Danny O’Dell’s

Explosivelyfit Training News

Strength and power knowledge

15-May-06

ISSN: 1550-2643: Library Of Congress, Washington D.C.,

Welcome to this edition, I hope you enjoy the contents.

You are an athlete and interested in keeping yourself strong. This is strength training information. Do your friends a favor and forward this or refer them here so they can sign up too.

Topic discussed:

     Explosive Strength Testing

     Discovering the optimal level of energy

Explosive strength for all intents and purposes is the ability of the muscles to create significant high levels of neuromuscular tension in the shortest possible amount of time (Verkhoshansky, Y. V.). ‘Move the curve to the left’ is the key phrase we use in the WeightRoom Gym.

This testing variation in strength output measures the explosive strength of the lower body which displayed by jumping or throwing trials. The jump and reach test is generally the first to be measured in most schools and athletic training facilities simply because it is the simplest to judge and measure.

Equipment needs are minimal and can be as basic as chalk and a high wall. More elaborate apparatus may also be used. These measuring devices consist of the tall pole with flagged indicators that are pushed to the side upon contact with the outstretched hand of the athlete.

The most common methods of testing are flat footed and pre run up. In the each case the athlete faces, and stands flat-footed 4-5 inches from the wall. With an outstretched arm and chalk in the hand a mark is placed on the wall as high up as the athlete can stretch.

After this initial mark is made the test starts with the athlete turning sideways to the wall.

If performed flat-footed the athlete bends at the knees while swinging the arms backward and then following through with an explosive jump up as high as possible. At the highest point a mark is made on the wall with the fingers, which have been covered with chalk dust.

In the pre-run trial the athlete steps back two to three paces and then runs forward two to three steps before planting both feet and jumping as high as possible while touching a high point on the wall.

If using one of the flag devices the start is the same for both methods. The difference is there is no chalk because the athlete moves flag style indicators on the pole instead of making chalk marks on the wall. The start is the same, i.e. flatfooted with outstretched arms making the initial marker. This is followed up with either the flat-footed or the pre run technique of moving the indicators to determine the height.

Measuring between the first and the second marks or flag indicators scores the test. In all cases, a rest of between 1-5 minutes is taken before repeating the test again. The better of the two scores is recorded.

This quick and easy to conduct explosive test provides a rough estimate of the athletes proportions of fast twitch fibers.

A more precise method of determining fiber composition is with laboratory equipment. But here we are speaking of high costs for the measuring instruments. These tests electrically stimulate the muscle and then measure the electrical potentials and the force generated by the muscle. Then four separate times are noted:

1.    Time to reach or generate 50% maximal force

2.    Time to reach maximal force

3.    Time to go back to the 50% maximal force

4.    Time to the initial level

The test is based on a known standard of muscle fibers time and speed in reaching its peak maximum and decline in force. A fast twitch does this in 30 ms whereas slow twitch fibers take 80 ms to achieve these rates in force production and decline back to initial levels.

The critical times in these measurements have been found to be times of contraction and decreasing levels of force. Fast twitch fibers excite at a rapid rate and relax much faster than do slow twitch muscle fibers.

Upper body explosive strength is tested with medicine ball throws. The test begins with the athlete on their knees. From the kneeling position the ball is thrown from the back of the head, over and forward as far as possible. Women throw a ball weighing 4.4 pounds or 2 kg. The men use balls that are 6.6 pounds or 3 kg. Obviously the equipment needed for this test is minimal and should be in every strength coach’s gym.

Discovering the optimal level of energy

An athlete who knows what level of energy works best is at a distinct advantage over the one who does not. Overly systematic energization leads to nervousness, excessive muscle tonus and too much aggressiveness in situations where it is not warranted.

The reverse side of the energization equation is that of the under responsive athlete. They have a hard time finding the right intensity to perform at their peak.

Figuring out the right amount to do your best is a matter of learning from past performances. Pick out three of the best, and three of the worst. Now write down what your anxiety level was in each case. Now continue by noting what the muscle tension, heart and respiration rates were at these specific times. Use a scale of one to ten with one being the low end and ten the high end.

Once these have been noted then it’s up to you and you and perhaps you and your coach to decide the best numbers to focus on for future competitions.

That’s all for this time.