Aerobic exercise and resistance exercise both have their respective merits. While there are some that love one and hate the other, many individuals incorporate both modes of exercise into the one session. What’s more, there’s a bit of debate as to how to order the different exercise modes; namely, weights first – then aerobics or vice versa. A recent study published in the popular and prestigious Journal of Strength and Conditioning Research set out to answer the question.
To test whether it’s best to do resistance or aerobic exercise first, the researchers took a group of female college students that happened to be inactive. As one would expect, the group was split into two, with one doing aerobic exercise before resistance exercise, and the other doing the reverse. The study ran for 8 weeks and outcome measures included changes in VO2max, strength and body composition. As for the specifics of the aerobic and resistance exercise; an aerobic session consisted of 30 minutes of exercise at 70-80% maximal heart rate, while a weights session consisted of 3 sets of 8-12 repetitions for a total of 5-6 different exercises using a load equal to 90-100% of 10 repetition maximum. Both groups trained 4 days a week.
The good news is that females in both groups improved their strength in chest press, leg press as well as experiencing an improvement in V02max. These improvements came with a boost in muscle mass as well. However, the interesting finding was that neither group lost any significant body fat and more importantly improvements in fitness and strength were not affected by the order in which resistance or aerobic exercise was performed.
It must be noted, however, that a major limitation of the study was that it used college-aged females who were inactive. It’s not possible to say whether the same results would manifest if the study had used experienced female trainers or whether results would be different with males; trained or untrained.
Many people believe that its best to do resistance exercise first as it depletes glycogen levels so that when one hits the treadmill, their predominantly burning fat. This particular study did not include any specific measures of fat oxidation - making it impossible to determine if subjects burned more fat when performing aerobic exercise after lifting weights. But if there’s one thing that science can teach us - it’s that despite how good a theory sounds, it remains to be proven until it's tested.
Davitt PM, et al. The effects of a combined resistance training and endurance exercise program in inactive college female subjects: does order matter? Journal of Strength and Conditioning Research. 2014;28(7):1937-1945.