Investigating the Effects of Endurance Training on Heart Rate Variability in Female Swimmer Athletes

It is important for elite endurance athletes to have practical and reliable means of measuring fatigue throughout their training. Variations in Autonomic Nervous System activity (ANS) may provide an effective marker of fatigue and of recovery. ANS control of heart rate is well known to be affected by exercise training, and those adaptations can be determined using measures of heart rate variability (HRV). Previous research has examined the effect of training on HRV and ANS control of heart rate in males, there is a lack of any comprehensive studies that address adaptations in female athletes. Therefore, the purpose of this study was to investigate the changes in HRV and ANS fluctuations in female swimmer athletes throughout an entire collegiate swim season. 9 Division I female swimmers (Age: 20.6±1.01) were used to determine HRV at three different points in their competitive training: pre-season, mid-season, and post-season. During each testing session, HRV was measured both at rest and during a maximal 400 yd freestyle swim. Heart rate values were determined using Polar™ heart rate monitors, and the HRV analyses was conducted using Kubios 2.0 HRV analysis software. Global ANS balance was shown to significantly shift towards Sympathetic (SNS) predominance during the mid-season testing and significantly shift towards parasympathetic (PNS) predominance during post-season testing. HRV analysis appears to be an appropriate tool to monitor the effects of physical training loads on performance and fitness in female athletes, and it can be used to help identify and prevent overtraining states

Effectiveness of Reverse vs. Traditional Linear Training Periodization in Triathlon

The present research aimed to analyze the modification in performance, body composition, and autonomic modulation of reverse and traditional linear training periodization in amateur triathletes.We analyzed running and swimming performance, strengthmanifestation, body composition, and autonomic modulation before and after a traditional linear training periodization (four weeks of volume-based training plus four weeks of intensity-based training plus two-week tapering), a reverse linear training periodization (four weeks of intensity-based training plus four weeks of volume-based training plus two-week tapering), and a free training control physical active group (10-week free training) in 32 amateur athletes. Independently of the periodization model, the combination of two four-week mesocycles followed by a two-week taper is an e ciency strategy to avoid overreaching, obtaining an increase in parasympathetic modulation. Moreover, both types of training periodization proposed in this study do not modified body composition of amateur triathletes. Also, compared with traditional periodization, reverse periodization e ciently improves horizontal jump performance. Finally, reverse and traditional periodization were an e ective strategy to improve running biomechanical, performance, and physiological variables, as well as e cient periodization strategies to improve swimming technical ability, aerobic, and anaerobic swimming performance

Acute Effects of the Training Mask on Short-Term Recovery During Rowing Intervals

The purpose of this study was to examine the acute effects of the Training Mask 2.0 (TM) on performance (m), blood lactate, heart rate recovery (HRR), stroke volume (SV), cardiac output (Q̇), heart rate variability (HRV), and breath rate recovery (BRR) when used during short-term recovery. Methods: Seven trained males completed two interval training conditions (TM and Sham TM). Each condition consisted of five, 1-min, max effort rows with 3-min recoveries. The TM (or Sham TM) was worn during each 3-min recovery. A repeated measures 2x5 (condition x interval) ANOVA was used to determine significant main effects for condition or interval. Post-hoc analysis was conducted using a one-way ANOVA to identify differences in conditions or intervals with the Bonferroni adjustment. Results: There were no differences between TM and Sham TM conditions for performance (m) (p = 0.094), blood lactate (p = 0.495), HRR (p = 0.533), SV (p = 0.672), Q̇ (p = 0.775), or HRV (p = 0.158), while BRR was improved in the TM condition (p = 0.008). Conclusion: The use of the TM during short-term recovery does not improve rowing performance (m), blood lactate, HRR, SV, Q̇, or HRV during interval training. Contrary to anecdotal reports, the implications for the TM to enhance short-term recovery are not supported

Effects of Deep Slow Breath Training on Performance and Recovery During High Intensity Interval Cycling

The present investigation sought to delineate the effects of a six-week deep slow breathing (DSB) program on measures of cycling performance (mean power: MP), recovery (heart rate recovery: HRR, and expired carbon dioxide: VCO2), and pulmonary capacities (vital capacity: VC, forced expiratory volume: FEV1, and maximum voluntary ventilation: MVV). Twenty male cyclists were divided into training (n=10) and control (n=10) groups, where the training group completed a six-week DSB program in addition to their own training while the control group completed no breathe training. Participants completed two testing sessions, one before and one after the six-week period. Testing sessions involved three repeated Wingate Anaerobic Tests (WAnT) with three minutes of passive recovery between each interval. MP was recorded for each WAnT while measures of VCO2 and HRR were taken immediately following each WAnT. No significant (p \u3c 0.05) differences were found between groups for any of the variables measured, while both groups exhibited increase MP in the second WAnT (T2) following the six-week training period (Treatment: pre: 516.30 ± 20.82 W versus post: 536.38 ± 20.62 W; p = 0.010; Control: pre: 549.93 ± 18.66 W versus post: 567.83 ± 18.44 W; p = 0.010). The results presented here suggest DSB provides no performance benefit relevant to recovery or pulmonary capabilities during high intensity interval cycling, beyond those which are incurred via endurance training

The effects of aerobic interval training on heart rate recovery after cardiac resynchronization therapy

Background: Heart failure is characterized by an autonomic nervous system dysfunction which leads to sympathetic overactivation and parasympathetic imbalance, culminating in central and peripheral dysfunction. In advanced HF, cardiac resynchronization therapy (CRT) and exercise training seem toimprove these conditions and result in improved functional and clinical parameters. A growing body of evidence supports the benefits of aerobic interval training (AIT) in other several HF populations, but less is known about its influence on autonomic function. Here we assessed the effects of AIT on the heart rate recovery (HRR), an indicator of parasympathetic activity. All participants had HF with a reduced ejection fraction, and six days before the intervention, underwent cardiac surgery. Our objective was to compare if the additive effect of AIT to CRT could indeed result in improved vagal reactivation, measured by the difference between the peak heart rate and the HRR at one minute (HRR1diff). Methods: Twenty-nine stable patients (aged 68.96 ± 9.92; VEF< 27 ; and a V O2Peak= 15 mL.kg-1.min-1) who were receiving optimal medical treatment, were randomized either to the control group, or the AIT group. The AIT group exercised twice a week, and began each session with a 10 minute warm-up (50-60% of the peak heart rate), followed by four intervals of 2-minutes (90-95% of the peak heart rate) and a 2-minute recovery (60-70% of the peak heart rate). After the first month, the 2-minute intervals were changed to 4-minute intervals and 3-minutes recovery. After cardiopulmonary exercise testing (CPET) to maximal volitional exertion, using the modified Bruce protocol, patients were seated and the HRR was immediately assessed. Results: After the six months of intervention our main effects were significant for V O2Peak (p= .010) and CPET duration (p= .025). Thus, after testing for simple main effects, only the AIT group depicted significant changes in the post-intervention for: V O2Peak (p= .013), CPET duration (p= .020), heart rate reserve (p= .035), peak pulse pressure (p= .036), and the HRR1diff (p= .025). Conclusions: After six months of intervention, the simple main effects suggest that AIT could improve vagal reactivation, assessed through HRR1diff, in patients that underwent CRT and were engaged in optimal medical treatment. Our findings also suggest that differences between groups in exercise capacity could be due to peripheral factors.Contexto: A insuficiência cardíaca (IC) é caraterizada por uma disfunção do sistema nervoso autónomo (SNA) que conduz a uma hiperativação simpática e desiquilíbrio parassimpático, culminando em disfunções centrais e periféricas. Nos casos mais avançados de IC, a terapêutica de ressincronização cardíaca (TRC) e o exercício parecem melhorar estas condições e, outros parâmetros clínicos e funcionais. O emergir de evidência robusta valoriza o treino intervalado aeróbio (TIA) em várias populações com IC, sabendo-se pouco acerca da sua influência sobre o SNA. Nesta análise, avaliámos os efeitos do TIA sobre a frequência cardíaca de recuperação (FCR), um indicador de ativação parasimpática. Todos os participantes possuíam uma fração de ejeção diminuída para ventrículo esquerdo, e colocaram o implante cardíaco seis dias antes do início da intervenção. O nosso objetivo foi o de avaliar se o TIA adicionado à TRC poderia melhorar a reativação vagal, medida pela diferença entre a frequência cardíaca pico e a FCR no primeiro minuto (FCR1dif). Métodos: Vinte e nove participantes idade 68 96 9 92; FEVE< 27 ; e o V O2Pico= 15 mL.kg-1.min-1) que estavam a receber tratamento médico otimizado (TMO), foram randomizados diferencialmente para os grupos de TIA e de controlo. O grupo de TIA realizou duas sessões de treino semanais, iniciando as mesmas com 10 minutos de aquecimento (50 a 60% da FC pico), seguido de quatro intervalos de 2 minutos (90 a 95% da FC pico) e 2 minutos de recuperação ativa (60 a 70% da FC pico). Depois de concluído o segundo mês, os intervalos de 2 minutos foram substituídos por intervalos de 4 minutos, enquanto os intervalos de recuperação por outros de 3 minutos. Recorrendo à prova de stress cardiopulmonar (PSCP), a qual foi efetuada até a capacidade volitiva máxima usando o protocolo de Bruce modificado, a FCR foi avaliada imediatamente a seguir ao mesmo. Resultados: A seguir aos seis meses de interven o, os efeitos principais foram significativos para V O2Pico (p= .010) e a duração da PSCP (p= .025). Contudo, depois de se testarem os simple main effects, apenas o grupo de TIA apresentou altera es significativas no per odo pós-interven o para: V O2Pico (p= .013), duração da PSCP (p= .020), frequência cardíaca de reserva (p= .035), pressão de pulso pico (p= .036), e FCR1dif (p= .025). Conclusões: Depois de seis meses de intervenção, os simple main effects sugerem-nos que o TIA pode melhorar a reativação vagal, medida pela FCR1dif a seguir ao exercício em pacientes que se encontram em TRC e TMO. Os resultados sugerem-nos ainda que as diferenças encontradas na capacidade funcional devem-se a fatores periféricos

Lower Limb Graduated Compression Garments Modulate Autonomic Nervous System and Improve Post-Training Recovery Measured via Heart Rate Variability

International Journal of Exercise Science 13(7): 1794-1806, 2020. Prior studies have examined the benefits of graduated compression garments (GCG) with regards to diverse exercise regimens; however, the relationship between GCG and the autonomic nervous system (ANS) has not been fully explored. The aim of this study was to examine Heart Rate Variability (HRV) trends—a proxy for ANS modulation—in response to donning GCG during a progressive overload training regimen designed to induce overtraining. Ten college-aged male novice runners were recruited for the 8-week crossover study. After three weeks of monitored free living, participants were randomized and blinded to an intervention group that donned a lower-body GCG during a two-week exercise regimen or a control group that donned a visually identical but non-compressive sham during identical training. No significant difference in HRV was calculated by the natural logarithm of the root mean square of successive RR-interval differences (lnRMSSD) between the 3-week free-living baseline and GCG intervention periods (P = 0.3040). The mean lnRMSSD was greater during the free-living phase and GCG intervention compared to the sham placebo (P \u3c 0.001 and \u3c0.001 respectively). With regard to the daily fluctuation of lnRMSSD, no significant differences were found between free-living and intervention (P = 1.000). Conversely, the intervention period demonstrated reduced daily fluctuation of lnRMSSD relative to the Sham placebo group (P = 0.010). These novel findings posit that post training use of a commercially available graduated compression garment in novice runners may be effective in counteracting some deleterious effects from overtraining while attenuating its effects on vagally-mediated HRV

Dynamic resistance training improves cardiac autonomic modulation and oxidative stress parameters in chronic stroke survivors : a randomized controlled trial

Stroke survivors are at substantial risk of recurrent cerebrovascular event or cardiovascular disease. Exercise training offers nonpharmacological treatment for these subjects; however, the execution of the traditional exercise protocols and adherence is constantly pointed out as obstacles. Based on these premises, the present study investigated the impact of an 8-week dynamic resistance training protocol with elastic bands on functional, hemodynamic, and cardiac autonomic modulation, oxidative stress markers, and plasma nitrite concentration in stroke survivors. Twenty-two patients with stroke were randomized into control group (CG, n=11) or training group (TG, n=11). Cardiac autonomic modulation, oxidative stress markers, plasma nitrite concentration, physical function and hemodynamic parameters were evaluated before and after 8 weeks. Results indicated that functional parameters (standing up from the sitting position (P=0.011) and timed up and go (P=0.042)) were significantly improved in TG. Although not statistically different, both systolic blood pressure (Delta=-10.41 mmHg) and diastolic blood pressure (Delta=-8.16 mmHg) were reduced in TG when compared to CG. Additionally, cardiac autonomic modulation (sympathovagal balance-LF/HF ratio) and superoxide dismutase were improved, while thiobarbituric acid reactive substances and carbonyl levels were reduced in TG when compared to the CG subjects. In conclusion, our findings support the hypothesis that dynamic resistance training with elastic bands may improve physical function, hemodynamic parameters, autonomic modulation, and oxidative stress markers in stroke survivors. These positive changes would be associated with a reduced risk of a recurrent stroke or cardiac event in these subjects2019CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão tem2017/21320-

Dynamic Resistance Training Improves Cardiac Autonomic Modulation and Oxidative Stress Parameters in Chronic Stroke Survivors: A Randomized Controlled Trial

Stroke survivors are at substantial risk of recurrent cerebrovascular event or cardiovascular disease. Exercise training offers nonpharmacological treatment for these subjects; however, the execution of the traditional exercise protocols and adherence is constantly pointed out as obstacles. Based on these premises, the present study investigated the impact of an 8-week dynamic resistance training protocol with elastic bands on functional, hemodynamic, and cardiac autonomic modulation, oxidative stress markers, and plasma nitrite concentration in stroke survivors. Twenty-two patients with stroke were randomized into control group (CG, n=11) or training group (TG, n=11). Cardiac autonomic modulation, oxidative stress markers, plasma nitrite concentration, physical function and hemodynamic parameters were evaluated before and after 8 weeks. Results indicated that functional parameters (standing up from the sitting position (P=0.011) and timed up and go (P=0.042)) were significantly improved in TG. Although not statistically different, both systolic blood pressure (Δ=-10.41 mmHg) and diastolic blood pressure (Δ=-8.16 mmHg) were reduced in TG when compared to CG. Additionally, cardiac autonomic modulation (sympathovagal balance-LF/HF ratio) and superoxide dismutase were improved, while thiobarbituric acid reactive substances and carbonyl levels were reduced in TG when compared to the CG subjects. In conclusion, our findings support the hypothesis that dynamic resistance training with elastic bands may improve physical function, hemodynamic parameters, autonomic modulation, and oxidative stress markers in stroke survivors. These positive changes would be associated with a reduced risk of a recurrent stroke or cardiac event in these subjects

Neurorehabilitation in Multiple Sclerosis: insights into fatigue and motor function

About this work This doctoral project aims to improve the overall knowledge on the effects of neurorehabilitation in People with Multiple Sclerosis (PwMS), by providing more insights on fatigue and the relationship between fatigue and motor functional aspects. The general introduction provides background information on the main topics of this doctoral project. In the first part, the specific disease characteristics of Multiple Sclerosis are described. In the second part, the current status of fatigue and motor impairment and a focus on the management are presented. Finally, the aims and outline thesis are reported. Four studies were conducted and reported in 4 different chapters. The first study provides information about the cardiac autonomic function during rest, postural changes and exercise and the relationship between autonomic modulation of heart rate and the perceived fatigue. The second study investigates the effect of an experimental rehabilitation protocol which combines aerobic training and task oriented exercises aimed to reduce fatigue and improve upper limb impairments and function. The third study provides information about preliminary effects of a high-intensity rehabilitative multimodal training protocol carried out on a treadmill aimed at improving mobility and balance. The fourth study shows the effectiveness of functional electrical stimulation on reducing falls, improving gait kinematics and promoting energy recovery. Lastly, general conclusions, including main findings and clinical implications, are provided at the end of the doctoral thesis