mechanical outputs of sprinting acceleration among masters sprinters to better understand the mechanical underpinnings of the age-related decrease in sprint performance. METHODS The study took place during an international masters competition, with testing performed at the end of the warm-up for official sprint races. Horizontal ground reaction force, velocity, mechanical power outputs, and mechanical effectiveness of force application were estimated from running velocity-time data during a 30-m sprint acceleration in 27 male sprinters (39-96 yr). Data were presented in the form of age-related changes and compared with elite young sprinters data. RESULTS Maximal force, velocity, and power outputs decreased linearly with age (all r > 0.84, P < 0.001), at a rate of ~1% per year. Maximal power of the oldest subject tested was approximately one-ninth of that of younger world-class sprinters (3.57 vs 32.1 W·kg). Although the maximal effectiveness of horizontal force application also decreased with age, its decrease with increasing velocity within the sprint acceleration was not age dependent. CONCLUSIONS In addition to lower neuromuscular force, velocity, and power outputs, masters sprinters had a comparatively lower effectiveness of force application, especially at the beginning of the sprint.

Running energy cost and spring-mass behavior in young versus older trained athletes

PURPOSE The aim of this study was to compare energy cost of running and lower limb spring-mass characteristics and maximal power between young and older highly trained runners. METHODS Twenty highly trained male endurance runners were divided into two groups: young and master athletes. Two testing sessions were used to measure and compare (i) lower limb power during three jumping tests (squat jump (SJ), countermovement jump (CMJ), and rebound jump (RJ)) as well as stiffness during the RJ test and running trials (using an OptoJump system (Microgate, Bolzano, Italy) placed on the floor for jumping and on each side of the treadmill belt for running), and (ii) the energy cost of running and oxygen consumption (V˙O2) kinetics (using an Oxycon Pro breath-by-breath gas analyzer (Jaeger, Höchberg, Germany)) at three speeds: 10 km·h, self-selected speed, and speed corresponding to 90% of the second ventilatory threshold (VT2). RESULTS Energy cost of running was higher in masters than in young athletes at all speeds (10 km·h, 13.0%; self-selected, 10.8%; 90% VT2, 7.7% on average). Jumping power was lower in masters (SJ, -28.0%; CMJ, -30.5%; RJ, -27.9%) and significantly correlated with energy cost at 10 km·h and at self-selected speed (10 km·h: r = -0.71, -0.70, -0.47; self-selected speed: r = -0.76, -0.74, -0.58, respectively). RJ stiffness was also lower in masters (-27.8%), although stiffness during running showed no difference between groups. CONCLUSIONS A long-lasting running practice seemed to preserve the bouncing mechanism of master athletes, yet their energy cost was higher when compared with younger runners, which might have been associated with a lower muscle power.

Water-Based Concurrent Training Improves Peak Oxygen Uptake, Rate of Force Development, Jump Height, and Neuromuscular Economy in Young Women

Abstract Pinto, SS, Alberton, CL, Cadore, EL, Zaffari, P, Baroni, BM, Lanferdini, FJ, Radaelli, R, Pantoja, PD, Peyré-Tartaruga, LA, Wolf Schoenell, MC, Vaz, MA, and Kruel, LFM. Water-based concurrent training improves peak oxygen uptake, rate of force development, jump height, and neuromuscular economy in young women. J Strength Cond Res 29(7): 1846–1854, 2015—The study investigated the effects of different intrasession exercise sequences on the cardiorespiratory and neuromuscular adaptations induced by water-based concurrent training in young subjects. Twenty-six healthy young women (25.1 ± 2.9 years) were placed into 2 water-based concurrent training groups: resistance before (RA, n = 13) or after (AR, n = 13) aerobic training. Subjects trained resistance and aerobic training during 12 weeks, 2 times per week performing both exercise types in the same training session. Peak oxygen uptake (V[Combining Dot Above]O2peak), rate of force development (RFD) obtained during an isometric peak torque knee extension protocol, jump height, and neuromuscular economy (normalized electromyography at 80% of pretraining knee extension isometric peak torque) in young women were determined. After training, there was a significant increase (p < 0.001) in both RA and AR in the V[Combining Dot Above]O2peak, with no differences between groups (7 vs. 5%). The maximal isometric knee extension RFD showed significant increases (p = 0.003) after training (RA: 19 vs. AR: 30%), and both groups presented similar gains. In addition, the countermovement jump height also increased (p = 0.034) after training (RA: 5% vs. AR: 6%), with no difference between groups. After training, there were significant improvements on vastus lateralis (p < 0.001) (RA: −13% vs. AR: −20%) and rectus femoris (p = 0.025) (RA: −17% vs. AR: −7%) neuromuscular economy, with no difference between groups. In conclusion, 12 weeks of water-based concurrent training improved the peak oxygen uptake, RFD, jump height, and neuromuscular economy in young women independent from the intrasession exercise sequence.

Does Aerobic Exercise Impair Neuromuscular Function During Water-Based Resistance Exercises?

ABSTRACT Purpose: The purpose of this study was to investigate the acute effects of water-based aerobic exercises on the performance of water-based resistance exercises by assessing kinematic parameters during protocols and neuromuscular responses after them. Method: Ten women performed 2 water-based protocols (i.e., resistance and concurrent water-based exercises) on separate days. We evaluated isometric force and electromyographic signal (sEMG) before and after protocols and analyzed kinematic parameters during a water-based resistance exercise. Results: There was no significant difference between knee extension force production and sEMG from the vastus lateralis during the maximal voluntary contraction performed before and after the protocols. However, sEMG from the rectus femoris presented a significant difference between pretest and posttest measurements in both water-based protocols with greater values in the measurement after the end of the protocol (p = .046). The peak angular velocity of knee extension and mean angular velocity of knee extension and flexion showed similar values among the sets, with no difference between protocols. The peak angular velocity of knee flexion presented greater values in the water-based resistance exercises compared with the water-based concurrent protocol in the last set (p < .001). Conclusion: The main impairment induced by the water-based concurrent exercises was the lower peak angular velocity in the knee flexors compared with water-based resistance exercises alone.

Effect of weighted sled towing on sprinting effectiveness, power and force-velocity relationship

This study aimed to compare the components of force-velocity (F-V) and power-velocity (P-V) profiles and the mechanical effectiveness of force application (or force ratio–RF) among various sled-towing loads during the entire acceleration phase of a weighted sled sprint. Eighteen sprinters performed four 50-m sprints in various conditions: unloaded; with a load corresponding to 20% of the athlete’s body mass (BM); with a load of 30% BM; and with a load of 40% BM. Data were collected with five video cameras, and the images were digitised to obtain velocity from the derivation of the centre-of-mass position. F-V and P-V components and RF were estimated from sprinting velocity-time data for each load using a validated method that is based on an inverse dynamic approach applied to the sprinter’s centre-of-mass (it models the horizontal antero-posterior and vertical ground reaction force components) and requires only measurement of anthropometric and spatiotemporal variables (body mass, stature and instantaneous position or velocity during the acceleration phase). The theoretical maximal velocity decreased with load compared with the unloaded condition (for 20% BM: -6%, effect size (ES) = 0,38; for 30% BM: -15%, ES = 1.02; for 40% BM: -18%, ES = 1.10). The theoretical maximal horizontal force (F0) and maximal power were not different among conditions. However, power at the end of the acceleration phase increased with load (40% BM vs 0%: 72%; ES = 2.73) as well as the maximal mechanical effectiveness (12%; ES = 0.85). The linear decrease in RF was different between 30 or 40% BM and the unloaded condition (-23%; ES = 0.74 and 0.66). Better effectiveness may be developed with 40% BM load at the beginning of the acceleration and with the various load-induced changes in the components of the F-V and P-V relationships, allowing a more accurate determination of optimal loading conditions for maximizing power.

GLYCEMIC THRESHOLD AS AN ALTERNATIVE METHOD TO IDENTIFY THE ANAEROBIC THRESHOLD IN PATIENTS WITH TYPE 2 DIABETES

Purpose: To analyze the agreement between the velocity, heart rate, and oxygen uptake values corresponding to second ventilatory threshold and glycemic threshold in patients with type 2 diabetes. Methods: Twenty-four untrained patients (55.1 ± 8.9 years) were evaluated. Three different parameters of training intensity corresponding to anaerobic threshold, one mechanical (velocity) and two physiological (heart rate and oxygen uptake) parameters, were identified by a classical method (second ventilatory threshold) and by an alternative method (glycemic threshold). To determine the threshold values, patients performed an incremental treadmill test, with an initial velocity of 3 km.h-1 for 3 min, that was then increased by 1 km.h-1 every 2 min. Comparisons between mean values and the degree of agreement between second ventilatory threshold and glycemic threshold were analyzed using the paired t-test and Bland-Altman test, respectively. Results: All patients performed the tests appropriately, and no adverse effects were recorded. Patients demonstrated similar mean velocity (p = 0.25), heart rate (p = 0.97) and oxygen uptake (p = 0.71) between the ventilatory threshold (6.4 ± 0.6 km.h-1, 130.1 ± 18.7 bpm, 15.2 ± 3.5 ml.kg.min-1) and the glycemic threshold (6.2 ± 0.9 km.h-1, 130.2 ± 12.8 bpm, 15.0 ± 3.8 ml.kg.min-1). Conclusion: The present study indicates an agreement between the glycemic and second ventilatory methods in determination of the anaerobic threshold of patients with type 2 diabetes; and thus, either method may be used for these patients.

Effects of load carriage on physiological determinants in adventure racers

Adventure racing athletes need run carrying loads during the race. A better understanding of how different loads influence physiological determinants in adventure racers could provide useful insights to gauge training interventions to improve running performance. We compare the maximum oxygen uptake (VO2max), the cost of transport (C) and ventilatory thresholds of twelve adventure running athletes at three load conditions: unloaded, 7 and 15% of body mass. Twelve healthy men experienced athletes of Adventure Racing (age 31.3 ± 7.7 years, height 1.81 ± 0.05 m, body mass 75.5 ± 9.1 kg) carried out three maximal progressive (VO2max protocol) and three submaximal constant-load (running cost protocol) tests, defined in the following quasi-randomized conditions: unloaded, 7% and, 15% of body mass. The VO2max (unload: 59.7 ± 5.9; 7%: 61.7 ± 6.6 and 15%: 64.6 ± 5.4 ml kg-1 min-1) did not change among the conditions. While the 7% condition does neither modify the C nor the ventilatory thresholds, the 15% condition resulted in a higher C (5.2 ± 0.9 J kg-1 m-1; P = 0.001; d = 1.48) than the unloaded condition (4.0 ± 0.7 J kg-1 m-1). First ventilatory threshold was greater at 15% than control condition (+15.5%; P = 0.003; d = 1.44). Interestingly, the velocities on the severe-intensity domain (between second ventilatory threshold and VO2max) were reduced 1% equivalently to 1% increasing load (relative to body mass). The loading until 15% of body mass seems to affect partially the crucial metabolic and ventilatory parameters, specifically the C but not the VO2max. These findings are compatible with the concept that interventions that enhance running economy with loads may improve the running performance of adventure racing’s athletes.

Neuromuscular Responses of Elite Skaters During Different Roller Figure Skating Jumps

Abstract This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.