How to fall asleep:
Both temperature and timing can have serious impacts on your sleep cycle. Light plays such a huge role in telling us when to fall asleep that when we don't have all-day sunlight as a cue, we can feel a little off. Specifically, the brain’s “master clock” (called the suprachiasmatic nucleus (SCN); it sits just above the optic nerves) gets a lot of information and direction from the light we see, which, in turn, causes the SCN to tell the pineal gland to produce more or less melatonin. When it’s darker out, we make more melatonin, which makes us feel drowsier.
What to eat:
The season also brings changes in which foods are available. And, in the winter, Grace McCalmon N.T.P. (and founder of The Real Food Nanny) says we should be on the lookout for root vegetables and squashes. These foods tell our kidneys to produce more vitamin D — extra-important since we're getting less of it from the sun during winter. Other great sources include fatty fish, like tuna and salmon. You can also get vitamin D in smaller amounts from milk, egg yolks, and cheese.
What to wear:
Whether you’re working out in the cold or just walking to the subway, taking a few tips from cold-weather hiking can keep you comfy without adding too much bulk. You should work with three layers: The base layer wicks moisture from your skin, the mid-layer adds insulation, and the shell protects you from rain and snow.