Friday, January 2, 2015

How Much Cardio Messes W/ Your Weight Training Results Depends on Recovery Times: Weight + Cardio in One Session vs. AM + PM Training vs. Doing Each on One Day

Who would have thought that? After dozens of contradictory and highly inconclusive studies, this could finally be the one study designed to yield the answers to many of our questions about the effects of concomitant endurance and strength training.
A "concomitant trainer" that's my way of labeling someone who performs both strength and endurance workouts. Someone like the fifty-eight amateur rugby players who volunteered for an experiment ([mean ± SE] age, 25.5 ± 0.4 years, ranging from 21 to 28 years) scientists from the French federation of rugby union conducted last year. All were free from severe injuries for the last year. Their practice volume was ~4 to 5 hrs per week with only minimal experience in resistance training.

For the whole seven-week training period, the volunteers were randomly assigned to one of the five experimental groups with three concurrent strength and endurance training groups, one strength-training group and one control group.
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The entire experiment was performed during the summer off-season. Therefore, subjects performed only one of the five training programs. They were asked to restrict fatiguing efforts at least two days before each test session and were also advised to maintain their normal dietary intake throughout the study. No food supplement was administered during all the protocol duration.

Speaking of which, the experiment itself was 10 weeks long with the first week dedicated to familiarization with all equipment and testing procedures, the second week involved the initial tests, the next seven weeks the training programs and the last week the final tests. The independent variable was the treatment effect of five different 7-week training programs with one control group (CONT), one strength only training group (STR) and three concurrent strength and endurance training groups. The latter consisted of two sequences a week of each quality.
  • Aerobic Training: Aerobic exercises included three 6-min sets of high intensity 15 s/15 s interval training on a field. Subjects, wearing cleats, alternated 15 s runs at 120% of their individual MAV with 15 s of passive recovery.

    A 5-min warm-up, consisting of moderate to cruising runs, preceded each aerobic training session. Subjects wore an individual heart rate monitor (Polar Electro Oy, Kempele, Finland) during each session in order to assess the cardiac workload and to regulate the distance to cover during the 15 s efforts.

    Distance to cover for the next sessions was higher if heart rate was lower than the rate of 90% of the maximal heart rate.
  • Strength training: Every session began with a warm-up focused on abdominals/core training. Strength-training sessions consisted of 3-4 sets of 3-10 RM of the lower limbs (half squat - HS and leg press . LP) and upper limbs (bench press BP and BR).

    Concomitant Training: Cardio Before or After Weights? Cardio First Triggers 916% Increase in Growth Hormone. Plus: 7x Higher Testosterone & 3x Higher IGFBP-3 Peaks | read more
    Training was divided into three periods during which the intensity progressively increased. The first period (weeks 1-2) aimed to prepare participants for a maximal strength training by performing 3 or 4 series with 10 repetitions a set at 70% of the 1RM. The second (weeks 3-5) and the third periods (weeks 6–7) were designed to increase maximal strength performing 3 or 4 series with 6 and 3 repetitions a set close to 80 and 90% 1RM, respectively.

    The 1RM was checked each week in order to regulate strength workload. Each set of HS, done on a guided machine, was immediately followed by plyometric jumps. Also, sets of LP were combined with eccentric exercises on hamstring muscles. Rest between sets ranged from 2 to 3 min according to strength-training recommendations (hypertrophic vs. maximal strength),

    All contractions during upper limbs exercises were performed in isoinertial conditions with free weights. The ones done during lower limbs exercises were performed with specific Cybex guided machines (Medway, USA). Exercises were randomized during each training session, alternating lower- and upper body tasks.
With the workouts being identical (see above), the only difference between the C-0h, C-6h and C-24h groups was the recovery delay between strength and endurance sequences. In all groups, strength training was always performed first and was followed by endurance training. Altogether the groups did thus look as follows:
  • C-0h - cardio training was done immediately after resistance training - 0h rest,
  • C-6h - strength in the AM, cardio training in the PM - 6h rest or
  • C-24h - strength on day 1, cardio training on day 2 - 24h rest
STR group which served as an active control for the "maximally possible" strength gains (without concomitant endurance exercise) only completed the strength sequences.
Figure 1: Rel. changes (%) from baseline for the strength parameters maximal voluntary contractions (MVCs), test exercises and counter-movement jumps (CMJ | Robineau. 2014)
The training routines were planned to ensure that there were at least 72h between the two strength sequences for all training groups (C-0h, C-6h, C 24h and STR). The CONT group, which served as a passive control did not train during the entire duration of the experimental protocol and only performed pre- and post-tests. Accordingly, the training effects had to be judged against both the CONT and the STR group, to answer the questions: (1) Were there any significant gains in strength and endurance performance; and (2) Were there significant disadvantages in the concomitant training groups when it comes to strength gains compared the STR (strength only) group?
Before you are asking about body fat and lean mass data: The scientists did not measure the effects on the body composition of their subjects. Quite a pity, because I suspect that this could well have tipped the scale in favor of the concomitant training. Sillanpää, et al. (2009), for example, found that a combined resistance + endurance training protocol lead to 110% more body fat loss in middle-aged and older women. Similar improvements in body fat loss were observed in middle-aged women on a endurance + resistance training protocol that would resemble the C-24h regimen in the study at hand (Park. 2003). Without at least some body impedance data from the study at hand, it's yet just an educated guess that we would have seen improvements in body composition - specifically increased fat loss - in all of the C-groups.
Figure 2: It should not come as a surprise that trained football players don't get an endurance benefit from doing resistance training (Robineau. 2014) - Maybe you remember this fact, the next time you are huffing and puffing, because you had to run to catch the train or realize you can't keep up w/ your 5-year old, bro?
As the data in Figures 1-2 tells you, there were such differences. As the scientists point out, gains in maximal strength for bench press and half squat were lower in C-0h compared to C-6h, C-24h and STR.

Moroever, the maximal voluntary contraction (MVC) during isokinetic knee extension at 60°·s-1 was likely higher for C-24h compared with C-0h, and the changes in maximal voluntary contractile force (MVC) at 180°·s-1 were likely higher in C-24h and STR than in C-0h and C-6h.
On the other hand, differences in the training-induced gains in isometric MVC for C-0h, C-6h, C-24h and STR were unclear and the VO2peak, a measure of aerobic conditioning increased only in those groups who actually did cardio training, i.e. C-0h, C-6h and C-24h.

In that, it is interesting to observe that the long(er) rest periods between endurance and strength training in the C-24 group lead to significantly greater increases in VO2peak in the subjects in said group compared to those who had been randomized to the C-0h and C-6h (AM, PM) group. With respect to the mean strength gains, on the other bench, the half-squat and the bench row, though, the AM-PM, i.e. the C-6h protocol appears to offer a non-significant advantage that stands in contrast to the ameliorated gains in maximum voluntary contractile force in this group. This part of the results is thus in fact "unclear" (Robineau. 2014).
So no concomitant training? Bullsh*t! Firstly, if you can do "cardio" and "weights" on separate days, there is no problem at all. Secondly, if you can train only thrice a week, but pack in morning cardio + a strength training session in the PM, that's unlikely to hamper your gains significantly - specifically if you replete the glycogen stores and consume enough protein in the time between the AM+PM workout. Thirdly, even if you cannot do either cardio and weights on separate days or AM + PM sessions, the most significant result of the study at hand is that the cardiovascular disad- vantage of doing no cardio at all is significantly larger than the marginally reduced MVC gains if you do cardio and weights in one session. So what? Get your ass off that bench and move it ;-)
Bottom line: Overall, the study at hand proves that the interference between cardio and strength training depends on the recovery delay between the two sequences. That's practically news and has not been tested by any previous studies, which implies that "[d]aily training without a recovery period between sessions (C-0h) and, to a lesser extent, training twice a day (C-6h), is not optimal for neuromuscular and aerobic improvements." Accordingly, the Julien Robineau et al. are right, when they recommend: "Fitness coaches should avoid scheduling two contradictory qualities, with less than 6-hours recovery between them to obtain full adaptative responses to concurrent training" (Robineau. 2014).
Practically speaking this would mean: No cardio before strength and AM+PM cardio + strength sessions only as an exception to the rule. That's a sound recommendation, but if you look at the actual data, the strength gains on the bench, half-squats and the bench row do not necessarily warrant this advice (see Figure 1). The same goes for the improvements in counter-movement jumps. Are the detrimental effects on MVC gains, really relevant enough to warrant the previously cited recommendation if this is the only way you can do both, cardio and weights? I am not sure.
Furthermore, it remains to be elucidated, whether the existing detrimental effects would occur in trainees who have adapted to this routine over years of practice... personally, I have my doubts. Likewise questionable is, whether the use of protein and/or carbohydrate supplementation in-between the sessions would have changed the study outcome. And last but not least: For those of you who have decided to kick 2015 off with a weight loss regimen, the potential decrease in strength gains are irrelevant | Comment on Facebook!
  • Park, Sang-Kab, et al. "The effect of combined aerobic and resistance exercise training on abdominal fat in obese middle-aged women." Journal of physiological anthropology and applied human science 22.3 (2003): 129-135.
  • Robineau, Julien; Babault, Nicolas; Piscione, Julien; Lacome, Mathieu; Bigard, André-Xavier. "The specific training effects of concurrent aerobic and strength exercises depends on recovery duration." Journal of Strength & Conditioning Research: Post Acceptance: December 24, 2014.
  • Sillanpää, Elina, et al. "Body composition, fitness, and metabolic health during strength and endurance training and their combination in middle-aged and older women." European journal of applied physiology 106.2 (2009): 285-296.