Biological Rhythms Related to Hypertrophy and Reduced Adiposity
Being in tune with your biological and circadian rhythms is a w
idely overlooked advantage in the quest for the idea physique. More importantly when concerned with increased muscle mass and reduction of fat is the hormonal rhythms experienced daily. Hormonal and physiological rhythms can affect performance and thus goals of hypertrophy. How can that be so?
First it will be important to define a small amount of terminology in order to effectively describe the effects of hormones and the fluctuations that they under go during the day. A circadian rhythm is a cycle describing a whole day in which things occur once. An ultradian rhythm is one that occurs within a circadian rhythm and can happen more than once in a day but operates on a cycle within a day. An acrophase is a period in which hormonal concentrations are at a peak, as opposed to a nadir, which is when the concentrations of a particular reach their lowest point. These terms will be important to remember in the proceeding paragraphs in order to better understand hormonal fluctuations and how they can influence your goals. In relating circadian rhythms to physical performance ut can be helpful in developing an argument for optimizing hypertrophic results of a resistance training program as well as goals of reductions in adiposity for physique goals. By coordinating physical activity with hormonal circadian rhythms one can attempt to achieve optimal synchronization for desired results.
We can relate hypertrophic goals to the optimization of physical performance because hypertrophic training programs are performance concentrated in nature. That is training to failure, or training within rep ranges of 10-12 is going to need a great amount of physical performance. While there are set circadian rhythms for hormone secretions, exercise can affect hormone secretion as can the ultradian hormone secretions can affect physical performance; therefore, the entire point is to synchronize them both for optimal results. For the purpose of this article we will assume your goal will be to maximize muscular gains and reduce fat percentages as much as possible. Oxygen consumption, CO2 production, flexibility, peak knee extension torque and hand and leg strength reach a lowest point at 6:00am and peak at 6:00pm based on some studies. These changes also mirror coincide with and mirror changes in core body temperature. This relationship may be coincidental to temperature changes, however, it is most likely that the temperature changes are due to changes in circadian rhythms and metabolic processes and therefore, hormones.
While mostly we hear about testosterone as being a major component in building muscle, there are a wide variety of additional hormones that are important to consider. We actually want to focus on the combination of testosterone and cortisol when concentrating on circadian rhythms. Testosterone is an anabolic hormone which means, it is conducive to growth and build up of tissues, whereas cortisol is a catabolic hormone, meaning it is conducive to the breakdown of tissues. As you probably already know, or can nor infer, cortisol is your enemy when trying to build muscle. You also probably know that exercise induces increases in testosterone, but what you might not have known, is 
that these exercise induced increases in testosterone are optimized when cortisol concentrations are decreasing. Circadian cortisol rhythm is highest in the morning and declines throughout the day. Those two things being said, resistance training (hypertrophic in nature) performed in the late afternoon would be best in order to optimize increased testosterone concentrations and avoid cortisol interference.
For the portion of this article pertaining to reduction in fat gains, or fat loss (not weight loss), we want to look at growth hormone. Yes, growth hormone is a major component in leanness. As I discussed in my previous article about carbohydrate timing, growth hormone (GH) is more influential on fat loss that it is muscular gains. It does have a muscular recovery component but that is more related to IGF-1. Anyways, for the purpose of this article about circadian rhythms, GH is going to be dictating factor in fat loss. As we also discussed in the carbohydrate-timing article, everyone experiences a GH release peak during sleep. Exercise can also stimulate deep delta-wave sleep in which GH is released. However, exercise can also induce ultradian GH pulses that can further increase frequency and amplitude of its release. The amplitude of these GH pulses released by exercise are dependent on the natural ultradian releases of GH that are occurring in the body day today without exercise. Let me outline this a little better for you by presenting a study to you that observed this directly. First of all it will be important to know that while there is the GH acrophase that occurs during sleep there are smaller ultradian GH pulses throughout the day that occur about every 3-4 hours or (240 min). Studies observed that when exercise was performed 3 times per day at intervals lasting at least 4 hours apart, the exercise induced GH pulses were similar in amplitude. However, when sessions were performed back to back or much closer together in time, the GH pulses experienced were about one half as high. Thus, indicating that if exercise was performed between the GH pulses during the day one can effectively increase overall GH release by 150%-160%!
Core body temperature, which we briefly disc
ussed at the beginning of the article, is also relevant here with GH. Studies have shown that the release of GH is prevented by a reduction in core body temperature. We can then infer that exercise or workouts lasting longer than one hour producing a greater elevation in core body temperature will elicit greater GH responses than shorter or possibly even less intense workouts. Thus, the timing factor or circadian element of this would be the length of the actual workout and should be factored into the GH refractory periods as well discussed above; that is to be fitted within a 4 hour window.
While exercise can influence circadian rhythms, studies that were conducted on overcoming the circadian influx that jet-lag is, have proven that nutrients can also “reset” hormonal phase shifts. These nutrients include but are not limited to the following: amino acids, thiamine, ethanol, retinoic acid, caffeine and glucose. For example, protein rich meals increase wakefulness whereas carbohydrate rich meals can indirectly result in increased sleepiness. While these are a little bit more far fetched in terms of physique related goals, it is important to consider if you are traveling a lot; but, also important to consider when consuming a meal prior to a workout. It would be important to consume a meal with a protein-carbohydrate combination as opposed to only carbs, or only proteins. This is also important because it is evident that combining amino acids and carbohydrates after exercise exaggerates the insulin response after resistance training which means that ultradian meal associated hormonal responses have important impact on protein synthesis in the muscle. This response can also be further exaggerated if exercise is performed fasted versus being performed after a meal. It will be important to consider, however, all of the components at hand. If physical performance is your priority and ultimate increased hypertrophy, and you know that lifting before having a meal is not conducive to your optimal performance it will be important for you to chose wisely. You can still achieve your goals even if are not able to exercise in the fasted state. It just means some hormonal responses are amplified when in the fasted state, but may not always be the perfect thing to do for you, it will just be important that you weigh all of the factors and options and make the best decision that fits YOUR training program and YOUR goals!
While all of this information may have been slightly over your head, definitely try to take time to consider it, or just know that hormones have a huge influence on everything you do. While I also realize everyone is not at liberty to train when they want, and most have to fit it in around other aspects of their life, it is still important to be aware of what is going on inside your body. That way you can make the changes you need to make or take action in whatever direction that is best for your body, and more specifically your own personal goals.
Sources and Photo Credits
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http://technorati.com/lifestyle/article/increasing-height-with-human-growth-hormone/
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