Low-intensity resistance exercise does not affect cardiac autonomic modulation in patients with peripheral artery disease

Effects of aerobic and combined training on pain-free walking distance and health-related quality of life in patients with peripheral artery disease: a randomized clinical trial

Background

Decreased walking ability in patients with peripheral arterial disease is often a clinical problem and limits the quality of life and daily activities of these subjects. physical exercise is important in this scenario, as it improves both the daily walking distance and the ability to withstand intermittent claudication related to the limitations of the peripheral disease.

Objectives

Our aim was to compare the effects of two types of exercise training (aerobic training and aerobic training combined with resistance exercises) on pain-free walking distance (PFWD) and health-related quality of life (HRQoL) in a sample composed of patients with peripheral artery disease (PAD).

Methods

Twenty patients with claudication symptoms were randomized to either aerobic control (AC) N= 9, or combined training (CT) N= 8, (24 sixty-minute sessions, twice a week). The total walking distance until onset of pain due to claudication was assessed using the 6-minute walk test and HRQoL was measured using the WHOQOL-bref questionnaire (general and specific domains) at baseline and after training. We used generalized estimating equations (GEE) to assess the differences between groups for the PFWD and HRQoL domains, testing the main group and time effects and their respective interaction effects. P values < 0.05 were considered statistically significant.

Results

Seventeen patients (mean age 63±9 years; 53% male) completed the study. Both groups experienced improvement in claudication, as reflected by a significant increase in PFWD: AC, 149 m to 299 m (P<0.001); CT, 156 m to 253 m (P<0.001). HRQoL domains also improved similarly in both groups (physical capacity, psychological aspects, and self-reported quality of life; P=0.001, P=0.003, and P=0.011 respectively).

Conclusions

Both aerobic and combined training similarly improved PFWD and HRQoL in PAD patients. There are no advantages in adding strength training to conventional aerobic training. This study does not support the conclusion that combined training is a good strategy for these patients when compared with classic training.

Impact of hypertension on arterial stiffness and cardiac autonomic modulation in patients with peripheral artery disease: a cross-sectional study

Objective:

To examine the impact of hypertension on cardiovascular health in patients with symptomatic peripheral artery disease and to identify factors associated with uncontrolled hypertension.

Methods:

A cross-sectional study including 251 patients with symptomatic peripheral artery disease (63.9% males, mean age 67±10 years). Following hypertension diagnosis, blood pressure was measured to determine control of hypertension. Arterial stiffness (carotid-femoral pulse wave velocity) and cardiac autonomic modulation (sympathovagal balance) were assessed.

Results:

Hypertension was associated with higher carotid-femoral pulse wave velocity, regardless of sex, age, ankle-brachial index, body mass index, walking capacity, heart rate, or comorbidities (ß=2.59±0.76m/s, b=0.318, p=0.003). Patients with systolic blood pressure ≥120mmHg had higher carotid-femoral pulse wave velocity values than normotensive individuals, and hypertensive patients with systolic blood pressure of ≤119mmHg (normotensive: 7.6±2.4m/s=≤119mmHg: 8.1±2.2m/s 120-129mmHg:9.8±2.6m/s=≥130mmHg: 9.9±2.9m/s, p<0.005). Sympathovagal balance was not associated with hypertension (p>0.05).

Conclusion:

Hypertensive patients with symptomatic peripheral artery disease have increased arterial stiffness. Arterial stiffness is even greater in patients with uncontrolled high blood pressure.

The influence of low-intensity resistance training combined with neuromuscular electrical stimulation on autonomic activity in healthy adults: A randomized controlled cross-over trial

Background:

Low-intensity resistance training (RT) combined with neuromuscular electrical stimulation (NMES) is one method of exercise to improve the deterioration of physical function. However, it is unclear whether low-intensity RT combined with NMES (RT + NMES) can be safely implemented.

Objective:

This study aimed to examine the influence of low-intensity RT + NMES on autonomic activity and cardiovascular responses in healthy adults.

Methods:

This study was an open-label, randomized controlled cross-over trial. The exercise intensity of isometric knee extension RT was set to 40% of the maximum voluntary contraction (peak torque). NMES was adjusted to a biphasic asymmetrical waveform with the frequency maintained at 50 Hz and a phase duration of 300 μs. The difference in the change in autonomic activity and cardiovascular responses was compared by assessing heart rate variability, blood pressure, and heart rate during RT and RT+NMES.

Results:

Twenty healthy male college students (mean age 21.0±0.6 years) participated in this study. The ratio of low- and high-frequency components of heart rate variability, systolic blood pressure, and heart rate increased during exercise in the RT and RT+NMES sessions (P<0.05). There were no significant differences in autonomic activity and cardiovascular responses throughout the sessions during RT and RT+NMES.

Conclusion:

In conclusion, our results demonstrated that low-intensity RT+NMES was safe and did not induce excessive autonomic and cardiovascular responses in healthy adults.

The Effects of Low Intensity Resistance Exercise on Cardiac Autonomic Function and Muscle Strength in Obese Postmenopausal Women

The present study examined the effects of a 12-week low intensity resistance exercise training (LIRET) regimen on heart rate variability (HRV), strength and body composition in obese postmenopausal women. Participants were randomly assigned to 12 weeks of either LIRET (n= 10) or non-exercising control group (n= 10). HRV, leg muscle strength and body composition were measured before and after 12 weeks. There were significant decreases (P < 0.05) in sympathovagal balance (LnLF/LnHF) and sympathetic tone (nLF) as well as significant increases (P < 0.05) in parasympathetic tone (nHF) and strength following LIRET compared to no changes after control. There were no significant changes in body composition after LIRET or control. LIRET may be an effective therapeutic intervention for improving sympathovagal balance and strength in obese postmenopausal women. Since obese postmenopausal women are at increased risk of developing cardiovascular diseases and physical disability, they could potentially benefit from LIRET.

The Impact of Walking Exercises and Resistance Training upon the Walking Distance in Patients with Chronic Lower Limb Ischaemia

Objective. The objective of this paper is to compare the impact of supervised walking and resistance training upon the walking distance in PAD patients. Materials and Methods. The examination involved 50 PAD patients at the 2nd stage of the disease according to Fontaine's scale. The participants were randomly allocated to two groups: one exercising on the treadmill (n = 24) and one performing resistance exercises of lower limbs (n = 26). Results. The 12-week program of supervised rehabilitation led to a significant increase in the intermittent claudication distance measured both on the treadmill and during the 6-minute walking test. The group training on the treadmill showed a statistically significant increase of the initial claudication distance (ICD) and the absolute claudication distance (ACD) measured on the treadmill, as well as of ICD and the total walking distance (TWD) measured during the 6-minute walking test. Within the group performing resistance exercises, a statistically significant improvement was observed in the case of parameters measured on the treadmill: ICD and ACD. Conclusions. The supervised rehabilitation program, in the form of both walking and resistance exercises, contributes to the increase in the intermittent claudication distance. The results obtained in both groups were similar.

A single bout of exercise with a flexible pole induces significant cardiac autonomic responses in healthy men

OBJECTIVES

Flexible poles can provide rapid eccentric and concentric muscle contractions. Muscle vibration is associated with a "tonic vibration reflex" that is stimulated by a sequence of rapid muscle stretching, activation of the muscle spindles and stimulation of a response that is similar to the myotatic reflex. Literature studies analyzing the acute cardiovascular responses to different exercises performed with this instrument are lacking. We investigated the acute effects of exercise with flexible poles on the heart period in healthy men.

METHOD

The study was performed on ten young adult males between 18 and 25 years old. We evaluated the heart rate variability in the time and frequency domains. The subjects remained at rest for 10 min. After the rest period, the volunteers performed the exercises with the flexible poles. Immediately after the exercise protocol, the volunteers remained seated at rest for 30 min and their heart rate variability was analyzed.

RESULTS

The pNN50 was reduced at 5-10 and 15-20 min after exercise compared to 25-30 min after exercise (p = 0.0019), the SDNN was increased at 25-30 min after exercise compared to at rest and 0-10 min after exercise (p = 0.0073) and the RMSSD was increased at 25-30 min after exercise compared to 5-15 min after exercise (p = 0.0043). The LF in absolute units was increased at 25-30 min after exercise compared to 5-20 min after exercise (p = 0.0184).

CONCLUSION

A single bout of exercise with a flexible pole reduced the heart rate variability and parasympathetic recovery was observed approximately 30 min after exercise.