(1) Background: The present study attempted to determine and compare the vascular impact of traditional and functional resistance training on arterial stiffness. (2) Methods: The present study was conducted in 29 untrained healthy young males aged 18–29 years who were randomly divided into two groups, namely traditional resistance training (TRT, n = 15) and functional resistance training (FRT, n = 14). All subjects underwent numerous tests before and after the 6-week training such as body composition, cardio-ankle vascular index (CAVI), blood pressure, heart rate, and maximal strength. The exercise training comprised whole-body strength training exercises 3 days a week for 6 weeks. The total training volume and number of sets (4–5 sets) were kept constantly similar in each group. The TRT group completed 4–5 sets of 8–12 repetitions [70% of 1 repetition maximum (1RM)], whereas the FRT group completed 4–5 sets of 15–22 repetitions (40–50% of 1RM). (3) Results: After the 6-week intervention, lean body mass (TRT: Pre: 59.5 ± 5.4 kg; Post: 60.4 ± 4.9 kg vs. FRT: Pre: 57.7 ± 6.7 kg; Post: 58.8 ± 5.9 kg) significantly increased in both TRT and FRT groups, whereas body fat (TRT: Pre: 18.8% ± 5.8%; Post: 16.5% ± 5.3% vs. FRT: Pre: 16.7% ±4.6%; Post: 15.3% ± 4.7%), R-CAVI (TRT: Pre: 6.2 ± 0.6 m/sec; Post: 5.7 ± 0.6 m/sec vs. FRT: Pre: 5.9 ± 0.5 m/sec; Post: 5.3 ± 0.6 m/sec), and L-CAVI (TRT: Pre: 6.2 ± 0.6 m/sec; Post: 5.7 ± 0.6 m/sec vs. FRT: Pre: 6.0 ± 0.6 m/sec; Post: 5.4 ± 0.6 m/sec) decreased. Additionally, the maximal strength increased significantly in both the groups (p < 0.01). However, no significant difference was observed between the two groups. (4) Conclusions: A similar training volume of TRT and FRT with unstable surface significantly decreased body fat and arterial stiffness and improved lean body mass and maximal muscle strength in young men.