The Physics Involved in Throwing a Discus

The shape of a discus resembles the airfoil of an airplane wing, which gains greater lift as wind speed increases, according to aerodynamic engineers. As a result, you can throw a discus farther against the wind than with it, according to a 2000 report by the University of California Davis. Computer simulations and test flights also show that the gyroscopic spin of a discus, atmospheric conditions and altitude affect discus flight in various ways.
Aircraft gain greater lift in cold air because its slower-moving molecules are closer together than warm air, making it denser. Cold air gives any aerodynamically shaped object, such as a discus, more support to stay aloft. Research at the University of Texas Institute for Geophysics reported in the “American Journal of Physics” that a discus travels about 5 inches farther on a cold winter day at 32 degrees than on a hot summer day at 104 degrees. Air is also denser at sea level than high altitudes. A discus travels 7.5 inches farther in Rome, Italy, 120 feet above sea level, than in Mexico City, 7,300 feet above sea level.
A discus spins as it leaves an athlete’s hand. This gyroscopic, spinning motion stabilizes the discus in flight. The faster it spins, the greater its angular momentum and the more its gyroscopic action resists tilting or changing its spin axis. The cross-section of a discus is wing-like, so spin holds its aerodynamic shape pointed into the wind. This maintains lift and prolongs flight time.
Baseball pitchers and football quarterbacks know their throws will lose speed when they throw into oncoming winds. However, a discus thrower combines the physics of aerodynamic lift and gyroscopic stability with a headwind to gain an advantage. The Texas researchers documented that a discus thrown into a 20-mph headwind can fly up to 25 feet farther than a discus thrown with that wind.
The characteristic spinning windup and delivery of a discus thrower creates great speed at release. While a baseball pitcher has, at most, only a 180-degree arc through which to accelerate the ball before release, the discus thrower has two full spins. In addition, as also practiced by figure skaters, drawing the arms inward while spinning preserves angular momentum by increasing spin velocity. Careful timing increases acceleration just before re-extending for release. The best discus throw combines physical strength with complex physics.

How a Football Feels When Inflated Correctly

In order to play the game of football well, your ball must be inflated correctly. If properly inflated, the football will travel farther and faster in a straighter pattern than a ball that is not fully inflated or that is overly inflated. You can use the gauge on your pump to measure an exact pounds-per-square-inch reading, but you’ll also need to learn the proper feel of an perfectly inflated ball.
When inflating your ball, you can use either a hand pump or an air pump equipped with a gauge that gives readings in pounds per square inch, also called psi. Footballs used in the NFL are inflated to 13 psi, but a proper range can fall between 12.5 and 13.5 psi, according to Wilson Sporting Goods. A football shouldn’t be squeezable, it should be taut and firm, but not hard. If you are using an older football, remember that leather hardens over time, so it may feel harder than a newer football. If your ball looks wobbly in flight, this can be a sign of a deflated ball, so check the psi.

The Best Way to Strengthen Your Arm for Baseball

The ability of a player to throw hard and accurately is a valued asset to any baseball team. Who isn¡¯t impressed by the pitcher who hurls a blazing fastball past hitters or the outfielder who gets the ball to home plate on one bounce? Whether you are in the little or big leagues, you can add velocity to your throws by following a well-designed resistance training program. And by strengthening the muscles in your arms, shoulders and back, you stand a better chance of avoiding the disabled list.
While it is possible to see improvements in as early as a few weeks, you¡¯ll achieve the best results by starting your strengthening program early during the off-season. This allows you more time to build up arm strength. It also allows you to include strenuous training sessions that build muscle and schedule ample recovery time. Once the season starts, your training program should be redesigned to maintain the strength you gained without overtaxing your body for practice and games.
Throwing a baseball is a complex movement involving all the major joints of the arm — shoulder, elbow and wrist. Your strengthening program should include all the muscle groups associated with these joints. Dr. James R. Andrews, one of the world¡¯s leading sports-specific orthopedic surgeons, recommends on the Andrews Sports Medicine & Orthopaedic Center website the Thrower¡¯s Ten Exercise Program. This comprehensive set of resistance exercises is specifically designed for athletes who use an overhead (overhand) throw. Build up your base of strength by gradually increasing the amount of weight you lift over time.
A 2005 survey of major league baseball strength and conditioning coaches found 16 out of 21 used upper body plyometrics training. Plyometrics are a variation of resistance training designed to maximize explosive power output. They combine moderate weights with fast, forceful movements that work multiple muscle groups. Medicine ball throws against the floor or wall are examples of upper body plyometric drills designed to strengthen the muscles involved in the overhead throwing motion.
Weighted baseball drills reinforce interactions between the nervous system and muscles by using your actual throwing motion. For example, throw three sessions per week, using specific pitch counts and a combination of weighted and standard baseballs. Weighted baseball drills put more stress on the joints, so be sure you have established a foundation of muscle strength from general resistance and plyometrics training before advancing into these.
Putting maximum velocity on a baseball engages your entire body, creating a kinetic chain that links your legs, trunk and arms. Thus, part of your training program should include exercises to strengthen your lower body. Avoid endurance-type training, such as extended running, which actually reduces your explosive power. High-intensity, short-duration running drills will help develop the right combination of strength and speed.

Football Facemask History

Before the 1950s, football players rarely wore face masks, and some, such as punters and quarterbacks, were slow to adopt them even as they started to gain acceptance. When players did begin to wear them, they often tweaked them to their personal preferences, further complicating the face mask’s evolution.
In the 1920s, players wore nose guards as their only means of facial protection. Made of leather, they evolved in the 1930s to cover a player’s entire face with holes cut out for the eyes and mouth. They were hot and uncomfortable, and players were understandably reluctant to use them. The helmet manufacturer Riddell created the first modern face mask for Otto Graham, a quarterback with the Cleveland Browns, in 1953. Legend has it that Graham took an elbow to the teeth in the course of play, and he decided enough was enough. His coach taped some plastic to the front of his helmet, and a few weeks later, Riddell produced a helmet with a permanent shield of Lucite across the front.
Graham’s Lucite face mask proved to be impractical because the Lucite shattered on impact, cutting players and spraying Lucite fragments in their eyes. The NFL outlawed the substance for use in football helmets in 1957. Riddell’s next helmet to include any sort of face mask was the BT-5. It involved just a single bar across the front of the helmet, made of rubber and plastic. The BT-5 gave way to a series of improvements over that single bar. Double bars, then triple bars, followed, with some linemen wearing entire cage-like coverings over their faces. Riddell made S-Bar face masks with a special protective eye covering as of 2010, but face masks are still individualized to players’ preferences and can involve different patterns of several bars.
In the 1960s, Otis Taylor of the Kansas City Chiefs reportedly bolted two face masks onto his helmet simultaneously for ultimate protection. Joe Theismann, quarterback for the Washington Redskins, preferred the old-style one-bar face masks so much that when Riddell stopped producing them, he bent the bar backward and downward on the new version so he could still see the playing field without obstruction. Some players, however, bent the bar upward to protect their noses better. In 1974, the Kansas City Chiefs had their face masks painted white to contrast with players’ hands so that officials could plainly see when an opposing player grabbed one.
The NFL ruled for the first time in 1956 that it was illegal for one player to grab another by his face mask — except if that player was carrying the ball. In 1962, the NFL upgraded the rule to include all players. Tinted visors were officially prohibited as face masks in 1987, except if a player requires one for an optical condition. Up until 2008, inadvertently grabbing a player by his face mask brought a five-yard penalty and intentionally grabbing it to stop or bring a player down brought a 15-yard penalty. In 2008, however, the NFL dispensed with the five-yard version.

Cal Hubbard

Cal Hubbard was huge by the standards of the 1920s. When he first appeared on the pro football scene, he was 6’5″, and 250 pounds. Moreover, he could run 100 yards in a speedy 11 seconds. The total effect was awesome.
Hubbard (1900-1977) played college football at Centenary and Geneva, hardly the big time. But, when he turned pro in 1927 at the comparatively ripe age of 26, he went straight for the biggest arena of all — New York.
The Giants were well stocked at tackle, so Hubbard moved over to become the biggest, most fearsome offensive end in the NFL. On defense, he played linebacker.
The addition of big Cal made a good Giant defense great. The New Yorkers posted 10 shutouts in 13 games and allowed only 20 points for the season while winning their first NFL title.
When complacency, age, and dissension dropped the Giants to the middle of the standings the next season, Hubbard asked to be traded.
Hubbard couldn’t have timed it better. Cal was sent to Green Bay just as the Packers were becoming a dynasty. He became the key tackle on a team that won NFL championships for three straight years — 1929, 1930, and 1931.
For all his spectacular defensive play, Hubbard may have been most valuable for his blocking. With his size and speed, he opened holes in the most determined defenses. When the NFL named its first official All-League team in 1931, he was chosen at tackle. In 1932 and 1933, he was named again.
During summers at Green Bay, Cal began umpiring baseball games. In 1936, he began a new career as an American League umpire. He wore the blue for 15 years and then served as supervisor of AL umpires for 15 more.
In 1976, the year before his death, he was named to the Baseball Hall of Fame. He was the first person to be enshrined in both the Baseball and Pro Football Halls of Fame.

I heard someone mention a third team in a football game. What is that? Who are these guys and what do they do?

A football game actually consists of three teams, with the third team being the officiating crew. They also have a uniform, which consists of a shirt with vertical black and white stripes, white pants, and a white or black hat. These men are responsible for enforcing the rules of the game as outlined by the NFL rules committee. An NFL officiating crew consists of six men, and each has distinct responsibilities:
These men must memorize and be ready to call an infraction in a split second. An official signals an infraction by throwing a yellow flag. There are many rules in the NFL Rule Book; here are a few of the ones of which you might be unaware:
For more information about American football, check out How American Football Works.
Here are some interesting links:

Interval Training for Soccer

A soccer game is just like 90 minutes of interval training — running full speed, slowing down when you reach the ball, weaving between defenders, and sudden stops to shoot or change directions, note the former pros at the online site Soccer Training Info. You must train your body to perform according to the demands of a soccer game.
At its simplest, interval training can involve laps around the field, alternating between light jogging and sprints as you reach a corner flag or the midfield line, suggests ExpertFootball.com. If you feel out of breath, slow down on the jogging segments to aid your recovery. Or try shuttle runs — stand on the goal line facing the field. Sprint to the six-yard line and back, and rest for 10 to 15 seconds. Sprint to the 18-yard line and back. Rest and sprint to the midfield line and back, and rest and repeat the 18-yard shuttle and finally the six-yard shuttle, with rests between all. One rep consists of five of these sprints.
Before engaging in interval training, work for six to eight weeks on aerobic exercises, such as running, swimming and cycling. Do this three to four days a week for 30 minutes, recommends the head men’s coach at Skidmore College in Vermont, in the book “The Soccer Coaching Bible.” During the early stages of interval training, have a rest-to-sprinting ratio of 3:1 or 4:1 to protect players from injury. Decrease the rest ratio to 1:1 as the players achieve higher levels of fitness.
Resting time is crucial for successful interval training, notes Soccer Training Info. Resting allows your muscles to recover from the intensity of sprinting. Muscles rely on the conversion of glucose to lactic acid to generate energy during exercise. Your rest period enables the muscles to recover from their strain, which can only be sustained briefly, as you inhale oxygen and metabolize more glucose.
Researchers at the Norwegian University of Science and Technology in Trondheim published findings in 2001 based on 19 male elite junior soccer players. They divided the players into two random groups. One group undertook interval training consisting of four 4-minute runs at 90 percent to 95 percent of maximal heart rate, with a 3-minute rest in between, twice a week for eight weeks. The researchers found increases in the athletes’ maximal oxygen uptake. The players covered 20 percent more ground during a match compared to the control group. The researchers concluded that interval training enhanced work intensity, number of sprints and involvements with the ball during games.
While soccer requires technical and tactical skills, physical resources such as endurance, strength and speed play crucial roles, notes Jan Helgerud and colleagues, who conducted the Norwegian study. Interval training may also prove crucial — Helgerud’s literature review discovered studies finding that the rank of the best four teams in the Hungarian premier soccer division matched their ranking on average maximal oxygen intake. Similar results come from a study of teams in the Norwegian elite division.

Youth Football Defensive End Drills

In youth football, you do not have to worry about complicated passing offenses. The defensive end’s job in youth football is generally to contain the offensive running game and turn the play back to the inside. Any time the ball goes outside of the offensive tackle, the defensive end must be able to get off of the block and make the play.
Whether you use a four-man front or a five-man front, the defensive ends are responsible for containment, which means that no one running the ball can get outside of them. To hone this skill, have the defensive end attack the outside shoulder of an offensive lineman. His hands should go to the outside shoulder and armpit of the tackle to control him. Do not have the defensive end rush upfield, as this leaves too much room inside for the running back to run through. Instead, have the end practice staying on the line of scrimmage with his arms locked out to control the tackle. When he sees the ball carrier, he should throw the tackle to the inside and go make the play.
In youth football, most teams use double teams on the tackle when running a sweep to his side. The tackle and tight end will double the end to get to the outside of the defense. Teach your end how to defeat a double team. He should never try to go around the blockers. Have him line up on the outside shoulder of a tackle, with a tight end outside of them. When both blockers come to him, the end should try to drive a foot between the blockers and turn his hips to get skinny and slide between the linemen. Once they turn their shoulders in toward each other, the end has won. At times in the drill, the end will try to step through and be unable to. If this happens, the end must go to the ground, pulling both linemen down on top of him at the line of scrimmage to create a pile in the hole.
Young ends need only two moves on a pass rush. In a one-on-one pass rush drill, or against stand-up dummies, have the end attack the outside shoulder of the tackle. He should run upfield, leaning into the tackle and dipping his inside shoulder, ripping his inside arm up through the armpit of the tackle while curving toward the quarterback. After he makes this move a few times, the tackle will begin to rush backward to cut him off. The end should rush upfield for four steps, then plant on his outside foot and run inside of the retreating tackle, dipping the outside shoulder and ripping the inside arm of the tackle.

Dan Fouts

If ever there was a player destined to be an NFL quarterback, it had to be Dan Fouts.
From an early age, Fouts, a San Francisco native, seemed to be in the right spot at the right time. His father, Bob Fouts, was the play-by-play radio announcer for the hometown 49ers and, as such, pulled a few strings to get his son a job as the team ball boy.
After Dan led his St. Ignatius Prep football team to a city championship, he went to the University of Oregon, where they ran a pro-type offense. There, he set school records with 5,995 career passing yards and 37 touchdowns.
The San Diego Chargers made Fouts (born 1951) a third-round draft pick in 1973. As a rookie, he was a backup to his “idol,” Johnny Unitas. Fouts replaced the battered veteran in the fourth game of the 1973 season. Dan was never out of the starting lineup again.
Although Fouts’ play improved each of his first three seasons, the team did not. Then in 1976, the Chargers named Bill Walsh offensive coordinator, and Fouts’ career really began to blossom. His good fortune continued when, in 1978, Don Coryell signed on as the team’s new head coach.
Coryell implemented a high-powered, pass-oriented offense, and from then on it was “bombs away. Fouts directed the offensive assault dubbed “Air Coryell.”
With Fouts at the controls, Air Coryell transformed the Chargers from also-rans to AFC Western Division champs in 1979, 1980, and 1981. Named both NFL and AFC Player of the Year in 1979, he led the conference in passing and broke Joe Namath’s record for passing yards gained in a season (4,082).
In 1980, Fouts broke his own yardage record with 4,715 yards, then broke it again in 1981 with 4,802. In 1982, he again earned NFL Most Valuable Player honors.
In 15 seasons, Fouts completed 3,297 passes for 43,040 yards. At the time of his induction into the Pro Football Hall of Fame (1993), he was one of only three quarterbacks to pass for more than 40,000 yards.
To learn more about football greats, see:

2010 in Pictures

On Jan. 12, a 7.0-magnitude earthquake struck Haiti, a nation widely considered the poorest in the Western Hemisphere. Disaster relief experts estimated that 230,000 lives were lost during the earthquake and in its aftermath. Later in the year, another disaster struck Haiti: a cholera outbreak. In mid-November, more than 900 people were dead from cholera and another 14,000 were hospitalized.


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