Johanna Lanner has answered Unlikely

There is no direct yes, or no answer and importantly it depends on the context and what type of performance that is considered. Nevertheless, when trying to summaries recent studies it appears as, if performance would be considered improved by reducing the symptoms of exercise-induced delayed onset muscle soreness (DOMS, i.e., pain and stiffness experienced in muscles several hours to days (usually 24-72 hours) after unaccustomed or strenuous exercise), then there are reports supporting that post-exercise ice baths have an acute alleviating effect. The physiological explanation is likely linked to that cooling i) reduces nerve impulse transmission and thus reduces the level of pain perception and ii) induces constriction of blood vessels in peripheral tissue (e.g., muscle) which results in reduced fluid diffusion that may assist in reducing exercise-induced acute inflammation and hence reduce pain, swelling and the loss of force associated with inflammation.  On the other hand, if...

Hakan Westerblad has answered Unlikely

Scientific studies show varying outcomes regarding the effect of post-exercise ice baths on the subsequent performance, with results ranging from minor positive effects, via no effects, to negative effects. On the positive side, there seems to be a trend for ice baths to limit muscle soreness after exercise. On the negative side, results indicate that ice baths can limit resistance training-induced strength gains. Clearly, cooling of muscles will slow the recovery of exercise-induced energy metabolic changes (e.g. resynthesis of muscle glycogen), since enzymatic reactions always become slower when the temperature is decreased. Finally, it should be noted that subtle effects can have a large impact in an elite sports context (e.g. less than 0.1 s difference in a 100 m sprint) and such minor changes are difficult, or even impossible, to detect in scientific studies. 

Tina Sundelin has answered Unlikely

The answer to this question depends on what is meant by “meaning”. If the question pertains to the potential meaning of the contents of a recurring dream, the answer is “unlikely". However, recurring dreams occur more often after stressful events, for certain people, and for example in cases of PTSD. So in terms of whether having recurring dreams to begin with might mean something, the answer is that it might indicate that you’ve recently been stressed, are a bit dissociated, or are suffering from PTSD. (Note: this does not mean that recurring dreams equals PTSD. Recurring dreams are very common.)

John Axelsson has answered Near Certain

The purpose of the circadian system is to regulate a number of processes so they are in concordance with the changes of day and night. The master clock (SCN in hypothalamus) has a near 24 hour intrinsic rhythm and is very sensitive to light around dusk and dawn, so to fine tune the circadian system; which allows the system to be dynamic and adapt to the seasonal changes in duration of day and night. Since light is the primary entrainer or 'zeitgeber' of the system, modern technology has a huge impact on our circadian rhythm. Exposure to electric light at times other than during daytime has the potential to strongly affect the rhythm - fooling the rhythm that it is daytime. Recent studies have shown that as little as 25-30 lux in the evening blocks 50% of melatonin in the average person, and people who are more sensitive to light in the evening are more likely to have a late circadian rhythm. Taking people camping, away from their light polluted modern lives, has drastic effects on...

John Axelsson has answered Near Certain

There is today strong support for insufficient sleep (either disturbed or short) and shiftwork to increase the risk for developing type-2 diabetes. For meta-analyses and systematic reviews see:https://www.ncbi.nlm.nih.gov/pubmed/?term=25290038https://www.ncbi.nlm.nih.gov/pubmed/?term=26687279https://www.ncbi.nlm.nih.gov/pubmed/?term=25030030https://www.ncbi.nlm.nih.gov/pubmed/?term=19910503Summarized and discussed herehttps://www.ncbi.nlm.nih.gov/pubmed/27803010

John Axelsson has answered Near Certain

Melatonin is a chronobiotic that can be used to alter a persons circadian rhythm, and hence speed up (or disturb) the adaptation of a persons rhythms to a new time zone. While exposure to light and melatonin give information of daylight and night, it is likely that also cortisol and feed timing can be used to alleviate jetlag. The timing is, however, crucial for whether these aspects will help reduce jetlag or make it worse.

John Axelsson has answered Likely

Short or disturbed sleep results in indivuidals being more sleepy the next day and that they sleep more and deeper (more slow wave sleep) when allowed to sleep the next time. Thus, sleep debt exist. How the brain/body keeps track of the extra need for sleep is not yet well understood.

John Axelsson has answered Near Certain

The brain can definitely catch up on lost sleep. We sleep more efficiently (deeper and more slow wave sleep) when we have a sleep debt. Performance in subjects who have been exposed to long periods of sleep restriction recover within a few days once allowed to recover. The fact that performance recovers despite that we do not get all the hours of sleep back that we have lost, support that sleep is a highly dynamic process that becomes more efficient when need be. This means that at least the brain is good at catching up from lost sleep.That said, sleeping too little may still come at a biological cost. During periods with less sleep, the brain becomes less plastic and we are not likely to retrieve all the memories we never formed. It is also possible that there are other biological costs of sleeping too little repeatedly over time. For example, shift workers are repeatedly exposed to short sleep, and they have an increased risk for developing metabolic disorders such as type-2...

John Axelsson has answered Unlikely

While epidemiological show a U-shaped curve betgween sleep duration and adverse health outcomes, it is unlikely that sleeping longer, per se, is a risk factor. First, the fact that many phenomena, such as sleep need and sleep duration, are normally distributed may explain that being further away from the normal can explain part of this vulnerability. Being in the extremes of a normal distribution is often a risk factors. This means that those who have a larger sleep need, or being more vulnerable to sleep disturbances are more likely to suffer when sleep is disrupted or shorter than their need due to factors such as eaerly starting times at work.Second, a long self-rated sleep duration can be driven by a number of diseases or disorders, particularly those related to inflammation, fatigue or if the disorder disturbs the sleep (e.g. pain) so people have to spend longer time in bed to get the same amount of sleep. A note is that people are much better at judging their bed times than...

Håkan Thonberg has answered Near Certain

It is certain that some forms of Alzheimer disease (AD) are genetic in the sense that they are caused by variations in the genome, so called mutations. Usually such forms of AD, have an onset Before the age of 65. Also, these forms of AD aggregates in families with a pattern that suggests it to be inherited in a dominant autosomal way. Other forms of AD may occur later in life and appear more sporadic among individuals in a family, or in single individuals. Such forms are less genetic, and the influence of inheritance are regarded to cause elevated risk for the disease, as opposite to be causative. So, the answer is yes, but the degree of genetic influence varies from being very small, or even absent, to being 100%.