Wednesday, October 31, 2012

Cardio & Weights - Mutual Exclusives or Synergists? Two New Studies Suggest: Cardio "Before" and After Workouts Offers More Benefits Than Downsides for Strength & Mass

Could "cardio" really be more than just a necessary evil on your way to a physique like this?
Yesterday testosterone booster (see "Capsaicin or 28-OB...") and today already the next "bro favorite": The never ending debate about "cardio and weights" (or should I rather write "cardio vs. weights"). If you are no newcomer to the SuppVersity you will be aware that this is not the first time, we are tackling this issue (e.g. "Cardio Before or After Weights?" or "Before, After or In-Between"). While most of the previous posts did however deal with the question of "How do I do the least damage to my resistance training, if I want to do cardio, as well". The two studies, I have in stock for you, today, would suggest that this question in and out of itself is quite nonsensical and that the "correct", or at least way more productive question must be: "How can I use cardio to promote my strength and mass gains?"

Curious? All right, let's take a look at what Tufano, Lundberg and their respective coworkers have in stock for you (Tufano. 2012; Lundberg. 2012)
  • The Tufano study confirms that doing cardio after an intense leg workout facilitates recovery- A question yet remains: What are the long term consequences? At least as long as you stick to doing just 20 minutes of cardio at 70% of your maximal heart rate, some cycling after a an eccentric leg workout (6 sets of 10 reps of eccentric leg extensions, specifically designed to induce maximal DOMS).

    Figure 1: Isometric strength after eccentric leg extensions in no, low and mean intensity cycling group expressed relative to pre values (Tufano. 2012).
    In the most recent study from the Department of Kinesiology at the Center for Sport Performance of the California State University the 10 women in the medium intensity cycling arm, who had cycled for 20 minutes at 70% of their individual heart rate recovered faster the muscle damaging workout than the women who went home without a "heavy cool down". What's actually even more astonishingly, though is that they also recovered faster than a third group of women who performed the 20min workout at only 30% of their VO2max.

    While there were no differences in pain scale or dynamic strength during the 4-day recovery phase, the isometric strength of the women in the 20min @ 70%VO2max arm of the study showed significant super-compensation effects on day 3 and day 4, so that Tufano et al. conclude:
    "Enhanced blood perfusion during moderate-intensity aerobic recovery, in conjunction with a short-term training effect, may enhance isometric strength after DOMS. Therefore, moderate intensity aerobic activity is suggested as a recovery method after multiple eccentric muscular actions." (my emphasis in Tufano. 2012)
    That certainly sounds as if another bro-scientific myth was tumbling and about to fall. Still, Tufano et al. are also right to point in the discussion of their results, that we need further research into the chronic effects of moderate-intensity aerobic 'recovery exercise' after resistance training - I mean, who guarantees that doing this after every workout week after week, month after month won't eventally turn against you?
What? You are not interested in recovery, anyway? All you want is grow and you doubt that the small increase is indicative of earlier supercompensation and that strength and grows would be two different pairs of shoes, anyway? Well, in that case here is another pro-cardio study:
  • The first important question this study answers is: How do you cycle with just one leg. You see the answer in the small inset of the image above.
    Aerobic before resistance training leads to minor increase in mTOR response and does not seem to hinder muscle gains! This one certainly flies in the face of what you may have been told by credible and less credible experts for your whole life. I mean, if anything, cardio was supposed to keep the gains lean. While the consensus is that it will diminish your gains -- right? Well, according to the latest study from the Mid Sweden University and the venerable Karolinska Institute and University Hospital in Stockholm this could turn out to be just another counterproductive bro-scientific myth: Skipping cardio altogether is not simply bad for your overall health an conditioning, as it would seem, it could even be beneficial for your gains, as well.

    To probe the effects of aerobic training on a whole host of hypetrophy and performance related factors, Tommy R. Lundberg and his colleagues recruited 9 physically active men (23+/-1 yr, 18+/-6 cm, and 75+/-6 kg) who "had been involved in recreational aerobic exercise two to three times per
    week and/or habitual RE one to two times per week for more than a year" (Lundberg. 2012) and had them perform a 45-min one-legged cycle ergometry exercise
    "The target load was 70% of the Wmax (cadence = 60 rpm). After 40 min, workload was in-creased by +20 W, and subjects were requested to continue until failure to maintain the prescribed cranking cadence, which typically occurred within 1–4 min (2 min 43 s)" (Lundberg. 2012)
    that was followed by 14 maximal concentric–eccentric knee extensions for each leg 6 h later (2 sets, 7 reps, 90s rest; starting with the AE+RE leg).
    "Thus, one limb was subjected to aerobic and resistance exercise (AE+RE), and the contralateral limb to resistance exercise (RE) only." (Lundberg. 2012)
    Before, as well as 15 and 180min minutes after the subjects underwent this training sessen, biopsies were taken and the glycogen content, the mRNA levels of vascular endothelial growth factor (EGF), peroxisome proliferator–activated receptor--gamma-coactivator-1 (PPAR-gamma), muscle RING-finger protein-1, atrogin-1 and myostatin, as well as the phosphorylated proteins mammalian target of rapamycin (mTOR), p70S6 kinase, ribosomal protein S6 and eukaryotic elongation factor were  measured. To ensure that no dietary factors would interfere with the results meals had been fully standardized on the day of the testing:
    "A standardized meal (pasta, tomato sauce, and juice) consisting of 2.21 g CHO/kg body weight, 22 g protein/kg bw, and 0.04 g fat/kg bw was provided at 8:00 p.m. the night before the experimental day. Subjects also had a standardized breakfast (1.01 g CHO/kg bw, 0.31 g protein / kg bw, and 0.24 g fat / kg bw) 1 h before the aerobic exercise session and lunch (2.02 g CHO/kg bw, 0.62 g protein/kg bw, and 0.49 g fat /kg bw) consumed 3 h before RE. These meals consisted of commercial energy drinks (Ensure Plus; Abbott Laboratories BV, Zwolle, The Netherlands). Water was allowed ad libitum at any time during the intervention." (Lundberg. 2012)
    As nice as it is to see a tightly controlled study, investigating a relevant topic and with trained healthy participant like this, I am really not a fan of these 'compare the left to the right leg' studies. And still, the fact that I am happy about any study into the whereabouts of different training modalities is neverthelsess not the only reason I am not going to beat a dead horse here.
    Figure 2: Unilateral peak concentric (CON) and eccentric (ECC) power (W) in knee extension and leg press during the experimental bout; data expressed relative to group baseline (Lundberg. 2012)
    The other and probably more relevant reason is that the data you see in figure 2 as surprising at it may seem  -- I mean who would have thought that the resistance training (RT) only leg would see a greater decline in force production during the experimental bout compared to baseline -- does not look like it had been skewed into this surprising direction by carry-over effect from one leg to the other or systemic factors such as central nervous system fatigue or the depletion of liver glycogen levels.

    In particular, we don't see anything of the expected drop in resistance training performance in the AE + RE leg due to the previous cardio workout. Even if it was only small, maybe statistically non-significant, common wisdom would dictate that it should be present! What we are seeing instead, however is a beneficial instead of a detrimental pre-conditioned effect in the 'cardio leg', of which you can hardly argue that it speaks in favor of the hypothesis that doing cardio must necessarily hamper your gains, if you allow enough time and food in between the morning and the evening workouts.

    It certainly looks as if the myth of the strength busting effects of any aerobic activity was about to fall and the corresponding protein expressions, the scientists measured before, 15min and 180min after the trial onyl support this notion.

    The image that emerges, when you take a closer look at the data in figure 3 is actually quite clear. At "pre" already, i.e. immediately before the resistance training part begins, the 'cardio leg' has and edge over the previously rested leg it won't lose in the course of subsequent hours. After all, despite the fact that at T = 180min some of the values have returned to baseline and/or the levels in the resistance training only leg have caught up, there is never a significant advantage of the resistance training only, over the aerobic + resistance training leg in the whole 3h period (respectively at the three intervals at which the biopsies were conducted).
    Figure 3: Selected markers of mitochondrial biogenesis and protein synthesis before during and 15, respectively 180min after the resistance training bout in the AE + RE and the RE only leg (a.u.; data adapted from Lundberg. 2012)
    Personally, I would still not consider these observations conclusive evidence of the superiority of aerobic + strength training in terms of its potential as a muscle builder (that it is a mitochondrial builder stands out of question). What is however undebatable (at least in this particular case), is that doing aerobics earlier in the day and lifting weight later in the day will not have a negative impact on either the performance or the measured markers of the exercise induced growth stimulus the resistance training session will have. It is rather, as the scientists point out that ...
    "[...] concurrent exercise elicited greater mTOR and p70S6K phosphorylation compared with RE. Although these differences were modest, if anything, they indicate that translational capacity was reinforced rather than compromised by the AE + RE intervention. In parallel, myostatin was suppressed for longer time in AE + RE, with no obvious sign of exacerbated protein degradation. Thus, in contrast to the posted hypothesis, it seems that concurrent AE + RE may enhance skeletal muscle anabolic environment." (my emphasis in Lundberg. 2012)
    I guess, there is actually little to add to that, despite the important warning that you must keep an eye on your overall training volume, in case you want to follow this approach. In the end this means that you are switching to a two-times-a-day regimen, which can take its toll not just on the ability of your muscles to adapt and recover, but more importantly on the ability of your central nervous system to cope with this additional stressor. 
Can I do HIIT instead? For the first study, the answer probably is no. It makes no sense to use HIIT training as a regenerative means after a workout. For the second study I would guess the answer is yes. After all, the aerobic morning workout was pretty strenuous and glycogen depleting, so I don't see any reason why a brief HIIT training in the 10-20min range would not yield the same if not even better priming effects (cf. "The Anabolic Effects of HIIT" )
Bottom line: I would not say that any of these studies gives you, who are hopefully interested to build muscle and maintain optimal health a free ticket to do as much cardio, whenever you want. What this compilation does yet do, is debunk the myth that you have to become a sedentary slob and discard the cardiovascular and obvious fat loss benefits the implementation of moderate amounts of aerobic training into your regimen will yield just because aerobics will necessarily comprimise your gains, let alone burn away your muscles.

Timed appropriately and used in moderate, instead of excessive amounts, some 'cardio' could in fact offer an overlooked means to provide a greater growth stimulus and promote faster recovery - and that next to all the health- and conditioning related benefits, I guess even the hardcore-bros won't doubt.

References:
  • Lundberg TR, Fernandez-Gonzalo R, Gustafsson T, Tesch PA. Aerobic exercise alters skeletal muscle molecular responses to resistance exercise. Med Sci Sports Exerc. 2012 Sep;44(9):1680-8.
  • Tufano JJ, Brown LE, Coburn JW, Tsang KK, Cazas VL, Laporta JW. Effect of aerobic recovery intensity on delayed-onset muscle soreness and strength. J Strength Cond Res. 2012 Oct;26(10):2777-82.