Sympathetic Nervous System
Conditions
Keywords
skin sympathetic nerve activity, concurrent training, resistance training, autonomic nervous system
Brief summary
This study examines how the body's stress (sympathetic) nervous system responds to 8 weeks of either strength training alone or strength training combined with endurance (treadmill running) training in previously untrained young men. Skin sympathetic nerve activity, a noninvasive marker of sympathetic nervous system activity, is measured before and after training, along with muscle strength, jumping ability, and heart rate variability. The study investigates whether changes in sympathetic nervous system activity are associated with changes in strength and jumping ability, and whether this relationship differs between men who perform strength training alone versus those who combine strength and endurance training.
Detailed description
This study examined how the body's stress (sympathetic) nervous system responds to 8 weeks of either strength training alone or strength training combined with endurance (treadmill running) training in previously untrained young men. Skin sympathetic nerve activity, a noninvasive marker of sympathetic nervous system activity, was measured before and after training, along with muscle strength, jumping ability, and heart rate variability. The study found that in men who did strength training only, those whose sympathetic nervous system activity increased the most also gained the most strength and jumping ability. This relationship was not seen, and in some cases reversed, in men who combined strength training with endurance training. The findings suggest that adding endurance exercise changes how the nervous system adapts to a strength training program, alongside the well-documented reduction in strength gains seen with combined training (the "interference effect").
Interventions
OTHERStrength-only training
Supervised resistance exercise comprising weighted calf raises, back squats, countermovement jumps, and weighted lunges, performed on a Smith machine three times weekly for 8 weeks.
OTHERConcurrent training
performed on a Smith machine three times weekly for 8 weeks.
Sponsors
Beijing Sport University
China institute of sport science
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Caregiver)
Masking description
Participants and trainers could not be blinded to group allocation given the nature of the exercise interventions. All autonomic, neuromuscular and reflex outcome data were acquired, processed and statistically analyzed by investigators blinded to group allocation, using coded, de-identified records until analyses were complete.
Intervention model description
In the concurrent training arm, resistance exercise was always performed before endurance exercise within each session (a strength-priority sequence).
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy young men * No hypertension or cardiovascular/vascular disease * No migraine or neurodegenerative disease * No smoking or alcohol use * No prior structured exercise training * No musculoskeletal injury * Willing to abstain from caffeine, alcohol, and strenuous exercise for 24 hours before testing
Exclusion criteria
* Hypertension or cardiovascular/vascular disease * Migraine or neurodegenerative disease * Current smoking or alcohol use * Prior structured exercise training history * Musculoskeletal injury precluding resistance or endurance exercise
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| skin sympathetic nerve activity (aSKNA) | Baseline and 8 weeks | Average rectified voltage of skin sympathetic nerve activity recorded noninvasively via the neuECG method. |
| Change in one-repetition maximum (1RM) back squat | Baseline and 8 weeks | — |
| Change in countermovement jump (CMJ) height | Baseline and 8 weeks | — |
Secondary
| Measure | Time frame |
|---|---|
| Change in CMJ peak velocity | Baseline and 8 weeks |
| Change in CMJ peak power | Baseline and 8 weeks |
| Change in SKNA burst duration | Baseline and 8 weeks |
| Change in SKNA burst amplitude | Baseline and 8 weeks |
| Change in SKNA burst total area | Baseline and 8 weeks |
| Change in CMJ peak force | Baseline and 8 weeks |
Countries
China
Outcome results
None listed