A body hack is a usable technique that can make an improvement to improve a person’s life, health or mental state. These techniques are generally learned through real-life experience and are not necessarily medically recognized. Body hacks may work for some people and not for others and the only way to find out is to give them a try. Here are 24 body hacks we probably would be willing to try and one that we definitely wouldn’t.

Reset Your Body Clock

Shift workers and travelers may be able to fast and successfully manipulate their body clocks. Research suggests the Circadian rhythm (body clock) is primarily controlled by light, but the suprachiasmatic nucleus (SCN) has its own power and influence over the body clock, which allows this body hack to work.

The SCN may be controlled through eating habits. It transfers messages to the dorsomedial nucleus of the hypothalamus (DMH), which makes decisions about when a person is awake and when they should be sleeping.

Dr. Clifford Saper, MD, MS, PhD, who is Chairman of the Department of Neurology at Beth Israel Deaconess Medical Center, and the James Jackson Putnam Professor of Neurology and Neuroscience at Harvard Medical School predicts that humans can reset their body clocks by fasting and eating at different than normal times.

Saper’s research found that when animals were deprived of food, their body clocks adjusted to a new pattern so they could be awake when food became available. By fasting for 16 hours prior to a a trip and eating if they were in the destination’s time zone, travelers may avoid jetlag. Shift workers may also benefit from reseting their body clocks in this manner as their shifts change.

Sleep Less

Developing a polyphasic sleep schedule means sleep is distributed in regularly scheduled blocks around the clock, with the sum of all periods of sleep being less than a regular night’s sleep. Some popular polyphasic sleep schedules include the “Everyman,” which is one three hour block of sleep and three 20-minute naps per 24 hours, the “Uberman,” which is six 20 minute naps per 24 hours and the “Dymaxion,” which is four thirty minute naps per 24 hours. People who need more waking hours may find the polyphasic sleep schedule works for them.

Become an Early Riser

If you would like to start getting up earlier in the morning, it’s best to start off waking up a few minutes earlier for a few days, allowing yourself to get used to the change before changing to an even earlier time. Gradually wake up earlier every few days until you are waking up at the target time. Going to bed earlier, placing the alarm clock far from the bed and resolving not to go back to bed after getting up can help you get a good start as a new early riser.

Get Better Sleep

As a neuroscience major at Princeton, Tim Feriss researched sleep deprivation and has experimented with sleep optimization for increased performance for the last ten years. Feriss recommends consuming 150-250 calories of low-glycemic foods, like yogurt or an apple, before bedtime. This bedtime snack can combat morning fatigue and headaches from low blood sugar through the night. Adding 1-2 tablespoons of flaxseed oil to the bedtime snack can also help decrease fatigue and increase cell repair

Feriss also tested the effects of a 10-minute ice bath an hour before bedtime in combination with a low dose of melatonin. He says the effect is like being hit with an elephant tranquilizer and may not be pleasant.

His research also found a set eating schedule can help regulate melatonin, ghrelin, leptin, and other hormones that affect sleep cycles.

Solve Problems in Your Sleep

Researchers say that you have the ability to problem-solve in your sleep because most memory consolidation occurs while your brain is in a resting state. Studies have shown that people who review material right before bedtime have a better chance of remembering the material and solving problems they viewed. If you are studying for a test or preparing a presentation, your best bet is to do it right before bed so that the material is more likely to be stored as long-term memory.

Stop the Tears

Crying in public can be inconvenient and very embarrassing, but there are things you can do to stop the flow of tears. Holding your eyes wide open without blinking can often stop tears from starting. If you have already started to cry, look upward with your eyes without tilting your head back to stop the tears. Relaxing your jaw may also help hold back the tears, but if that doesn’t work you might try gently biting your tongue to re-direct your attention to a slight physical pain until the emotional pain subsides.

Stifle Inappropriate Laughter

Inappropriate laughter can be embarrassing and contagious. If you are in a situation in which a bout of laughter would be frowned upon you can prepare by thinking of something sad to kill the urge to laugh. If you still find yourself wanting to laugh inappropriately, you can distract yourself with a physical sensation by pinching yourself, biting your tongue or holding your breath. If you still burst out in laughter, despite doing everything possible to stop it, you can attempt to disguise your laughter as a coughing fit and step into a restroom to compose yourself. Exhale as much air as you can from your lungs to stop laughing, count backwards, put on a straight face and return to the party or gathering.

How to Cure Hiccups

There are several methods people use to cure themselves of hiccups. None are medically proven and success may vary greatly from one person to another. Some people are able to stop hiccups by holding their breath for as long as possible before exhaling slowly. If that doesn’t work, sometimes the drinking method is successful. For the drinking method, a person plugs their ears with their fingers while plugging their nose with other fingers. With the remaining fingers, the person picks up a 12 ounce glass of water (using only their lips and jaw muscles) and drinks as much as they can, as fast as they can. Other possible remedies include breathing into a paper bag, suffering a fright, immersing your face in ice-water for 30 seconds or swallowing a teaspoon of dry, white granulated sugar.

Be a Human Lie Detector

You can be a human lie detector just by picking up on somewhat subtle details about a person’s behavior. Crossed arms are a signal indicating the need for self-preservation or a block against the issue being discussed. When a person is lying, the speed and pitch of their voice will often change and they may stutter, stammer and/or avoid eye contact. Nervous twitches or less obvious shifts in body-position may also be a clue that a person is lying.

Prevent a Hangover

There are often consequences after a night of alcoholic indulgence. Luckily, a hangover is one of those consequences you can take measures to prevent. When you consume alcohol, the ethanol increases prostaglandin formation, depletes B vitamins and magnesium, and depletes usable glucose for the brain. The basic result: You may be in a shitty mood and feel fatigued and groggy.

Taking N-Acetylcysteine before a night of drinking may help prevent some hangover symptoms. This drug is generally used for treatment of paracetamol overdose, but can also scavenge the toxins that ethanol produces in the body. It is not recommended that you take N-Acetylcysteine after a night of drinking.

Taking B-complex and folic acid after consuming alcohol can help prevent a hangover by replacing what the ethanol depleted in your body.

Staying hydrated can also go a long way towards preventing a hangover. If you drink Gatorade or Pedialite, you also replace magnesium and electrolytes and give your brain some needed glucose. The same trick has been discovered by thousands of people who noticed that a Vodka-Redbull somehow manages to both intoxicate them, and stave off a hangover as well.

Stop or Force a Sneeze

Many times you can’t stop a sneeze, nor should you try if you have already started to sneeze. A sneeze pushes air out of the mouth and nose at speeds of up to 100 mph. However, if you feel a sneeze coming on and want to stop it before it starts, pressing your tongue firmly behind your teeth may help. You can also try tickling the roof of your mouth with your tongue or pinching the tip of your nose to stop the sneeze sensation. If you feel a sneeze coming on and want to get it over with, looking onto a bright light can induce sneezing.

Ease a Toothache

If you have a toothache and can’t see a dentist right away, you can ease the pain without even opening your mouth. By rubbing an ice cube on the V-shaped webbed area between your thumb and index finger on the back of your hand you can reduce the toothache pain by as much as 50 percent. At the base of the webbed V there are nerve pathways that stimulate an area of the brain to block pain signals from the face and hands.

Improve Your Memory with the Link Method

Memory can be improved by developing a recall technique called the Link Method. This method helps you remember and recall information by associating it with a word or story that you can visualize in your mind. When trying to memorize a list of items or facts, a combination of word association and a story form is effective. By associating the items you are memorizing with familiar things and linking them together a memorable story is formed. Storing the information in your brain this way allows for easy recall later.

Improve Your Vision

For a temporary vision improvement, you can curl your hand into a fist and look through it as you would a telescope. This trick allows only a narrow beam of light to reach the retina and increases the depth of field and focus.

Dilate or Shrink Your Pupils at Will

The study of pupilometrics, or the relationship between human emotions and the size of the pupils, has revealed that the size of a person’s pupils can be controlled. Some people are able to dilate their pupils by tensing their stomach muscles, picturing something that gives them an adrenaline rush or focusing on objects that nearby. To decrease pupil size, increase the amount of light, relax the stomach muscles while keeping the pelvis and hips aligned with the shoulders and focus on an object at a greater distance.

Stop Brain Freeze

Sometimes eating ice cream or drinking a frozen drink can cause the very unpleasant “brain freeze” effect. To combat brain freeze, press your tongue flat against the roof of your mouth. The more pressure you are able to apply with your tongue, the faster relief will come.

Improve Your Hearing

If you are having trouble hearing what someone is saying, try turning your right ear to the conversation. Your right ear is better at picking up speech patterns.

If you’re stuck chatting up a mumbler at a cocktail party, lean in with your right ear. researchers at the UCLA David Geffen School of Medicine say your right ear is better than your left at following the rapid rhythms of speech, according to researchers at the UCLA David Geffen School of Medicine. For music, the opposite is left ear.

Clear Your Sinuses

If you have sinus congestion and steam just isn’t doing the trick, there’s another body hack you can try to relieve the pressure. Thrust your tongue against the roof of your mouth, then press between your eyebrows. Repeating these two things rocks your vomer bone back and forth and loosens up the congestion, allowing your sinuses to drain.

Avoid Side Stitches

During or after a run, some people will occasionally get a “side stitch.” This pain in the side is generally a product of exhaling as the right foot hits the ground, thus putting downward pressure on the liver and causing it to pull on the diaphragm. To avoid side stitches, exhale as your left foot hits the ground during runs.

Prevent Acid Reflux

If you frequently suffer from acid reflux at night, you may find relief is as simple as sleeping on your left side. If you sleep on your right side, your stomach is higher than your esophagus, which allows gravity to promote acid reflux. By sleeping on your left side, you position your stomach lower than your esophagus and have gravity on your side to keep food and acid in your stomach.

Improve Your Posture

The correct way to improve your posture is not to force yourself to sit up straight. Forcing yourself to have good posture is counterproductive and will fatigue your muscles and cause soreness. To properly correct your posture, work on exercises that strengthen the muscles around your shoulder blades and mid-back and your posture will automatically improve.

Circular Breathing

A technique called circular breathing allows some musicians of wind instruments to produce sound without interruption. When practicing circular breathing, the person breathes in through the nose while exhaling through the mouth. Air is stored in the cheeks so that there is a continuous supply. Saxophonist Kenny G previously held the world record of 45 minutes for continuous play of a wind instrument, however Costa Rican saxophonist Geovanny Escalante now holds the world record of almost 90 minutes.

Hold Your Breath Longer

You can hold your breath underwater for about 10 seconds longer if you hyperventilate before diving down. When you are underwater, usually the buildup of carbon dioxide makes your blood acidic, which triggers your brain to let you know something’s wrong. By taking several short breaths before going underwater, you fool your brain into thinking it has more oxygen and have more time before alarm bells go off.

Boost Your Car Remote with Your Head

If you forget where you parked and your key remote signal is not strong enough to help you find the car, there is a simple trick to amplify the signal and increase your chances of easily finding it. Simply place the remote under your chin, open your mouth and press the button. Your oral cavity will amplify the signal and with any luck, you’ll locate your car immediately.

Stop Your Pulse

This is not recommended. It’s actually a trick, rather than a true body hack, but can still be dangerous. A person can make the pulse on their wrist slow and stop for a short period of time by placing a rolled up pair of socks or a tennis ball in their armpit. By squeezing the arm in to the body, the blood flow is restricted and the pulse in that arm slows and may stop.