The Depth Jump(跳深训练研究专题)
[img]http://www.digthisvolleyball.com/training/images/sdj.jpg[/img]In this issue’s ‘exercise of the month’, it’s time to take the plunge – quite literally. As PP regular John Shepherd explains, the depth jump is a plyometric exercise that almost all athletes can benefit from.
Main muscles involved: quadriceps (thigh), hamstrings, glutes (buttocks), calf muscles.
Joint motion: ankle extension, knee extension, hip extension.
Sports applicability: running (sprinting, middle and long distances), all running and jumping based sports such as tennis, football, basketball and high jump etc.
Muscular action
The depth jump is a plyometric exercise. Plyometric exercises work on the principle that a concentric muscular contraction is much stronger if it immediately follows an eccentric contraction of the same muscle. (Eccentric muscular action occurs when a muscle lengthens under load – eg the lowering phase of a biceps curl. Concentric muscular contraction occurs when a muscle shortens under load.)
The effect of a plyometric exercise is a bit like stretching out a coiled spring to its fullest extent (the eccentric contraction), then letting it go (the concentric contraction); large amounts of energy are released in a split second as the spring recoils.
Conditioning benefits
General – The depth jump provides a great base of dynamic power for the majority of sports. This is because it closely matches the sport specific speeds of movement and muscular action. Most standard weight training lifts, even when performed as quickly as possible, take 0.5-0.7 seconds to complete, whereas during a depth jump your feet may only be in contact with the ground for between 0.2 and 0.3 seconds.
Sport specific – Although the basic depth jump is very sports specific in itself, it can be made even more so by adaptation and variation (more later).
Start position
Stand on top of a strong platform 0.5-0.8m high (the greater the height, the greater the strength component, the lower the height the greater the speed component).
Action
1. Step slightly forward off the platform. Land toward your forefeet;
2. React as quickly as possible to the ground and spring immediately back up into the air;
3. Use your arms to add to your speed by drawing them back prior to stepping off the platform and swinging them vigorously upward as your feet hit the ground;
4. Keep your back in neutral alignment, ie not arched or rounded;
5. Focus your gaze straight ahead of you.
Training tips
* Maintain neutral posture and a balanced elevated chest position throughout the exercise. Do not attempt to absorb the landing on impact, rather react as quickly and as fast as you can, even if this sacrifices height gained;
* The faster a muscle is forced to perform an eccentric contraction, the greater the concentric force it can generate. To help your understanding: think of a rubber ball being thrown against a wall. What happens when the ball is thrown harder? It springs back even faster and further. This is the effect you are looking for when performing plyometric exercises, like the depth jump;
* Always warm up thoroughly before performing depth jumps;
* Don’t perform more than two workouts a week and allow at least five days before important competitions;
* Monitor the number of jumps performed. Depth jump volume is measured in ground contacts; avoid more than 60 in a session. Start with 3 x 6 repetitions;
* To allow your power-producing fast-twitch muscle fibres to be at their most effective, take 30 seconds recovery between exercises and two minutes between sets;
* Perform depth jumps on a non-slip flat surface – a sprung gymnasium floor or an all-weather athletics track are ideal surfaces;
* You need to be in ‘the right frame of mind’ to get the most out of depth jumping. Going through the motions will not turn on sufficient neuromuscular input to optimise their performance.
Sport specific exercise progression
Single-leg depth jump (hop) for distance
This variation will up your leg muscles’ power and is a great exercise for field and racket sports players, sprinters and jumpers (where all movements are performed with an independent leg action). Note the single-leg depth jump places greater potential strain on the legs and back, as such this exercise should only be performed by those with a high degree of prior plyometric training experience.
Assume the same starting position as for the first exercise, but this time drive forward to land about 1m in front of the platform, on the same leg. React as quickly as possible to the ground and hop forward as far as you can. Maintain an upright posture and cycle your hopping leg under your body whilst in the air. Coordinate your arms with your legs, ie in a running, ‘opposite arm to leg’ style. Try 3 x 5 repetitions, alternating left and right leg sets.
John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper
Illustrations by Viv Mullett
[[i] 本帖最后由 bing2008 于 2008-4-13 04:20 PM 编辑 [/i]]
Drop Jumps and Depth Jumps
- Shock Yourself into high gearWhen you hear the phrase "Russian training secrets" what do you think of? Back in the early 1970's you probably would have waited in anticipation to hear the training secrets that allowed the soviet union to so thoroughly dominate competition in the olympics. Fortunately, now it's 30 years later and the old Russian training secrets have long since been revealed, - but even today that phrase will still set many people on the edge of their seats.
The Russian secret I'd like to talk about and the same one that in large part made the soviets such a dominant force on the world competition scene back in the 70's is called the shock method of training. The shock method consists of 2 very simple exercises that really don't even require any equipment, depth jumps and drop jumps.
Both of these exercises are now commonly lumped into the plyometric family of exercises and were developed by Soviet scientist and coach Yuri Verkhoshansky. The original meaning of the word plyometric (originally spelled pliometric) was intended to mean eccentric contraction.
These exercises rely on forceful eccentric contractions and were used by Soviet coaches as a "shock" method to take speed-strength ability to a new level. The neuromuscular effect is similar to hooking your muscles up to a power plant and injecting them with a very brief high current. In fact, these exercises were credited as being the secret weapon in the training of the great Soviet sprinter Valery Borzov who dominated the 100 meter dash.
Plyometrics became popular in America in the 70s. Soviet sprinters were displaying very impressive sprint times so U.S. coaches decided to go to the Soviet Union to figure out what the Russians were doing. The Americans saw the Soviet athletes stepping off of high boxes, hitting the ground, and jumping back up in the air. Upon their return to the United States, they spread the word of the magic training method and the term "Plyometrics" was coined. Soon all types of leaping and bounding drills were thrown into the same category as the original shock plyometric exericises and before long every coach in the world was using some type of supposed plyometric activity. Unfortunately, they never took into consideration the planning and conditioning that existed in addition to this type of magic training. In the Soviet Union the shock method was used in a cyclic nature which involved varying intensity levels and conditioning methods. Even today many coaches prescribe plyometric exercises without much of a thought of how they should be included in a plan.
How They Work
Recall that Force = Mass x Acceleration.
In normal training, the Mass is increased which leads to static strength development and muscular growth.
With the use of shock plyometrics, the Acceleration is increased which leads to target involuntary neuromuscular and central nervous system processes.
The ultimate goal in shock method training is to maximize the benefits of the stretch shortening cycle or plyometric reflex. You need sufficient strength in the musculoskeletal system before adhering to this type of training. A great deal of force is produced in the joints when performing any type of jumping or falling and one should concentrate on quality training.
Since shock methods increase plyometric capacity and the ability to use the stretch-shortening cycle they are beneficial for virtually any lower body explosive power movement including sprinting, jumping, agility, gymnastics etc. An experiment revealed that a group of track and field jumpers executing primarily depth jumps (all of them did 475 jumps) over a 12 week period showed greater improvement in reactive ability then a group which trained with traditional methods and executed 1472 general pushoffs (squats, squat jumps and hops with 90-95%, 70-80%, and 30-40% of 1rm and a total volume of 93 tons.
Execution
To perform a depth jump you stand on a box, step off, hit the ground, and immediately jump up as high as possible at ground contact. You should gain energy from the impact that you absorb, stabilize, and transfer to your muscles and tendons for a more explosive jump.
A drop jump is just the landing portion of a depth jump. You simply step from a box and "stick" the landing.
Differences
Although the 2 exercises both increase plyometric power and are very similar they do have a few differences. Nearly all sports movements rely to some extent on plyometric ability. Before you can put energy out you have to take energy in. After you take energy in from one direction you then have to put it out in the opposite direction. The drop jump trains more of the "taking energy in" aspect and the depth jump trains more of the "putting energy out" aspect. Because of this, drop jumps are more of a strength/force movement and depth jumps are more of a rate of force development and speed movement.
Many athletes will train only the takeoff part of a jump, with no concern for building up the capacities needed for a controlled and balanced landing. Athletes should be able to "stick" a landing, absorb the shock, and efficiently transfer that shock into a positive movement immediately.
Testing has revealed that for a shock absorbing landing with a knee bend, athletes use a resistance force 3 to 4 times their body weight. Landing performed with stiff leg joints requires a force of six to 8 times bodyweight. An athlete weighing 132 pounds requires 400 to 500 pounds of force to absorb the shock of landing. The same athlete requires 700 to 1000 lbs to land with the leg joint stiff. When an athlete lands on one leg, as in figure skating, the force at the instant of landing is 3 to 4 times bodyweight for a shock absorbing landing and five to 7 tmes when landing with stiff legs. Dealing with forces like these requires a substantial level of eccentric strength.
Both shock jumps and depth jumps will build up your reactive power which is the ability to generate the force of muscular activity immediately following a landing or the absorption of force. Drop jumps and regular strength training work well to build up plyometric capacity on the max force side of things and build landing strength or the ability to absorb and stabilize force. This trains eccentric strength or the "taking energy in" aspect. Depth jumps work to increase what happens after the force is put into the system, or the "putting energy out" side of things.
Force In vs Force Out
Watch the difference in contact times and the speed at which people change direction from "down" to "up" or from negative contraction to positive contraction when they run, jump, or cut. Depth jumps will shorten ground contact times during the amortization phase (the switch) and improve the rate of force development and velocity that occurs after the transition. Drop jumps will heighten the amount of force we can take in at the transition which will give us more potential to put force out.
So, for someone who's limiting factor is force absorption or strength, drop jumps are a huge benefit. This type of athlete won't be able to change direction quickly because they won't be able to stabilize the negative force to begin with. Think of someone who is the direct opposite of Barry Sanders. For someone who needs speed out of the transition, depth jumps are a better choice. In fact, when it comes to pure speed, a study revealed that the max speed in a sprint correlates best to how much force one can put out in the first .100 (1 tenth of a second) of a depth jump.
If your best vertical jump from a regular standing position is better then your best depth jump from even a very low box height (~ 8 inches) then you should use landings via drop jumps to increase your ability to gather energy and optimize force absorption capabilities. If your depth jumps are higher then your regular standing vertical jump then you are a good candidate for depth jumps. However, nothing is cut and dry here. There is considerable overlap with these training methods so sometimes the drop jump will be used if a person is slow during transition due to inefficiency at absorbing energy.
Strength Recommendations
It has been stated that an athlete should be able to squat 1.5 x times their bodyweight before performing shock plyometrics in order to avoid injury and optimize progress. One thing that must be made clear is that these training methods originally called for box heights of 1 meter or more. When absorbing the force from this type of landing it is necessary to have a high level of strength. Realize you probably won't get much benefit from any plyometric exercises until you have a base level of strength. However, even little kids jump off of playground equipment and furniture all day long without injury. My recommendation is that you should not perform depth jumps from a box height of greater then 18 inches until you can squat 1.5 x or more your bodyweight. However, it is perfectly fine to perform drop jumps from a height equivalent to your best vertical jump regardless of your strength levels. In fact drop jumps combined with general strength training are a great tool to not only increase your eccentric strength and ability to deal with high forces, but also teach basic movement mechanics with force.
Box Height Recommendations
All sorts of box height recommendations are thrown out for depth jumps and the original recommendations called for box heights of .75-1.15 meters. A very simple and effective box height recommendation is to perform your depth jumps from the height of a box that allows you to jump the highest immediately after ground contact. As stated earlier, if you can't perform a depth jump from a box of any height and get up higher then you can in a regular standing jump then you shouldn't be using depth jumps to begin with. One should aim to increase the speed, acceleration, and height of the jump before increasing the drop height. According to the founder of shock method training,Verkhoshansky, you should not spend in excess of 0.2 of a second on the ground after landing.
Drop jumps should be done from a box height that enables you to absorb the most energy without faltering. Aim to "stick" the landing soft and silent on the balls of your feet just like a gymnast doing a dismount. If the heels hit the ground the box is too high and if there is a thud at impact the box is too high. When the box is the correct height the jump should be silent and soft with a reflexive gathering of energy and often a reflexive bounce at impact. When your body is gathering energy efficiently you will feel your system want to reflexively use that energy to advance out of the landing. Generally a good starting point for drop jumps is from a box 20% higher then the best vertical jump and eventually on up to 1.15-1.25 meters.
Performance Recommendations
Both variations of shock training should be performed on a surface that has some give to it to avoid injury. Grass works well as does the use of solid rubber mats. You should land as far away from the box as the box is high. So, if you're standing on a 30-inch box you should land approximately 30 inches away.
When executing depth jumps you should use a simple athletic stance position just as you would whenever you jump.
Drop jump performance can vary. You can land in a regular athletic stance for general carryover, in a stiff-legged stance to emphasize lower leg force production ability, in a 1/2 squat to emphasize the hips and hamstrings, in a split squat stance to emphasize all around balance, and in a 1-legged stance to heighten the magnitude of force absorbed.
Volume Recommendations
The optimal dosage of depth jumps or drop jumps should not exceed 40 combined ground contacts per session for well conditioned athletes and 20 ground contacts per session for lesser conditioned athletes. As a guideline, the dosage of shock plyometrics should not exceed 5-8 repetitions in 1 set and sets of 3-5 work well with up to 30 seconds between reps and up to 10 minutes between sets. Remember that these are a speed-strength tool not an endurance tool. Maximum muscular recruitment requires that you stay fresh. High volumes of consecutive repetitions are not possible or advisable.
Using the above volume shock jumps should be performed once or twice per week in training sessions devoted to specialized speed-strength or strength training.
For best results use the above recommended volumes of shock jumps in short 3-4 week blocks preceeded by a block of higher volume strength training. Another option for someone who already has a great deal of strength is to perform a block of drop jumps in conjunction with strength training, followed by a block of depth jumps and power training, followed by another block of shock jumps with general explosive exercises. The set-up would be performed twice per week and look like this:
Week 1-3 Low level drop jumps/Strength (squat)
Week 4-6 Depth Jumps/Power training (speed squat)
Week 5-7 Drop jumps/General explosive bodyweight exercises
Depth jumping variations give quick results but the gains are just as quick to plateau. Low level variations of drop jumps can be used throughout the year but it's best to really focus on shock training 2-3 times through the year when you need to bring your level of speed-strength to a peak.
-Kelly
跳深的网上视频
请看[url]http://www.youtube.com/watch?v=hb4JwBNY56s[/url] 超等长练习机制与跳深训练法研究述评
A Review on the Studies of Ploymetric Exercise Principle and Jump Drop Training
<<天津体育学院学报 >>2005年02期
罗炯 , LUO Jiong
通过对国内外有关超等长(Ploymetric)收缩机制的研究回顾,提出了训练对象的力量基础、训练水平、体重、训练负荷等差异决定了超等长训练方式的特殊性.跳深作为发展运动员下肢爆发力的一种超等长练习的代表,其高度选择、动作的变化、负荷强度等可变因素必须与具体运动专项相结合,遵循区别对待原理, 才能有效地发展运动员的专项力量素质. 跳深练习对增加运动员腿部爆发力作用的研究
The Research about the Effect of Depth Jumping Exercise for Increasing Athlete's Legs Power
<<体育与科学 >>2002年05期
郑彩壮
跳深练习是力量练习中的一种肌肉的超等长练习,很多教练员认为这种练习能够有效地提高运动员腿部爆发力和弹跳能力,因此将其作为在训练中经常采用的手段.但是也有很多研究表明,这种练习的效果并不优于其它一些发展腿部力量的练习,而且跳深练习还容易造成运动员的肌肉损伤,建议教练员在选择这种练习时要慎重, 特别是面对训练水平较低的青少年运动员. 跳深练习对提高爆发力训练效果的实验研究
Experimental Research on the Training Effect of Practicing Longitudinal Springing on the Improvement of Explosive Force
<<沈阳体育学院学报 >>2004年05期
贾桂云 , 张芝贤
通过采用有反向引导动作和无反向引导动作伸展跳跃的练习以及新式跳深练习方法的试验,结果表明运动员弹跳能力都提高了20％～30％.相反采用传统训练方法的对照组成员的弹跳力却没有明显的变化,认为新式跳深练习能使弹跳力提高. 不同高度间距组合跳深练习与起跳效果的非线性关系分析
The Nonlinear Analysis Between Drop-Jump of Different Depth and Distance Combination and the Effect of Jump
<<天津体育学院学报 >>2006年06期
部义峰 , 李世明 , 韩静 , 熊安竹
跳深练习是一种发展肌肉爆发力的有效形式,在理论和实践上的应用不断深入,特别是对跳深高度的研究颇多,而对跳深间距的研究却很少,不同高度、间距组合跳深练习的研究国内未见报道.因此,在通过实验条件下获得不同高度、间距组合跳深练习对踏跳效果的影响程度,以及不同组合跳深练习与踏跳效果间的非线性关系, 进一步丰富跳深练习的方法,更为深入了解二者关系,为跳深练习更加广泛的应用提供方法、理论上的依据. 不同高度间距组合跳深练习与起跳效果的非线性关系分析
The Nonlinear Analysis Between Drop-Jump of Different Depth and Distance Combination and the Effect of Jump
<<天津体育学院学报 >>2006年06期
部义峰 , 李世明 , 韩静 , 熊安竹
跳深练习是一种发展肌肉爆发力的有效形式,在理论和实践上的应用不断深入,特别是对跳深高度的研究颇多,而对跳深间距的研究却很少,不同高度、间距组合跳深练习的研究国内未见报道.因此,在通过实验条件下获得不同高度、间距组合跳深练习对踏跳效果的影响程度,以及不同组合跳深练习与踏跳效果间的非线性关系, 进一步丰富跳深练习的方法,更为深入了解二者关系,为跳深练习更加广泛的应用提供方法、理论上的依据. 跳深跳远与三级跳远跨步跳起跳的动力学比较研究
Kinetic Comparative Study on Taking-off of Depth-long-jump and Long Jump
<<北京体育大学学报 >>2005年07期
王薇薇 , WANG Wei-wei
采用文献研究及在实验条件下的动力学测试,对两步助跑跳深跳远练习与三级跳远跨步跳起跳力量在形式及内容上的相似程度和差异点进行对比分析.结果显示,两步助跑跳深跳远练习可以作为发展三级跳远跨步跳起跳力量的专门训练手段. 跳深纵跳练习对跳高运动员起跳腿"承受能力"的测定与分析
Measurement and Analysis on Enduring Ability of Jump Leg as Adopting Deep-jump and Vertical-jump by High Jumpers
<<沈阳体育学院学报 >>2006年01期
刘建 , 李世远 , LIU Jian , LI Shi-yuan
采用运动学和动力学相结合的生物力学研究方法对跳高运动员下肢肌的承受能力进行研究,得出如下主要结论:①跳深纵跳练习可以作为提高跳高运动员起跳能力的专项练习;②跳高运动员起跳腿的承受能力直接影响缓冲和蹬伸过程,并最终影响起跳效果;③膝关节和踝关节,尤其是踝关节是二级跳高运动员下肢承受能力的薄弱环节.同时膝关节是最大缓冲时刻的"关键性环节";④二级跳高运动员产生最大反跳高度的适宜高度为(35.0±4.56)cm,最大反跳高度为 (48.00±3.78)cm;⑤适宜高度跳深的冲击载荷与摸高成绩、适宜高度跳深纵跳的反跳高度与助跑摸高成绩均呈高度相关,两者均是评价运动员起跳能力的重要指标. 力量训练的发展动向与趋势
从运动生理学的角度分析， 力量训练主要应从 3 个方面满足或尽可能接近“专项”：1） 只有参与专项运动的肌肉在力量训练时被调动起来 ( 募集 ), 肌肉才有可能得到训练；2）只有肌肉的工作方式 ( 离心或向心工作 )和冲动频率 ( 收缩速度 ) 与专项一致，才能够使肌肉力量朝着专项技术的方向发展；3）只有肌肉或肌群之间的配合与专项技术特点一致，才能够将机体各环节的肌力整合，形成正确的“用力顺序”。在训练中， 只有注意了这三个方面的问题， 才能打造出良好的专项力量素质。
回顾和总结近年来专项力量训练的发展， 专项技术与力量训练的密切结合是有效提高专项力量水平的重要途径。许多运动项目，尤其是一些周期耐力性项目经常采用增加阻力的方式提高运动员的专项力量， 例如田径投掷项目的投重物练习， 赛艇的划重艇， 游泳的牵拉阻力游，自行车的增加传动比骑等等。
从训练的“适应”原理来看， 肌肉力量主要通过“负重抗阻训练” 得到提高。目前力量训练的主要方式仍然是通常被称作“杠铃的训练”的负重力量训练。这种类型的训练具有对神经一一肌肉系统刺激大， 训练效果好的优点，但却存在与专项技术不吻合， 不利于专项力量发展的缺点。所以， 如何将“杠铃房”的负重抗阻训练与专项结合，使神经――肌肉通过“负重抗阻训练”形成专项技术需要的力量体系， 发展运动员的专项力量， 成为所有运动项目在力量训练中最关注的问题。
对近年力量训练的研究成果和优秀运动员力量训练实践经验的总结与分析表明， 杠铃训练主要从下几个方面对运动员的专项力量能力进行支持和影响。首先，杠铃力量训练应从运动员的力量结构的层面上支持专项力量的发展。不同专项和不同运动水平选手力量素质的一个突出特点表现在力量结构的不同。力量不仅与其它素质之间有着密切的联系，而且本身又被分为多种拥有相对独立结构的力量子能力，如快速力量和力量耐力等。任何一个专项或项群均拥有对各自专项最重要的， 以某种子力量素质为主的“专项力量”。因此，杠铃力量训练不仅只发展一般的力量素质， 而且应重视力量向专项的靠近， 优先发展那些对专项成绩最具影响的力量能力。
ZATSIORSKY对两名不同专项的优秀运动员在 30－100% 最大力量负荷时杠铃卧推最大次数的测试结果显示，摔跤运动员的推举次数从最大力量的约 90% 开始明显多于举重选手， 这说明摔跤运动员比举重运动员在力量耐力上具有明显的优势。力量的专项化特征同样也反映在能量代谢的方面。笔者测试了男子跳远和长跑运动员 完成 5 组负重半蹲时血乳酸平均值的变化 ( 测试方法为：50% 最大力量负重， 每组 20 次深蹲 ( 膝角 90 度 ), 间歇时间 1 分钟 )：跳远运动员在第 2 组练习后血乳酸值的升高速度开始明显快于长跑运动员， 之后的每组练习两组运动员的血乳酸均值均呈显著性差异 （p≤0.01）, 长跑运动员表现出明显的“节省化”特征， 力量耐力水平优于跳远运动员。由此可见， 杠铃力量训练尽管不能精确地发展专项力量，但是可以帮助运动员建立专项最需要的力量结构， 使力量素质向专项所需要的方向发展， 例如培养举重运动员形成良好的最大力量素质，重点发展对短跑、跳跃运动成绩最具影响的快速力量素质等等。
其次，根据专项力量训练的原则,“杠铃房”的力量训练还应从练习方式和负荷两个方面解决“专项化”的问题。正确的练习方式可以使那些对专项技术最具影响的肌肉或肌群得到训练，例如同样的推举会由于杠铃运动的不同方向而产生不同的训练效果，一般的杠铃卧推主要发展胸大肌等胸廓前部的肌肉，而坐式上推则重点发展背阔肌和肋间肌等胸廓后部和两侧的肌群。又如， 杠铃训练中的深蹲和半蹲的主要不同点在于对臀大肌刺激程度的不同， 深蹲时臀大肌的参与程度较半蹲大，所以不同专项应根据下肢用力的发力角确定练习的手段，一些专项技术中动用臀大肌多的运动项目， 如速度滑冰，腿部力量的训练就应以深蹲练习为主，而一些跳跃项目， 如跳远和三级跳远， 则应以与起跳角相应的半蹲练习作为发展腿部力量的主要手段。
HAKKINEN,KOMI的研究显示，两组运动员采用不同的训练方法发展反应力量 ( 也被称作“超等长”力量 ), 由于训练方法的差异，使两组受试者得到了截然不同的训练效果。运用最大力量训练方法的 a 组训练前后的跳深成绩没有显著性变化， 而运用爆发力训练手段的 b 组跳深成绩有了显著提高。特别应指出的是，b 组在总训练量中约 60% 为跳深训练， 在跳深训练中又有 60% 的练习为 40 cm 高度的跳深， 所以在这一高度的提高幅度明显高于其它高度。该结果说明， 不同的力量训练方法和要求不仅对某一种力量能力的发展具有重要影响，而且对运动员完成动作的特定技术环节 ( 如起跳的关节角度 ) 具有塑造作用。因此， 应当注重力量练习的细节， 规范每一次练习的幅度、速度，使练习的过程尽可能与专项一致。
“训练负荷”是打造“专项力量”的另一个重要途径。力量训练负荷的主要构成因素一一练习的重量、速度、组次数和间歇时间直接影响到专项力量的形成，以专项的运动特点为依据制定杠铃训练的负荷是当前力量训练的一个主要发展趋势。根据 ZATSIORSKY 的研究， 世界优秀举重选手的训练负荷以重量大、组次数少为特点，80% 最大重量以上负荷占全年负荷的 61%, 挺举和抓举1-3次的练习组数分别占全年训练组数的 98.2% 和 94.6% 。
PAMPUS ,LEHERTZ,MARTIN等做了两组不同力量耐力训练组合的实验：间歇组和持续组均完成 100 次负重半蹲练习， 间歇组将其分成 4 组完成 ( 每组 25 次， 组间歇 4 分钟)， 持续组则将 100 次练习一组完成。 结果表明，2 组受试者的血乳酸平均值无论是在练习过程中，还是在练习结束后，持续组的血乳酸平均值均表现出明显高于间歇组。这说明不同的训练方法对运动员的力量耐力能力具有不同的影响作用。
自《力之源》 纵跳是跳跃运动的基础之一，在体育运动中占有重要的地位，是一切借助下肢运动的运动员在比赛中取得优异成绩必备的运动素质，目前在国外已受到广泛和高度的关注。在我国，对其有关方面的专门报道研究尚不深入和完善。因此，本文研究的目的是在对国内外有关纵跳训练文献研读的基础上，通过对构成纵跳运动能力的组成因素分析、归纳出提高纵跳能力的最佳训练方法，并以此制定出发展纵跳训练的周期性训练模式，挖掘人体潜能，提供科学的训练策略。
一、纵跳的用力特征及组成因素分析
运动员在体育比赛中纵向跳跃时，通过瞬间踝、膝、髋关节的快速伸展，臀部、膝部、踝部肌肉爆发式收缩，以及肢体的协调摆动，产生强大的起动力量，使身体快速蹬离地面。显而易见，它是以强大的下肢力量为基础的复杂多关节、多肌肉群的协调运动，而且，它对踏地支撑要求极高，既需要发展最大速率的起动式、爆发式收缩，又需要利用股四头肌和小腿三头肌的牵张反射，完成肌肉克制性退让收缩，以增加肌肉的工作距离和收缩速度，同时还需主动肌、对抗肌之间，各关节之间的协调配合，以及对抗肌的互补放松作为保障，产生强大的输出功率，有效地完成纵跳技术。由此可见，它主要由下列因素交互影响：下肢肌肉的最大力量；下肢快速力量包括快速起动力量和爆发力；促进肌肉快速收缩一伸展能力的反应力量；产生垂直速度的制动力量；完成动作时力量与速度的最佳匹配，即最大输出功率；参与运动有关肌群的协调配合能力；符合专项运动特点的有效技术动作(见表1)。另外，纵跳能力还受体重、年龄、性别、生物节律、训练水平、个性心理等因素的影响。
二、发展纵跳能力的训练方法特征
从笔者查阅到的资料看，目前国内外对有效地发展纵跳能力训练方法的研究；主要集中在以下几个方面。
(一)利用超等长工作原理设计的跳深训练方法
超等长收缩是指在冲击性较大的负荷作用下，肌肉快速完成拉长一缩短的循环过程，加速身体向上运动。在体育运动中如各种双脚、单脚跳跃运动，踏地支撑的摆动投掷动作，都是这种肌肉的工作类型。该肌肉的活动方式允许运动员用“补偿加速”引起强烈的牵张反射，产生超大的肌肉力量快速完成动作。
(二)组合练习方法
组合练习是指由类似发展专项运动能力的训练方法组合起来的练习。
(三)适宜负荷训练方法
从全面发展的角度看，大于80％1RM(能重复举起最大重量的次数)和轻于60％1RM的负荷，对发展纵跳能力都有不同程度的影响；从纵跳能力的组成要素在专项运动中表现出快速动作所占的权重看，练习中应尽可能用快速练习。另外，轻质快速练习较重质徐缓练习更有利于纵跳成绩的增长。
(四)举重运动训练方法
用举重运动的抓举、挺举，以及辅助练习的手推、手挺、爆发式抓举、上挺、提拉杠铃等，可作为发展纵跳能力的有效训练方法。
(五)变阻训练法
变阻训练是指在完成动作的过程中，根据肌肉长度一张力关系的不断变化，在专门设计的训练器上练习。
(六)等动训练法
是指关节在整个关节运动范围内，肌肉以衡定的速度进行最大用以收缩的训练。
三、建立纵跳练习的周期性训练模式
(一)建立纵跳训练方法运用效果的评判指标
为进一步探讨各练习方法对发展纵跳能力的最佳训练效果，笔者根据上述理论分析与专家咨询、问卷调查相结合的形式，从回收58份有效问卷中经分层加权计算，建立了纵跳训练方法与纵跳能力组成要素间的相关评判指标(见表1)。
从评判指标看出，不同的训练方法施加在不同的纵跳要素上，产生的效果不尽相同。因此，在训练中应针对运动员跳跃能力发展的不同特点，根据力量训练的特殊性原则，有针对性地练习，才能达到事半功倍的最佳效果。
(二)制定纵跳训练的周期性训练模式
为了能够持续、有序、高效、系统地发展纵跳能力，我们根据各类型训练周期的任务和上述的研究成果，制定出一个发展纵跳能力的周期性训练模式(见表2)。
1．准备训练周
该周的：主要任务是通过基础训练引起机体的生物适应，培养多种竞技能力。因此，该阶段的训练方法应采用大负荷的重量训练，增、加肌肉的力量，为下阶段发展起动、爆发、反应力量奠定物质基础。另外，通过肌肉体积增长导致力量的增大，比通过神经适应引起的力量增加会保持更长的时间。因此，肌肉的力量应在准备期发展，竞赛期保持，恢复期给予延续。此阶段一般采用的训练手段是：深蹲练习，腿部推举练习，以及加强臀肌、股四头肌、胭绳肌和腓肠肌各独立肌群的力量练习。
2．赛前训练周
该周的主要任务是，使运动员的机体适应比赛要求，把竞技能力集中到专项中去。因此，此阶段的训练中应采取更大负重的专项练习来发展最大力量，为进一步发展爆发力和超等长练习奠定基础，常用的训练手段是前深蹲、后深蹲练习，腿部推举练习等。训练时注意，上举的向心阶段应尽可能以快速爆发式完成，下放的离心阶段应尽量控制肌肉的用力方式缓慢完成，以提高训练效果，减少肌肉损伤。
3．比赛周训练
该周的主要任务是为培养理想的竞技状态作准备和调整，准备比赛实现目标。因此，该阶段选用训练方法的原则应是重点加强神经系统支配调节改善对肌力的影响，减少以增加肌肉生理横断面来提高肌力的训练方法。如采用轻质(30％～60％)、快速爆发式练习，超等长练习，举重运动练习，以及和专项技术特点、供能方式相似的组合或辅助性练习等。为保持前阶段训练已获得的累积效应，赛前5～6天不能停止训练，且每周应安排2次保持最大力量和爆发力的练习。
4．赛间期训练
现代运动竞赛的特点是比赛次数日益频繁增多，赛日时间延长。因此，如何处理系列比赛间期的训练，用通过比赛阶段短暂的自然适应来发展纵跳能力，越来越引起人们的重视。一般采用的训练方法是举重运动方法，轻负荷和各种跳跃相结合的组合方法。超等长练习方法应减少或取消。另外，视赛间长短，每个赛间期应有一次大负荷训练。
5．恢复周训练
恢复周的主要任务是用各种恢复措施消除生理与心理疲劳，促进超量恢复。因此，该阶段练习可选用小负荷的变阻训练法，等动力量训练法，以维持纵跳能力，促进训练中损伤组织的康复与再生，为下个更高的周期训练做准备。
四、结论
(一)纵跳能力是由许多因素的交互作用所决定。包括腿部肌肉的最大力量，力量发挥的最大速度，运动的神经调节，肌肉伸展一收缩的能力，以及各部分肌肉的协调配合等。
(二)利用超等长工作原理设计的跳深训练方法，组合训练方法，举重运动训练方法等，是发展纵跳能力有效的训练方法。
(三)应根据运动员纵跳能力各组成要素发展水平的差异性，和不同训练周期的任务，有针对性地优选最佳训练方法手段，以达到整合最佳的训练效益。
(湖北师范学院)刘卫民 《田径》2005年第2期 体育运动-教学园地 佩服！ 佩服什么呢？你是什么专业的？ 感谢楼主的工作。
请问一下“squat depth jump”练习和“depth jump”练习，哪个对下肢爆发力的训练效果更好些呢？ 这个问题非常好，说实话，我自己不是很清楚。但是根据个人经历，前者是在膝关节有一定角度的情况下跳深，势必会动员更多的神经肌肉参与工作，而后者还应该分类，即直立跳深和屈膝跳深。当然了，屈膝跳深相对来说负荷更大。这个如果感兴趣的话可以做个实验，比如说：高度一致，不同屈膝角度跳深，对人体下肢肌肉力量产生什么样的影响。我觉得这个对硕士生做个论文还是有意义的。我的假设是：相同高度、屈膝跳深比直膝跳深效果更好。
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