scholarly journals Stepwise Regression and Latent Profile Analyses of Locomotor Outcomes Poststroke

Stroke ◽  
2020 ◽  
Vol 51 (10) ◽  
pp. 3074-3082 ◽  
Author(s):  
T. George Hornby ◽  
Christopher E. Henderson ◽  
Carey L. Holleran ◽  
Linda Lovell ◽  
Elliot J. Roth ◽  
...  

Background and Purpose: Previous data suggest patient demographics and clinical presentation are primary predictors of motor recovery poststroke, with minimal contributions of physical interventions. Other studies indicate consistent associations between the amount and intensity of stepping practice with locomotor outcomes. The goal of this study was to determine the relative contributions of these combined variables to locomotor outcomes poststroke across a range of patient demographics and baseline function. Methods: Data were pooled from 3 separate trials evaluating the efficacy of high-intensity training, low-intensity training, and conventional interventions. Demographics, clinical characteristics, and training activities from 144 participants >1-month poststroke were included in stepwise regression analyses to determine their relative contributions to locomotor outcomes. Subsequent latent profile analyses evaluated differences in classes of participants based on their responses to interventions. Results: Stepwise regressions indicate primary contributions of stepping activity on locomotor outcomes, with additional influences of age, duration poststroke, and baseline function. Latent profile analyses revealed 2 main classes of outcomes, with the largest gains in those who received high-intensity training and achieved the greatest amounts of stepping practice. Regression and latent profile analyses of only high-intensity training participants indicated age, baseline function, and training activities were primary determinants of locomotor gains. Participants with the smallest gains were older (≈60 years), presented with slower gait speeds (<0.40 m/s), and performed 600 to 1000 less steps/session. Conclusions: Regression and cluster analyses reveal primary contributions of training interventions on mobility outcomes in patients >1-month poststroke. Age, duration poststroke, and baseline impairments were secondary predictors. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02507466 and NCT01789853.

Author(s):  
In-Dong KIM

Background: This study investigated the effect of sodium bicarbonate (HCO3-) intake on maximum muscle strength variables during eight weeks of high-intensity exercise of a sprinter. Methods: The study was conducted on 30 elite sprint athletes in Seoul, Republic of Korea as in 2016 with ≥3 yr of an athletic career by assigning 10 each to three groups (the control, training, and sodium bicarbonate-training combination groups [HCO3- and training group]). The training group and the HCO3- and training group participated in a high-intensity exercise program for 90 min per session, five days a week for eight weeks in total, and it involved 80%-90% heart rate max intensity increase every 2-3 weeks, and allocation of internal exercise, aquatic exercise, and hill exercise. HCO3- was provided to the HCO3- and training group, and involved an intake of 300 g of HCO3- per 1 kg body weight, once a day, 90 min prior to the high-intensity exercise program for eight weeks. Results: HCO3- intake during high-intensity training had a positive effect on maximum muscle strength. A positive effect was observed in the HCO3- and training groups; however, the effect on maximum muscle strength was stronger in the HCO3- and training groups. In particular, the effect on maximum muscle strength was observed during extension than during flexing starting from the fourth week of the exercise program with HCO3- intake. Conclusion: HCO3- intake during 8 weeks of high-intensity training began to have a positive effect on maximum muscle strength. Therefore, HCO3- intake during high-intensity exercise is effective in improving exercise capacity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eugenia Murawska-Ciałowicz ◽  
Gilmara Gomes de Assis ◽  
Filipe Manuel Clemente ◽  
Yuri Feito ◽  
Petr Stastny ◽  
...  

AbstractThis study examined the effects of a nine-week intervention of four different high-intensity training modalities [high-intensity functional training (HIFT), high-intensity interval training (HIIT), high-intensity power training (HIPT), and high-intensity endurance training (HIET)] on the resting concentration of brain-derived neurotropic factor (BDNF). In addition, we evaluated the BDNF responses to Graded Exercise Test (GXT) and Wingate Anaerobic Test (WAnT) in men. Thirty-five healthy individuals with body mass index 25.55 ± 2.35 kg/m2 voluntarily participated in this study and were randomly assigned into four training groups. During nine-weeks they completed three exercise sessions per week for one-hour. BDNF was analyzed before and after a GXT and WAnT in two stages: (stage 0—before training and stage 9—after nine weeks of training). At stage 0, an increase in BDNF concentration was observed in HIFT (33%; p < 0.05), HIPT (36%; p < 0.05) and HIIT (38%; p < 0.05) after GXT. Even though HIET showed an increase in BDNF (10%) this was not statistically significant (p > 0.05). At stage 9, higher BDNF levels after GXT were seen only for the HIFT (30%; p < 0.05) and HIIT (18%; p < 0.05) groups. Reduction in BDNF levels were noted after the WAnT in stage 0 for HIFT (− 47%; p < 0.01), HIPT (− 49%; p < 0.001), HIET (− 18%; p < 0.05)], with no changes in the HIIT group (− 2%). At stage 9, BDNF was also reduced after WAnT, although these changes were lower compared to stage 0. The reduced level of BDNF was noted in the HIFT (− 28%; p < 0.05), and HIPT (− 19%;p < 0.05) groups. Additionally, all groups saw an improvement in VO2max (8%; p < 0.001), while BDNF was also correlated with lactate and minute ventilation and selected WAnT parameters. Our research has shown that resting values of BDNF after nine weeks of different forms of high-intensity training (HIT) have not changed or were reduced. Resting BDNF measured at 3th (before GXT at stage 9) and 6th day after long lasting HITs (before WAnT at stage 9) did not differed (before GXT), but in comparison to the resting value before WAnT at the baseline state, was lower in three groups. It appears that BDNF levels after one bout of exercise is depended on duration time, intensity and type of test/exercise.


2016 ◽  
Vol 44 (3) ◽  
pp. 208-216 ◽  
Author(s):  
Mehdi Kargarfard ◽  
Eddie T. C. Lam ◽  
Ardalan Shariat ◽  
Mahmoud Asle Mohammadi ◽  
Saleh Afrasiabi ◽  
...  

2000 ◽  
Vol 279 (1) ◽  
pp. R152-R160 ◽  
Author(s):  
Niels Ørtenblad ◽  
Per K. Lunde ◽  
Klaus Levin ◽  
Jesper L. Andersen ◽  
Preben K. Pedersen

To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% ( P < 0.01) after training. The 5-wk sprint training induced a significantly higher ( P < 0.05) peak rate of AgNO3-stimulated Ca2+ release from 709 (range 560–877; before) to 774 (596–977) arbitrary units Ca2+ ⋅ g protein− 1 ⋅ min− 1(after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% ( P < 0.05) increase in total number of RyR. No significant differences in Ca2+ uptake rate and Ca2+-ATPase capacity were observed following the training, despite that the relative density of Ca2+-ATPase isoforms SERCA1 and SERCA2 had increased 41% and 55%, respectively ( P < 0.05). These data suggest that high-intensity training induces an enhanced peak SR Ca2+ release, due to an enhanced total volume of SR, whereas SR Ca2+ sequestration function is not altered.


2017 ◽  
Vol 216 (4) ◽  
pp. 384.e1-384.e11 ◽  
Author(s):  
Camilla M. Mandrup ◽  
Jon Egelund ◽  
Michael Nyberg ◽  
Martina H. Lundberg Slingsby ◽  
Caroline B. Andersen ◽  
...  

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