Influence of exercise order on the number of repetitions, oxygen uptake, and rate of perceived exertion during strength training in younger and older women.

The study investigated the effect of resistance exercise order on the number of repetitions, oxygen uptake (VO(2max)) and rate perceived exertion (RPE) in younger (YG: N = 10; 22 ± 2 years; VO(2peak) 42.2 ± 2.9 ml·kg(-1)·min(-1)) and older (EG: N = 8; 69 ± 7 years; VO(2peak)22.7 ± 2.5 ml·kg(-1)·min(-1)) women. The subjects performed 3 sets of each exercise until fatigue using 10 repetition maximum in 2 sequences of opposite order: (a) sequence A (SEQA): bench press (BP), machine shoulder press (SP), pulley triceps extension (TE); (b) sequence B (SEQB): TE-SP-BP. The VO(2) was assessed during the exercises, rest intervals, and 20 minutes after sequences (postexercise oxygen consumption [EPOC]). The number of repetitions decreased in both groups (p < 0.05) throughout sets. No difference (p > 0.22) was found between sequences for total VO(2) (exercise sequences + EPOC) in YG (SEQA = 25.41 ± 6.51 L vs. SEQB = 24.81 ± 4.08 L) and EG (SEQA = 26.45 ± 5.24 L vs. SEQB = 26.91 ± 4.62 L). In both groups, the VO(2) within the sequences was higher during BP when it was placed at the end of SEQB, the same occurring with TE in SEQA (p < 0.05). The VO(2) within sequences and RPE were higher in SEQB compared with SEQA (p < 0.05) in EG but not in YG. In conclusion, the exercise order did not affect total VO(2). The VO(2) within a given sequence was always lower when an exercise was performed first as compared with last regardless of the exercise order. Accumulated fatigue reflected by the VO(2) within sequences and RPE was influenced by the exercise order only in EG, suggesting that to prevent early fatigue, resistance training sessions in this group should preferably progress from large toward small-muscle group exercises.