Wednesday, June 24, 2015

It's the Same (!) Time of the Day That Matters, If You Want to Excel - No Matter if You're in a Training or Detraining Phase

If you have a competition in the AM and usually train in the PM it may make sense to change your training schedule in the weeks leading up to the event.
Alright, in previous SuppVersity training I've already discussed that it's pointless to try and train at maximal volumes and intensities on 365 days a year and 90+ years a life. In addition it's often simply mandatory that you take some time completely off the gym. That may be hard for some, but we know from previous studies that this does not mean that you will have to start anew when you're back on the grind... well, at least if this "being back on the grind" doesn't happen after months of doing nothing.

In a very recent study, scientists from the Sfax University, the Hellenic Army Academy, and other institutes and universities tried to determine, once again, how long it will take until the performance decrements become so relevant that they've eaten up all your gains (Chtourou. 2015).
You can learn more about sleep and the circadian rhythm at the SuppVersity

Sunlight, Bluelight, Backlight and Your Clock

Sunlight a La Carte: "Hack" Your Rhythm
Breaking the Fast to Synchronize the Clock

Fasting (Re-)Sets the Peripheral Clock

Vitamin A & Caffeine Set the Clock

Pre-Workout Supps Could Ruin Your Sleep
Now, this alone wouldn't be really news-worthy. After all, the study population of 31 subjects is relatively small and there's also plenty of data from previous studies. What makes the study Chtourou and colleagues did interesting is that they also tested whether the performance decrement would differ if you train in the AM or PM.

So, to test not just if you can keep your gains during a detraining period of 2-5 weeks, but also to evaluate whether the time at which you were training and are now retested would matter, Chtourou et al. recruited thirty-one healthy male physical education students (age: 23.1±1.9 yrs; height: 176.1±6.3 cm; weight: 74.9±10.9 kg). Initially 2/3s of the subjects participated identical leg training regimens for 14 weeks (knee extensor and flexor muscles of both legs | the rest served as inactive control) - with half of them performing their workouts in the AM, the other half in the PM (one group didn't train and served as control). This leaves us with the following three groups in total:
  • a morning training group (MTG, who trained between 07:00 and 08:00 h, n = 10), 
  • an evening training group (ETG, training 17:00 and 18:00 h, n = 11) or 
  • a control group (CG, did not train, n = 10). 
During the actual training phase (where you want to build muscle and power), here the first 12 weeks, the participants in the MTG and ETG groups performed 10 repetitions to failure per set (10 repetitions with a weight that could only just be lifted ten times) during 3 sets of 4 exercises (Squat, Leg press, Leg extension and Leg curl) with a recovery period of 2 minutes between each set.
This study is also relevant for those doing research: As the results of the study show, it may make a significant difference if you test your subjects at the same time they are used to train (maximal gains) or 8-10 before or after. Eventually, one may even go so far as to say that all older studies, where the "test and train at the same time principle" was not adhered to may have underestimated their own results - slightly, but measurably. Whether that's actually relevant in view of the fact that comparing absolute gains from one study to another is questionable, but you could imagine a retest being done in the AM where all the training took part in the PM diminishing the performance increment to an extent that it doesn't reach statistical significance.
During the last two weeks, the training intensity was increased to 8-RM (8 repetitions with a weight that could only just be lifted ten times) and the recovery period between each set of exercises was increased to 3 minutes. Throughout the study, the RM (intensity at which you lift to failure) was kept in the desired training zone, by adjusting the weights according to performance improvements. To make sure this worked out, all resistance training sessions during the study were supervised by one ofthe investigators. This person also made sure that the obligatory 10 min of warm-up/dynamic stretching, the 10 min cool-down and the warm-up sets with 8-10 repetitions using a light weight
for all exercises were actually performed.
Figure 1: Maximal voluntary contraction (MVC) recorded at 07:00 h and 17:00 h in the morning training group (MTG), the evening training group (ETG) and the control group (CG) before (pre-training) and after (post-training) training period, 3 and 5 weeks detraining after the end of the training period. *, sign. difference between 07:00 h and 17:00 h. A, B and C: significant differences in comparison with pretraining, post-training and + 3 weeks detraining, respectively (Chtouru. 2015).
When the last set had been pumped out, the MTG and ETG group returned to their irregular and light (non-resistance training) physical activities for the remaining 4-6 week detraining week during which their performance was tested at the end of weeks 4 and 6 - once in the AM and once in the PM.
Now what is really interesting to see is that both training regimen appeared to have a "specialization" effect. While the MTG group which trained in the morning showed the most significant performance gains when they were tested at 7:00 am, the exact opposite was the case for the ETG group who had been training in the evening all along.

That's not relevant? Well, if take a closer look at the data, you will see that in both training groups, most SJ and MVC performances had returned to pretraining levels during the "non-accomodated" test. Significant performance gains over the pre-values were detected only in the 7:00 am test in the morning group and the 17:00 pm test in the evening group and thus at exactly the same time, the subjects were used to train.
SuppVersity Classic: "Is Resistance Training in the PM More Anabolic Than in the AM? Time of the Workout Doesn't Influence Acute Hormonal Response or Circadian Pattern of Testosterone Production" | read the whole SV Classic article
How does this matter? Well, first of all it confirms that we are creatures of habbit; and that's by no means a merely psychological thing. If we have en-trained a certain rhythm, out biological clock will set all our body functions in ways that allow us to function optimally when the body expects it to be necessary. On the other hand, the study at hand highlights the unfortunate truth that you can easily lose "all" your strength gains within only 5 weeks of doing nothing. Yes, there's a residual increase if you at least train at your usual training time, but there's no debating that detraining, i.e. doing no sport-specific (in this case resistance) training anymore for several weeks can be a set-back. If you want to take a break. Do it for 2-3 weeks max and consider tapering instead of detraining as an option.

Ah, and yes, although the study doesn't really have the power to make a far-reaching conclusion, it would at least appear as if PM training was more effective. But as a I said, that's just a conjecture and not a promise that you will increase your gains if you start - all of a sudden - training in the PM. Why? Well (a) you would train to an unaccustomed time and (b) even the support from previous studies like Chtourou et al. (2012, 2013 & 2014) is not fully convincing when it comes to chronic resistance training gains vs. acute performance benefits. What appears to be a reliable though is that people who usually train in the PM may benefit significantly from a few weeks of training in the AM before a meet or competition at 7:00 or 8:00 AM, i.e. not their usually training time | Comment!
  • Chtourou, Hamdi, et al. "The effect of strength training at the same time of the day on the diurnal fluctuations of muscular anaerobic performances." The Journal of Strength & Conditioning Research 26.1 (2012): 217-225.
  • Chtourou, Hamdi, et al. "The effect of time-of-day and judo match on short-term maximal performances in judokas." Biological Rhythm Research 44.5 (2013): 797-806.
  • Chtourou, Hamdi, et al. "Diurnal variation in long-and short-duration exercise performance and mood states in boys." Sport Sciences for Health 10.3 (2014): 183-187.
  • Chtourou, Hamdi, et al. "Post-resistance training detraining: time-of-day effects on training and testing outcomes." Biological Rhythm Research just-accepted (2015): 1-22.