Sit-up

The sit-up is an abdominal strength training exercise commonly performed to strengthen the abdominal muscles. It is similar to a crunch (crunches target the rectus abdominus and also work the external and internal obliques), but sit-ups have a fuller range of motion and condition additional muscles. Sit-ups target the hip flexors, rectus abdominus and also work the iliopsoas, tensor fasciae latae, rectus femoris, sartorius, and, to a very small degree, the obliques.

Form

It begins with lying with the back on the floor, typically with the arms across the chest or hands behind the head and the knees bent in an attempt to reduce stress on the back muscles and spine, and then elevating both the upper and lower vertebrae from the floor until everything superior to the buttocks is not touching the ground. Some argue that situps can be dangerous due to high compressive lumbar load and may be replaced with the crunch in exercise programs.

Strength exercises such as sit-ups and push-ups do not cause the spot reduction of fat. Gaining a "six pack" requires both abdominal muscle hypertrophy training and fat loss over the abdomen—which can only be done by losing fat from the body as a whole.

StuffIt

StuffIt is a family of computer software utilities for archiving and compressing files. Originally produced for the Macintosh, versions for Microsoft Windows, Linux (x86), and Sun Solaris were later created. The proprietary compression format used by the StuffIt utilities is also termed StuffIt.

Overview

StuffIt was originally developed in the summer of 1987 by Raymond Lau, who was then a student at Stuyvesant High School in New York City. It combined the fork-combining capabilities of utilities such as MacBinary with newer compression algorithms similar to those used in ZIP. Compared to existing utilities on the Mac, notably PackIt, StuffIt offered "one step" operation and higher compression ratios. By the fall of 1987 StuffIt had largely replaced PackIt in the Mac world, with many software sites even going so far as to convert existing PackIt archives to save more space.

StuffIt soon became very popular and Aladdin Systems was formed to market it (the last shareware release by Lau was version 1.5.1). They split the product line in two, offering StuffIt Classic in shareware and StuffIt Deluxe as a commercial package. Deluxe added a variety of additional functions, including additional compression methods and integration into the Mac Finder to allow files to be compressed from a "Magic Menu" without opening StuffIt itself.

Sitting

Sitting is a rest position supported in humans by the buttocks or thighs where the torso is more or less upright. Sitting for much of the day may pose significant health risks, and people who sit regularly for prolonged periods have higher mortality rates than those who do not.

Role and evolution

Although chairs with backrests have only been common in Europe since the 16th century and office workers sitting at work was uncommon even in the early 20th century, the British Chiropractic Association said in 2006 that 32% of the British population spent more than ten hours per day sitting down.

Positions

On the floor

The most common ways of sitting on the floor involve bending the knees. One can also sit with the legs unbent, using something solid as support for the back or leaning on one's arms. Sitting with bent legs can be done with the legs mostly parallel or by crossing them over each other.

A common cross-legged position is with the lower part of both legs folded towards the body, crossing each other at the ankle or calf, with both ankles on the floor, sometimes with the feet tucked under the knees or thighs. The position is known in several European languages as tailor style, from the traditional working posture of tailors; compare tailor's bunion. It is also named after various plains-dwelling nomads: in American English Indian style, in many European languages "Turkish style", and in Japanese agura (胡座, The sitting style of non-Han ethnics (particularly Turks, Mongols and other Central Asians.)). In yoga it is known as sukhasana.

Sit (island)

Sit is an uninhabited Croatian island in the Adriatic Sea located between Žut and Pašman. Its area is 1.77 km² (0.68 sq mi).

The coastline is not significantly indented, except for the bay Pahaljica (Čitapićev port) to the north of the island. Its middle width of 500 m consists of only one mountain ridge, where the highest elevation Veli vrh (84 m) is located east of the island, the central hill Vlasic high is 78, and the northwest end Borovac 60 m

References

External links