Exercise Order Reloaded: Testosterone Advantage of Doing Weights First Does Not Persist over 24 Week Study Period ➲ Strength Gains Identical, But GH Difference is Suspicious

Could the "wrong" exercise order be holding you back?

If you take a look at the SuppVersity articles with the keyword"exercise order" (click here to do that now), you will probably find "good" arguments for both: Doing cardio before and  doing cardio after weights - this begs the question, whether it is merely a question of personal preference, doesn't it?

I, for my part, have done both in the past and didn't notice much of a difference. For mere time reasons I do my cardio completely separate from my workouts, but in general, I would probably do longer 20min+ low intensity steady state cardio after the workouts. Not the least for the beneficial effects of very low intensity exercise on both metabolic and performance markers of recovery (Corder. 2000).
If we take a look a the results of a recent study by Moritz Schumann et al., these acute recovery effects may yet have about as little effect on the real-world outcome of your training sessions as the temporary reduction in testosterone the researchers from the Public University of Navarra, the Edith Cowan University and the University of Connecticut observed in those 12 of their ca. 30 years old, ca. 179 cm tall and ca. 79 kg heavy male, recreationally active study participants who had been randomized to the "cardio before weights" (E + S: endurance before strength training) group. It goes without saying that the exercise prescriptions for the E+S and S+E groups were identical:

Additional read: "Cardio&Strength What Do I Do First?" Plus: Could the Answer Be Sex-Specific?" | more

"During the first 12 weeks of training, the subjects per formed according to their corresponding training group either 2x[1E + 1S] or 2x[1S + 1E] per week.

During the second 12 weeks, the frequency was increased so that two combined training sessions were performed in every 1st and 4th week and three combined training sessions in every 2nd and 3rd week (i.e., 2x[1E + 1S] or 2x[1S + 1E] or 3x [1E + 1S] or 3x[1S + 1E], respectively). " (Schumann. 2014)

For the "E" in "E + S", the subjects cycled on a regular ergometer at an intensity that was controlled by heart rate zones determined from subjects’ individual aerobic and anaerobic threshold obtained during the baseline measurement at week 0 and 24. 

Figure 1: Overview of the 24-week study protocol (Schumann. 2014)

They were asked to maintain a constant pedaling frequency at about 70–80 rpm during each training session, while the magnetic resistance of the ergometer was used to achieve the prescribed cycling intensity:

"The endurance program consisted of both steady-state and interval exercise sessions while the intensity was progressively increased from low (below the aerobic threshold) to high (above the anaerobic threshold) throughout both 12-week periods." (Schumann. 2014)

If you add the 30-50 minutes it took the subjects to complete the periodized (circuit training 2-4 sets of all exercises at 15-20 reps  40-60% in week 1-2; 2-5 sets of 8-10 reps @80-85% during the rest of the study) strength training routine, that consisted of exercises for the lower and upper body, i.e.

• lower body -bilateral dynamic leg press, as well as both bilateral (weeks 1–7 and 13–18) and unilateral (weeks 8–12 and 19–24) dynamic knee extension and flexion -
• upper body - vertical shoulder press and lat pull down, as well as exercises commonly used to improve trunk stability -,

to the 30–50 min of cardio the subjects performed on each of their three weekly workouts, the total duration of the workouts would be 60–100 min for each combined training session.

Post workout testosterone = statistically significant, practically irrelevant difference

In view of the fact that the total training time, the exercises and the workout frequency were identical, the previously mentioned inter-group differences in post-workout testosterone are attributable to the exercise order - irrespective of whether they were mediated by a reduced performance in the strength training session or whatever crazy counter-evidence you were just about to mention in the comments ;-)

Figure 2: Serum testosterone concentrations during loading and recovery before (a) and after (b) the combined training (left); changes in basal serum markers after 24 weeks of training (right; Schumann. 2014).

If you take a closer look at Figure 2, you will also notice that the initial difference in post-workout testosterone levels (left) is lost over the course of the 24-week study period. Against that background and in view of the inter-mediate increase in testosterone in the E+S vs. S+E group, it is not surprising that the relevant outcomes, i.e. the 1-RM, the increase in maximal voluntary contractile force (MVC) and the gain in aerobic power didn't differ between the S+E vs. E+S groups.

Figure 3: Rel. change in performance parameters within the 24 week study period (left); acute responses and recovery of maximal isometric leg press force (MVcmax) before (a) and after (b) the combined training (right; Schumann. 2014).

What is interesting though and may even be interpreted as evidence to support my previous suggestion to do "cardio after weight" for its beneficial effects on recovery is the slightly more pronounced decrease in creatine kinase in the S+E group (see Figure 3). Even if we take into consideration that CK is not the reliable marker of muscle damage everyone says it was (Chrismas. 2014), the relative CK values may still serve as a proxy of recovery, which could be enhanced with cardio after weights.
Reference:

• Chrismas, Bryna CR, et al. "Reproducibility of creatine kinase: how useful is this measurement tool?." International Journal of Exercise Science: Conference Proceedings. Vol. 10. No. 1. 2014.
• Corder, Keith P., et al. "Effects of active and passive recovery conditions on blood lactate, rating of perceived exertion, and performance during resistance exercise." The Journal of Strength & Conditioning Research 14.2 (2000): 151-156.
• Schumann, Moritz, et al. "The order effect of combined endurance and strength loadings on force and hormone responses: effects of prolonged training." European journal of applied physiology (2014).
• West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.