2. Sport Science: The Brain-Body Connection
Mark D. Stephenson, MS, ATC, CSCS,*D, TSAC-F

3. Brain-Body Axis Interoception Influences Autonomic regulation
Processing of visceral-afferent neural signals by the CNS (Schulz, & Vögele, 2015)
Involved in homeostasis & self-regulation
Influences Autonomic regulation
Autonomic Nervous System (ANS)
Heart Rate Variability

4. Brain-Body Axis Vagus Nerve Parasympathetic influence of the SA node
Efferent & Afferent pathway
Parasympathetic innervation of the heart, lungs, gastrointestinal tract (other abdominal visceral organs)
Parasympathetic influence of the SA node
Vagal stimulation decreases HR
Sympathetic stimulation increases HR

5. Interoception Insula Cortex Processing of internal bodily signals
Integration of mental map and sensory information to create sense of self

6. Response to perceived threat
Perception
Brain’s response to a perceived threat
Sensory input
Visual
Auditory
Environmental
Touch/sensation
Emotional
Sensory Input
Perception of threat
Response to perceived threat

7. Autonomic Nervous System (ANS)
Vagal (Parasympathetic)
Decreases Heart Rate
Inhibit sympathetic nerve activity
Vagal Inhibition (Sympathetic)
Increase sympathetic outflow to SA node
Increases heart rate
Parasympathetic response inhibits sympathetic nerve activity necessary for responding to threat (Fight or flight).
Sympathetic activation relases norepinephrine (NE) and decrease K leakage while slowing Ca and Na uptake.

8. Electrophysiology P wave QRS Complex R-S segment R-R
Action potential (depolarization)
QRS Complex
Repolarization of ventricles
R-S segment
Indicator of immune dysfunction
R-R
Time (ms) between the peak of R to the peak of the next R (HRV)

9. Heart Rate Variability (HRV)
Measure of Vagal Function
Link between physiological and cognitive function
Prefrontal neural function
High Variability – Recovery
Low Variability - Stress

10. HRV Calculated 972ms – 888ms = Δ 84ms HRV = 84
Average of last 300 consecutive beats = HRV
HRV average changes with each beat

11. HRV Frequency Domains

12. HRV Frequency Domains High Frequency (HF) – 0.15 - 0.40 Hz
Governed exclusively by Parasympathetic effects
Driven by respiration (specific to depth of respiration)
Low Frequency (LF) – Hz
Both sympathetic and Parasympathetic modulation
Predominately Sympathetic
Very Low Frequency (VLF) – 0.01 – 0.04 Hz
Governed exclusively by Sympathetic effects
LF/HF Ratio
Metric of sympathetic-parasympathetic balance

13. HRV Frequency Domains
Parasympathetic Dominance
Sympathetic Dominance

14. Cognitive Function Prefrontal Cortex Motor Cortex
Dorsal Lateral Pre-Frontal Cortex (DLPFC)
Motor Cortex

15. Direct Current (DC) Potential
DC Potential – Signaling from cell-to-cell (mV)
Relaxed – (+) voltage
Stress – (-) Voltage
Strength of signal
Chronic Stress – Long-term decrease in voltage
Acute stress – Temporary decrease in voltage
Dimmer Switch Theory
Increase time to shift from (+) to (-)
DC potential is a shift after receiving stimulus to a negative voltage
Chronic stress results in an increase in time to shift to a negative voltage.

16. Cellular DC Potential

17. Stress Reaction

18. HPA Axis Hypothalamus-Pituitary-Adrenal Axis
Maintain Homeostasis (endocrine balance)
Response to stress
CRF regulates HPA axis
Regulated at the level of the hypothalamus
Glucocorticoids released from adrenal gland
Mediated by ANS
Sympathetic-parasympathetic

19. HPA Axis

20. Brain-Body Connection
Stimulus
Efferent-Afferent signal
Exteroceptive -Interoceptive
Vagus Nerve
Parasympathetic
Sympathetic
DC Potential
(+) mV RELAXED
(-) mV STRESS
HPA
Increase Endocrine response
Decrease Endocrine response

22. Monitoring Zephyr, Haldago Omegawave, BioForce, ithlete, Biofeedback
Smart Phone Apps

23. Summary Brain-Body Connection HRV + DC Potential = State of Readiness
Recovery = Optimal State of Readiness
The brain and body cannot be separated
Both must be monitored

24. Mark D. Stephenson, MS, ATC, CSCS,*D, TSAC-F
Questions?
Mark D. Stephenson, MS, ATC, CSCS,*D, TSAC-F