OBJECTIVES: This study investigated indirect measures of post-exercise parasympathetic reactivation (using heart-rate-variability, HRV) and sympathetic withdrawal (using systolic-time-intervals, STI) following upper- and lower-body exercise. DESIGN: Randomized, counter-balanced, crossover. METHODS: 13 males (age 26.4+/-4.7years) performed maximal arm-cranking (MAX-ARM) and leg-cycling (MAX-LEG). Subsequently, participants undertook separate 8-min bouts of submaximal HR-matched exercise of each mode (ARM and LEG). HRV (including natural-logarithm of root-mean-square-of-successive-differences, Ln-RMSSD) and STI (including pre-ejection-period, PEP) were assessed throughout 10-min seated recovery. RESULTS: Peak-HR was higher (p=0.001) during MAX-LEG (182+/-7beatsmin(-1)) compared with MAX-ARM (171+/-12beatsmin(-1)), while HR (p<0.001) and Ln-RMSSD (p=0.010) recovered more rapidly following MAX-ARM. PEP recovery was similar between maximal bouts (p=0.106). HR during submaximal exercise was 146+/-7 (LEG) and 144+/-8beatsmin(-1) (LEG) (p=0.139). Recovery of HR and Ln-RMSSD was also similar between submaximal modalities, remaining below baseline throughout recovery (p<0.001). PEP was similar during submaximal exercise (LEG 70+/-6ms; ARM 72+/-9ms; p=0.471) although recovery was slower following ARM (p=0.021), with differences apparent from 1- to 10-min recovery (p</=0.036). By 10-min post-exercise, PEP recovered to baseline (132+/-21ms) following LEG (130+/-21ms; p=0.143), but not ARM (121+/-17ms; p=0.001). CONCLUSIONS: Compared with submaximal lower-body exercise, HR-matched upper-body exercise elicited a similar recovery of HR and HRV indices of parasympathetic reactivation, but delayed recovery of PEP (reflecting sympathetic withdrawal). Exercise modality appears to influence post-exercise parasympathetic reactivation and sympathetic withdrawal in an intensity-dependent manner. These results highlight the need for test standardization and may be relevant to multi-discipline athletes and in clinical applications with varying modes of exercise testing.