sleep cycle vs sleeping cycle

Some examples from the web:

• And that's really messing up her sleep cycle.
• My sleep cycle is being disturbed!
• The sleep cycle of an infant is only 50 minutes.
• Did Julie adjust your sleep cycle? No.
• I mean, staying up late messes with my sleep cycle.
• The human body can chronically restrict its own sleep cycle without any noticeable effects.
• Melatonin is involved in co-ordinating the body's sleep cycle by acting on cells in specific areas of the brain.
• There is a Smart Alarm which quietly wakes you at the best time in your sleep cycle. It has a battery life of 7 days.
• At certain stages in the sleep process your body will release testosterone, if you are unable to get to that stage in your sleep cycle you will not get the optimal amounts of testosterone being released.
• The use of the night pills eliminates the issue of having too much energy at night, and a full sleep cycle is the key to losing weight! With Phen24 day and night, pounds reduction is a guarantee.
• The human body can chronically restrict its own sleep cycle without any noticeable effects.
• Forgive me if I'm not sympathetic to the fluctuations of your sleep cycle, Mr. Lowe.
• Jessa Gamble: Our natural sleep cycle
• Well, it's very dangerous... to play around with a teenager's sleep cycle.
• Most of us only experience rem sleep once or twice per sleep cycle.
• The human sleep cycle was originally based on the sun.
• Changes in sleep cycle (i.e, night waking, sleeping during the day)
• The product, already market leader in Saudi Arabia and other Middle Eastern countries, will be positioned as a natural restorer of the sleep cycle.
• I mean, staying up late messes with my sleep cycle.
• Dietary supplement of magnesium and vitamin B6 with herbal extracts standardized, useful in rebalancing the normal physiology of the sleep cycle. To facilitate a sleep peaceful and refreshing without causing sensation numbness upon awakening.

Some examples from the web:

• It blocked the sleeping cycle.
• The pineal gland is a tiny organ in the brain that produces the hormone melatonin, a substance that helps control our sleeping and waking cycle.
• Lunar cycles affect sleeping patterns.
• Lunar cycles affect sleeping patterns.
• When sleeping, your body typically goes through several sleep cycles each night.
• Changes in sleep cycle (i.e, night waking, sleeping during the day)
• Most people find that very soothing, and, interestingly, 12 cycles per minute is roughly the frequency of the breathing of a sleeping human.
• SCN appears to be the neural substrate for day-night cycles in body temperature, plasma concentration of many hormones, motor activity, renal secretion, sleeping and waking, and many other physiological parameters.
• After the hair growth period, your hair enters the involutional period, and then sleeping period. At the end of a growth cycle, the hair shaft thins leaving hair without volume.
• And you might say, "Surely, Rueben, if you took even just the slightest step back, the cycles of hunger and eating, waking and sleeping, laughing and crying would emerge as pattern."