title: Cardiac autonomic responses during upper versus lower limb resistance exercise in healthy elderly men.
abstract: OBJECTIVE
  To investigate the cardiac autonomic responses during upper versus lower limb discontinuous resistance exercise (RE) at different loads in healthy older men.
  
  
  METHODS
  Ten volunteers (65±1.2 years) underwent the one-repetition maximum (1RM) test to determine the maximum load for the bench press and the leg press. Discontinuous RE was initiated at a load of 10%1RM with subsequent increases of 10% until 30%1RM, followed by increases of 5%1RM until exhaustion. Heart rate (HR) and R-R interval were recorded at rest and for 4 minutes at each load applied. Heart rate variability (HRV) was analyzed in 5-min segments at rest and at each load in the most stable 2-min signal.
  
  
  RESULTS
  Parasympathetic indices decreased significantly in both exercises from 30%1RM compared to rest (rMSSD: 20±2 to 11±3 and 29±5 to 12±2 ms; SD1: 15±2 to 8±1 and 23±4 to 7±1 ms, for upper and lower limb exercise respectively) and HR increased (69±4 to 90±4 bpm for upper and 66±2 to 89±1 bpm for lower). RMSM increased for upper limb exercise, but decreased for lower limb exercise (28±3 to 45±9 and 34±5 to 14±3 ms, respectively). In the frequency domain, the sympathetic (LF) and sympathovagal balance (LF/HF) indices were higher and the parasympathetic index (HF) was lower for upper limb exercise than for lower limb exercise from 35% of 1RM.
  
  
  CONCLUSIONS
  Cardiac autonomic change occurred from 30% of 1RM regardless of RE limb. However, there was more pronounced sympathetic increase and vagal decrease for upper limb exercise than for lower limb exercise. These results provide a basis for more effective prescription of RE to promote health in this population.
authors.affiliation: Sao Carlos School of Engineering, Universidade de Sao Paulo, Sao Carlos, SP, Brazil.
authors.forename: Heloisa G
authors.initials: HG
authors.lastname: Machado-Vidotti
authors.affiliation: Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil.
authors.forename: Renata G
authors.initials: RG
authors.lastname: Mendes
authors.affiliation: Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil.
authors.forename: Rodrigo P
authors.initials: RP
authors.lastname: Simões
authors.affiliation: Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil.
authors.forename: Viviane
authors.initials: V
authors.lastname: Castello-Simões
authors.affiliation: Exercise Research Center, Physical Therapy Department, Universidade Federal de Sao Carlos, Sao Carlos, SP, Brazil.
authors.forename: Aparecida M
authors.initials: AM
authors.lastname: Catai
authors.affiliation: Sao Carlos School of Engineering, Universidade de Sao Paulo, Sao Carlos, SP, Brazil.
authors.forename: Audrey
authors.initials: A
authors.lastname: Borghi-Silva
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008875:Middle Aged; D034941:Upper Extremity / Q000502:physiology*