Double Your Muscle, Maximize Your Endurance Gains: Train in the PM, not the AM, and Do Your Cardio Before Weights

Both, time and exercise order matter - at least when untrained subjects have trained for at least 12 weeks.

The debate about whether you should (a) do cardio and weights together and (b) whether you shall do either or both in the AM or PM for maximal muscle anabolism is older than the SuppVersity and has thus been addressed in many of the hitherto published approx. 2300 articles on suppversity.com.

The reason you should still read today's article, however, is that the approach to the topic is a bit different than usual, so that the study, which certainly leaves much to be desired (more on that in the bottom line), adds more practically relevant (which you cannot say about studies measuring the testosterone : cortisol ratio, for example) data.
Said data has been gathered over 24 weeks during which previously untrained, but healthy participants none of which belonged to either an extreme morning or evening chronotype or worked night shifts followed identical strength (S) and endurance (E) training regimen. The interesting and uncommon thing was was, that these workouts took place either in the AM (m, as in morning) or in the PM (e, as in evening) and were, on top of that, differently ordered (i.e. endurance (E) before strength (S) = E+S or strength (S) before endurance (E) = S+E) - according to cocker we should thus have 2x2 = four groups... and indeed, here they are:

• mE+S n=9, training in the morning, endurance before strength
• mS+E n=9, training in the morning, strength before endurance
• eE+S n=12, training in the evening, endurance before strength
• eS+E n=12, training in the evening, strength before endurance

In that, the workouts were identical with two workouts per week in the first and two-to-three workouts per week in the second 12-week-period (an additional session was added every two weeks so that all participants performed 5 training sessions in a 2-week period, the reasoning behind this was to "allow further progression in training adaptations" | Küüsmaa. 2016). Here are some details:

"The morning training groups (mE+S and mS+E) performed all training sessions between 6:30-10:00h, while the evening training groups (eE+S and eS+E) performed their training sessions between 16:30-20:00h. The training programs were identical for the E+S and S+E group independent of the training time, only the sequence of strength and endurance training was reversed. Endurance and strength training were combined into the one training session so that no more than a 5-10 minute break was allowed during the two training sections. The duration of the combined endurance and strength training sessions progressively increased from 60 to 120 minutes. All the training sessions were supervised.

Strength training consisted of exercises aimed at improving both maximal strength and muscle hypertrophy and was planned as a whole body periodized program with the main focus on knee extensors and flexors as well as hip extensors. Each training session consisted of three lowerbody exercises: bilateral dynamic leg press, seated dynamic knee extension and flexion. Four to five exercises were performed for other main muscle groups (lateral pull down, standing bilateral triceps push down, bilateral biceps curl, seated military press, or bilateral dumbbell fly, trunk flexors and extensors). Strength training was designed to improve muscular endurance in the first 4 weeks, which was performed as circuit training (intensity 40-70% of 1 RM). The subsequent 4 weeks (weeks 5-8) were designed to produce muscle hypertrophy (intensity 70-85% of 1 RM) and followed by 4 weeks (weeks 9-12) of mixed hypertrophic and maximal strength training (intensity 75-95% of 1 RM). A similar strength training program with slightly higher intensities was carried out also during the second 12 weeks of training" (Küüsmaa. 2016).

The cardio workouts were a mix of interval and continuous cycling on an ergometer. The sessions averaged from 30-50 minutes. Interval (85-100% of HRmax for 4x4 min, 4 min active rest in between) and continuous (65-80% of HRmax) training protocols were performed weekly.
As you'd expect it from a study like this, participants were tested for dynamic leg press 1 repetition maximum (1RM) and time to exhaustion (Texh) during an incremental cycle ergometer test both in the morning and evening before, during (12-week, see Figure 1) and after the 24-week intervention. all relevant information to address the practical value of training in the AM vs. PM and doing endurance before or after weights - a fact I would like to highlight (and applaud to), because that is unfortunately not the case in many other studies that lack practically relevant study outcomes, such as performance increases (here 1RM and Texh) and gains (here CSA values).

Figure 1: Study design and measurements. 1 RM = one repetition maximum in the dynamic leg press; Texh = time to exhaustion during the incremental cycling test; CSA = cross-sectional area; m = morning; e = evening (Küüsmaa. 2016)

I mean, who cares about acute (post workout) levels of exhaustion, 2-6h max protein synthesis or the testosterone to cortisol ratio and its diurnal rhythm if neither of these values can answer the question we are actually asking: Does it help you make extra strength, endurance or muscle gains? Not me (if you care, here's another of these studies, just out, speculating based on questionable markers of a "differential hormonal milieu" and free to read | Burley. 2016), because all these values are as reliable predictors of muscle gains as yesterday's weather forecast for Christmas... well, ok, maybe a bit better, but eventually it's results like those, Küüsmaa et al. present in their recent paper in Applied Physiology Nutrition and Metabolism, that matter:

• It's the Same (!) Time of the Day That Matters If You Want to Excel | Learn more about the effects of habitual training times on performance!

  1RM gains were similar in the morning (14-19%; p<0.001) and evening (18-24%; p<0.001); no sign time-of-day-effect
• CSA increased in all groups by week 24 (12-20%, p<0.01), however, during the training weeks 13-24 the evening groups gained more muscle mass; time-of-day main effect; p<0.05)
• Texh increased in all groups in the morning (16-28%; p<0.01) and evening (18-27%; p<0.001), just as the 1RM gains without effect of the exercise order, but with the data suggesting an advantage of doing cardio first (E+S) at 12 and 24 weeks

The overrated testosterone to cortisol ratio, the scientists assessed as well and even its diurnal rhythms, on the other hand, remained statistically unaltered by the training order or time at any point in the study. So that the study only confirms what I have said before to use the Bro's "holy yardstick of anabolism", i.e. the testosterone to cortisol ratio (T/C) after or in the vicinity of your workouts as an "anabolic guide" won't work, because it's simply not an acceptable predictor of any of the previously mentioned relevant training outcomes (strength, muscle size, and endurance).

Figure 2: Change (%) of the CSA of vastus lateralis (left), endurance performance in the AM (right, top) and PM (right, bottom) in the different training groups - left figure: *sign. (p < 0.05) within-group increase; # sign. different from controls; & sign. time-of-day main (TOD) effect | right figures: ¤ sign. between group differences as indicated; # sign. different from controls; $ sign. order main effect; sign. time-of-day (TOD) main effect (Küüsmaa. 2016).

The actual relevant messages of the study at hand have thus nothing to do with the T or C values or the T/C ratio. Rather than that, the present study "indicate[s] that combined strength and endurance training in the evening may lead to larger gains in muscle mass [in the 2nd part of the study, the PM training groups gained twice the amount of muscle the AM group did], while the E+S training order might be more beneficial for endurance performance development" (Küüsmaa. 2016). What is interesting, however, is that "training order and time seem to influence the magnitude of adaptations only when the training period exceeded 12 weeks (Küüsmaa. 2016; my emphasis) - that's an important observation from which I would like to segue right into the previously announced bottom line discussion of the few potential shortcomings of the study at hand.
References:

• Burley, Simon D., et al. "The Differential Hormonal Milieu of Morning versus Evening May Have an Impact on Muscle Hypertrophic Potential." PLOS ONE 11.9 (2016): e0161500.
• Küüsmaa, Maria, et al. "Effects of morning vs. evening combined strength and endurance training on physical performance, muscle hypertrophy and serum hormone concentrations." Applied Physiology, Nutrition, and Metabolism ja (2016).