The muscle groups that you pay attention to first during your workout grow and gain relatively more strength than the other muscle groups. Sports scientists at the Universidade Federal do Rio de Janeiro discovered this after doing an experiment on untrained men.
The Brazilians recruited 31 students from the Brazilian Navy Sergeants School and divided them into three groups: the LG-SM group, the SM-LG group and a control group.
The control group did nothing.
The LG-SM group did weight training for 12 weeks. During their workout the subjects started with the barbell bench press, then did lat-pulldowns, followed by the triceps extension machine and lastly a standing biceps curl with a straight bar. The subjects did four sets of each exercise. For the first four weeks of the experiment the subjects used weights at which they could perform 12-25 repetitions. Then they went up to weights at which they could manage 8-10 reps. Between sets they rested for two minutes.
The SM-LG group trained in exactly the same way. But they did the exercises in a different order. This lot first trained their biceps, then their triceps, then their lats and lastly their pecs.
The table below shows the gains in the strength for the different groups. It shows the changes in weight at which the subjects were able to make one rep. The figures marked with an asterisk show the increases that were statistically significant.
The researchers also made scans of the subjects’ arms and used them to measure the increase in circumference of the biceps and triceps. There’s a scan at the top of the page.
“Based on the 1RM strength gains and effect size results of the current study, it appears exercises that are particularly important for the training goals of a program should be placed at the beginning of the training session, whether or not it is a large or a small muscle group exercise”, the researchers conclude.
INFLUENCE OF EXERCISE ORDER ON MAXIMUM STRENGTH AND MUSCLE THICKNESS IN UNTRAINED MEN
Traditional exercise order dictates large muscle group or multijoint exercises should be performed before small muscle group or single joint exercises. The purpose of this study was to examine the influence of exercise order on strength and muscle thickness (MT) in untrained men after 12 weeks of linear periodized resistance training. The participants were randomly assigned into three groups. One group began with large and progressed toward small muscle group exercises (LG-SM) while another started with small and advanced to large muscle group exercises (SM-LG). The exercise order for LG-SM was bench press (BP), lat pull-down (LPD), triceps extension (TE), and biceps curl (BC). The order for the SM-LG was BC, TE, LPD, and BP. The third group served as a control group (CG). Training frequency was two sessions/week with at least 72 hours between sessions. One repetition maximum (1RM) for all exercises, biceps and triceps MT (assessed by ultrasound techniques) were collected at baseline and after 12 weeks. After 12 weeks, all exercises for both training groups presented significant 1RM strength gains when compared to CG with exception of BC in LG-SM. Between baseline and post training, all exercises for both training groups presented significant strength gains with exception of BC in LG-SM and BP in SM-LG. Triceps MT for both training groups were significantly higher when compared to the CG, but with no significant differences between them (p > 0.05). Significant differences in MT from pre- to post-training were found only for the SM-LG group (p < 0.05), while the biceps MT presented significant differences only between LG-SM and CG (p < 0.05), Effect size data demonstrated differences in 1RM and triceps MT based on exercise order. In conclusion, if an exercise is important for specific training goals, it should be performed at the beginning of the training session, whether or not it is a large or a small muscle group exercise. Source: http://www.jssm.org/vol9/n1/1/v9n1-1abst.php