This study evaluated the feasibility, safety, and findings from a protocol for exercise-bicycle ergometry in subacute-stroke survivors. Of 117 eligible candidates, 14 could not perform the test and 3 discontinued because of cardiac safety criteria. In the 100 completed tests, peak heart rate was 116 ± 19.1 beats/min; peak VO2 was 11.4 ± 3.7 ml · kg · min−1, peak METs were 3.3 ± 0.91, exercise duration was 5.1 ± 2.84 min., and Borg score was 14 ± 2.6. Among 71 tests, anaerobic threshold was achieved in 3.0 ± 1.7 min with a VO2 of 8.6 ± 1.7 ml · kg · min−1. After screening, this protocol is feasible and safe in subacute-stroke survivors with mild to moderate deficits. These stroke survivors have severely limited functional exercise capacity. Research and clinical practice in stroke rehabilitation should incorporate more comprehensive evaluation and treatment of endurance limitations.
Joni S. Yates, Stephanie Studenski, Steven Gollub, Robert Whitman, Subashan Perera, Sue Min Lai and Pamela W. Duncan
Lothar Rokitzki, Enno Logemann, Georg Huber, Elfriede Keck and Josef Keul
This study was undertaken to evaluate the effects of 5 months of α-tocopherol supplementation on physical performance during aerobic exercise training in 30 top-class cyclists. Antioxidative effects of supplementation were also studied. Plasma α-tocopherol concentration increased significantly in the vitamin E-supplemented group, whereas the placebo group showed a trend toward decrease. Physical performance did not improve in the α-tocopherol-supplemented group compared to the placebo group. Heart rates were also not significantly different. Lactate concentrations at the aerobic threshold and the anaerobic threshold were identical. Thus, there was no performance improvement in the α-tocopherol-supplemented group. However there was a significant reduction in CK in serum of the E-supplemented group. A trend toward decrease in GOT, GPT, and LDH was observed with α-tocopherol supplementation. Moreover, significantly reduced malondialdehyde serum levels were measured in the E-supplemented group. The findings indicate a protective effect of α-tocopherol supplementation against oxidative stress induced by strenuous exercise.
Lorenzo Pugliese, Simone Porcelli, Matteo Bonato, Gaspare Pavei, Antonio La Torre, Martina A. Maggioni, Giuseppe Bellistri and Mauro Marzorati
Recently, some studies have suggested that overall training intensity may be more important than training volume for improving swimming performance. However, those studies focused on very young subjects, and/or the difference between high-volume and high-intensity training was blurred. The aim of this study was to investigate in masters swimmers the effects of manipulation of training volume and intensity on performance and physiological variables.
A group of 10 male masters swimmers (age 32.3 ± 5.1 y) performed 2 different 6-wk training periods followed by 1 wk of tapering. The first period was characterized by high training volume performed at low intensity (HvLi), whereas the second period was characterized by low training volume performed at high intensity (LvHi). Peak oxygen consumption (V̇O2peak) during incremental arm exercise, individual anaerobic threshold (IAT), and 100-m, 400-m, and 2000-m-freestyle time were evaluated before and at the end of both training periods.
HvLi training significant increased V̇O2peak (11.9% ± 4.9% [mean change ± 90%CL], P = .002) and performance in the 400-m (–2.8% ± 1.8%, P = .002) and 2000-m (–3.4% ± 2.9%, P = .025), with a likely change in IAT (4.9% ± 4.7%, P > .05). After LvHi training, speed at IAT (12.4% ± 5.3%, P = .004) and 100-m performance (–1.2% ± 0.8%, P = .001) also improved, without any significant changes in V̇O2peak, 2000-m, and 400-m.
These findings indicate that in masters swimmers an increase of training volume may lead to an improvement of V̇O2peak and middle- to long-distance performance. However, a subsequent period of LvHi training maintains previous adjustments and positively affects anaerobic threshold and short-distance performance.
Andrew Pardue, Eric T. Trexler and Lisa K. Sprod
Extreme body composition demands of competitive bodybuilding have been associated with unfavorable physiological changes, including alterations in metabolic rate and endocrine profile. The current case study evaluated the effects of contest preparation (8 months), followed by recovery (5 months), on a competitive drug-free male bodybuilder over 13 months (M1-M13). Serum testosterone, triiodothyronine (T3), thyroxine (T4), cortisol, leptin, and ghrelin were measured throughout the study. Body composition (BodPod, dualenergy x-ray absorptiometry [DXA]), anaerobic power (Wingate test), and resting metabolic rate (RMR) were assessed monthly. Sleep was assessed monthly via the Pittsburgh Sleep Quality Index (PSQI) and actigraphy. From M1 to M8, testosterone (623–173 ng∙dL-1), T3 (123–40 ng∙dL-1), and T4 (5.8–4.1 mg∙dL-1) decreased, while cortisol (25.2–26.5 mg∙dL-1) and ghrelin (383–822 pg∙mL-1) increased. The participant lost 9.1 kg before competition as typical energy intake dropped from 3,860 to 1,724 kcal∙day-1; BodPod estimates of body fat percentage were 13.4% at M1, 9.6% at M8, and 14.9% at M13; DXA estimates were 13.8%, 5.1%, and 13.8%, respectively. Peak anaerobic power (753.0 to 536.5 Watts) and RMR (107.2% of predicted to 81.2% of predicted) also decreased throughout preparation. Subjective sleep quality decreased from M1 to M8, but objective measures indicated minimal change. By M13, physiological changes were largely, but not entirely, reversed. Contest preparation may yield transient, unfavorable changes in endocrine profile, power output, RMR, and subjective sleep outcomes. Research with larger samples must identify strategies that minimize unfavorable adaptations and facilitate recovery following competition.
Khalid S. Almuzaini
The first purpose of the present study was to test sensitivity of the Wingate anaerobic test (WAnT) to alterations in resistance settings. The second purpose was to investigate whether using optimal braking force on WAnT enhances its relation with a 50-m dash, a vertical jump (VJ), or a standing long jump (LJ) tests. Twenty-three 12 year-old boys performed a 50-m dash, VJ, LJ, and WAnT using four braking force resistances (BFR; .065, .070, .075, and .080 kp/kg BM). Results revealed significant (p ≤ .05) differences among the four BFRs in peak power (PP) and in mean power (MP). Post hoc tests indicated significant differences among all of the four BFRs in PP and between the 0.065 and both the 0.075 and the 0.08 kp/kg BM in MP. Results of Pearson correlation coefficients indicated that using the optimal BFR for both PP and MP enhanced their relation with performance during the 50-m dash, VJ, and LJ tests. Also, partial correlation coefficients, controlling for body weight, height, percent fat, or body mass index supported these findings. It was concluded that for untrained, healthy 12-year-old boys, WAnT is sensitive to incremental alterations in resistance settings ranging from 0.065 to 0.080 kp/kg body mass. To be more specific, PP is sensitive to small increments in BFR, while MP is only sensitive to larger increments in BFR. Furthermore, optimizing resistance settings on WAnT enhances its relationship with anaerobic performance tasks, such as the 50-m dash, the VJ, and the LJ.
Ibrahim Ouergui, Philip Davis, Nizar Houcine, Hamza Marzouki, Monia Zaouali, Emerson Franchini, Nabil Gmada and Ezzedine Bouhlel
The aim of the current study was to investigate the hormonal, physiological, and physical responses of simulated kickboxing competition and evaluate if there was a difference between winners and losers. Twenty athletes of regional and national level participated in the study (mean ± SD age 21.3 ± 2.7 y, height 170.0 ± 5.0 cm). Hormone (cortisol, testosterone, growth hormone), blood lactate [La], and glucose concentrations, as well as upper-body Wingate test and countermovement-jump (CMJ) performances, were measured before and after combats. Heart rate (HR) was measured throughout rounds 1, 2, and 3 and rating of perceived exertion (RPE) was taken after each round. All combats were recorded and analyzed to determine the length of different activity phases (high-intensity, low-intensity, and referee pause) and the frequency of techniques. Hormones, glucose, [La], HR, and RPE increased (all P < .001) precombat to postcombat, while a decrease was observed for CMJ, Wingate test performance, body mass (all P < .001), and time of high-intensity activities (P = .005). There was no difference between winners and losers for hormonal, physiological, and physical variables (P > .05). However, winners executed more jab cross, total punches, roundhouse kicks, total kicks, and total attacking techniques (all P < .042) than losers. Kickboxing is an intermittent physically demanding sport that induces changes in the stress-related hormones soliciting the anaerobic lactic system. Training should be oriented to enhance kickboxers’ anaerobic lactic fitness and their ability to strike at a sufficient rate. Further investigation is needed to identify possible differences in tactical and mental abilities that offer some insight into what makes winners winners.
Jan Boone and Jan Bourgois
The current study aimed to gain insight into the physiological profile of elite basketball players in Belgium in relation to their position on the field.
The group consisted of 144 players, divided into 5 groups according to position (point guards [PGs], shooting guards [SGs], small forwards [SFs], power forwards [PFs], and centers [Cs]). The anthropometrics were measured and the subjects underwent fitness tests (incremental running test, 10-m sprint, 5 ×-10 m, squat and countermovement jump, isokinetic test) to obtain insight into endurance, speed, agility, and power. The parameters of these tests were compared among the different positions by means of 1-way variance analysis (MANOVA). Tukey post hoc tests were performed in case of a significant MANOVA.
It was observed that Cs were taller and heavier and had a higher percentage body fat than PGs and SGs. For the anaerobic sprint test Cs were slower than the other positions. For the 5 × 10-m the PGs and SGs were faster than SFs and PFs. For the jump test Cs displayed a significantly lower absolute performance than the other positions. PGs and SGs had a higher VO2peak and speed at the anaerobic threshold than PFs and Cs. The isokinetic strength test showed that the quadriceps muscle group of Cs could exert a higher torque during knee extension than the other positions.
The current study showed that the physiological profile of elite players in the Belgian first division differs by player position. More specifically, guards were characterized by high endurance, speed, and agility, whereas centers and power forwards had higher muscle strength than the other positions.
Catalina Fernández-Campos, Ana L. Dengo and José Moncada-Jiménez
To determine the acute effect of an energy drink (ED) on physical performance of professional female volleyball players. 19 females (age= 22.3 ± 4.9 yr.; height= 171.8 ± 9.4 cm; weight= 65.2 ± 10.1 kg) participated in a randomized, crossover, double-blind study to measure grip strength, vertical jump and anaerobic power in 3 different sessions (ED, placebo [PL] or no beverage [CTL]). For each session, participants arrived in a fasted state, consumed a standardized breakfast meal, and 1 hr later completed the 3 baseline performance tests without having ingested the beverage. After completing the premeasurements, the athletes drank 6 ml/kg of body weight of the ED or PL and in the CTL condition no beverage was consumed. Posttest measurements were taken 30 min after the ingestion of liquids. A 3 × 2 repeated-measures ANOVA revealed no significant within-session and measurement time interactions for each performance test. Regardless of the measurement time, right hand grip strength was significantly higher in the ED condition (34.6 ± 0.9 kg) compared with PL (33.4 ± 1.1 kg) and CTL (33.6 ± 1.0 kg) (p > 0.05). Regardless of the beverage ingested, averaged right hand grip strength, taking into account all 3 testing conditions, increased from pre to posttesting (Pre = 33.8 ± 0.9 kg vs. Post = 33.9 ± 1.0 kg; p = 0.029), as did the averaged fatigue index, obtained from the anaerobic power test (Pre = 65.9± 2.2% vs. Post = 68.7± 2.0%; p= 0.049). The acute ingestion of an ED did not improve physical performance of professional Costa Rican female volleyball players.
Yeshayahu Hutzler, Martin Grunze and Rolf Kaiser
Eleven male elite wheelchair basketball players took part in an all-out, high-velocity, “Wingate”-type ergometric test lasting 30 s. An electrically braked and electronically controlled roller device was used to measure power and velocity. A breath-by-breath metabolic measurement cart collected net O2 uptake prior to, during, and after the test. Average braking load and velocity were 9.91 N · m and 5.09 m · s-1, respectively. Mean total work during the test was 4,468.47 ± 1,326 J. Based on net O2 cost and estimating a 10% efficiency, the aerobic contribution would be 29.8 ± 10.2%. Therefore, performance in this test seems to be predominantly anaerobic. Velocity variables of the subjects included in this study had a significant relationship to power variables and thus are considered valid for measuring peak performance, mean performance, and fatigue. A regression analysis utilizing wheel size and function as independent variables presented a significant relationship to peak velocity (P <.005). Further findings indicated variability in technique among subjects that led to training suggestions.
Joan M. Eckerson, Dona J. Housh, Terry J. Housh and Glen O. Johnson
The purpose of this investigation was to determine the changes in body composition, isokinetic strength, and muscular power in high school wrestlers across a season of competition. Wrestlers were measured (preseason and postseason) for body composition and isokinetic peak torque for flexion and extension of the dominant forearm and leg. Each subject also completed Wingate anaerobic tests to determine changes in mean power and peak power (PP) of the legs. The results indicated that body weight (BW), fat weight, and percent fat decreased (p < .002) across the wrestling season. PP and absolute peak torque for forearm and leg extension (LE) at 30°·s−1; forearm flexion (FF) at 30, 180, and 300°·s−1; and leg flexion (LF) at 180 and 300°·s−1 were significantly (p < .05) lower postseason. Relative peak torque (adjusted for BW) decreased (p < .05) across the season for LE at 30°·s−1 as well as FF and LF at 180°·s−1. Therefore, changes in BW were not associated with functional advantages in terms of strength or muscular power.