DID YOU KNOW ?
Most athletes, who engage in regular weight training at higher levels work hard in the gym, focus on the best possible training programs and strategies, pay attention to proper nutrition, and are always on the look- out for supplements that may be useful to enhance their training endeavors, their muscle strength and muscle growth. Unfortunately, many of these weight-training enthusiasts fail to realize, how vitally important sleep is for protein synthesis, muscle repair and growth, and even for body-fat-loss. Sleep is one of the most underrated aspects of any training regimen; virtually all critical restorative functions in the body occur mostly or only during sleep. Getting not enough sleep, and especially not enough quality sleep, impacts muscle gains, physical health and the immune system more than many can imagine.
Sleep is a quite complex process; through the course of the night, we tend to go through 5 cycles of sleep on average, each of which normally takes 90 minutes to complete. Each such sleep cycle consists of four distinct phases, with the first three phases being non-REM ( non-rapid eye movement) stages, followed by a so-called REM ( rapid-eye movement) stage.
Every single sleep cycle fluctuates between the three non-REM stages and the REM stage every 90 minutes, although these stages do not always proceed linearly in their right order; also, how much time is spent in each individual sleep stage varies throughout the night.
Per eight hours of sleep and across all sleep cycles, an adult on average collectively spends approximately 2% – 5 % of sleep time in the non- REM-1 stage, 45% – 60% of total sleep time in the non-REM-2 stage, 13% -25%, or 1-2 hours, in the non-REM-3 deep sleep stage, and 20% – 25% in the REM stage.
The non-REM-1 stage lasts only about 1-7 minutes and defines the transition phase of falling asleep.
The non-REM-2 stage denotes a phase of relatively light sleep, accompanied by a drop in brain activity, a decline of body-temperature, relaxation of muscles and a slowed, more regular breathing and heart rate.
The non-REM-3 stage is deep sleep, also referred to as short wave sleep (SWS) or delta sleep, due to the delta brain waves observed during this phase; here, breathing, heartbeat, body temperature, and brain waves reach their lowest levels. During non-REM-3 deep sleep, most of the physical restoration, repair and growth occurs; it is the healing stage. Here, the blood supply to the muscles increases and delivers extra amounts of oxygen and nutrients to the cells, which facilitates repairing organs, bones, and muscle tissue, clearing waste-products, and restoring cellular energy; blood glucose gets stored in the muscle as muscle glycogen. Muscles profoundly relax, which helps with relieving tension and certain chronic pain symptoms. Anabolic hormones are released, especially HGH and IGF-1 (Insulin-like growth factor 1), along with testosterone, all well known for their supreme importance in the muscle building process.
The fourth sleep stage, REM sleep, is characterized by increased respiration and significant brain activity with rapid eye movements and vivid dreams. This stage is critical for mental restoration, memory consolidation and brain clean-up. REM sleep helps to refresh the brain, to better remember and retain vital information, to balance emotions, and to assist with mental alertness. High mental alertness brings about high levels of motivation, which is vital for any bodybuilder’s optimum performance during training. Apart from restoring brain function, REM sleep is also thought to be the time, when free testosterone levels reach their peak, and then stay consistent until awakening.
As already suggested above, the time periods spent in the various sleep stages change as the night proceeds. While non-REM-2 sleep may only last anywhere from 10 to 25 minutes during the first sleep cycle, non- REM 2 sleep – relatively light sleep with fewer recuperative qualities – , grows longer in later sleep cycles as the night advances. On the other hand, the most restorative non-REM-3 deep sleep stages are longer in earlier sleep cycles and become shorter in later sleep cycles, collectively amounting to a total of 1-2 hours per night. The first stage of REM sleep does not occur before you have slept for almost 90 minutes and may just last only ten minutes or so, but each further REM stage becomes longer and can eventually last up to an hour as sleep progresses. In short, as the night advances, the non-REM sleep episodes within the 90 minute sleep cycles get shorter, and the REM sleep episodes get longer.
As non-REM-3 deep sleep phases and the REM stages are the most restorative sleep episodes, and as their duration changes with each new sleep cycle during the course of the night, your best bet to get an adequate amount of sleep in both these most crucial phases is to allow yourself enough time to sleep.
For optimum muscle growth it is vitally important to get 7-9 hours of sleep per night; in fact, getting less than adequate sleep, muscle mass even decreases. The less sleep we get, the less anabolic hormones are released. If you just sleep half of the recommended time, only half of the anabolic hormones are released, and it should not come as a surprise that this will negatively affect your muscles’ recuperation, the replenishment of muscle glycogen, your physical, mental and emotional health and well-being.
Most of the HGH that the body secretes is released during non-REM-3 deep sleep, with the biggest spike occurring during the very first non- REM-3 stage about 70 to 120 minutes after having fallen asleep. HGH release also occurs 4-5 more times during later deep sleep stages. If you go to bed long past midnight, growth hormone and IGF-1 release will still peak in the initial non-REM-3 stages, but as these occur during the second half of the night they won’t reach the levels they normally would have, if you had gone to bed earlier and had gotten a full night’s sleep.