One of the most common questions we receive from patients in our Boulder Physical Therapy office is "what should I perform first, cardio or strength training, or should they be on separate days?" This is a great question because most endurance athletes are concurrently performing high volume endurance exercise along with strength training each week. Strength training has repeatedly been shown in the research to both improve performance and reduce an athlete's risk of future injury. Earlier studies showed aerobic training limited performance gains in strength, hypertrophy and power using resistance training. Conversely, newer research has shown significant strength gains are still possible with concurrent aerobic and resistance training.
A new research article in the Journal of Strength and Conditioning Research examined the impact of 4 different aerobic training conditions on a concurrent weight training program (Ratamess et al. 2016). The authors studied resistance trained men and put them through 4 different exercise protocols including treadmill running at 60% VO2 max for 45 minutes, 75% of VO2 max for 20 minutes, 90-100% VO2 Max for 5 sets of interval training, and finally 75% of VO2 max uphill (6-9% grade) for 20 minutes. Each of these aerobic protocols was followed 10 minutes later by whole body resistance training exercise. After each aerobic protocol, strength testing was compromised and the participants perceived each exercise as being harder than the control condition.
It is not known, if a longer rest period between aerobic and strength training or the long term effects of this training schedule would have changed the results. Endurance athletes are encouraged to allow for adequate recovery between aerobic and strength training workouts. In season athletes, should prioritize their endurance training but may focus more emphasis on their strength training workouts in the offseason.