When designing a circuit, it is important I do not exercise the same body part consecutively, unless performing a circuit, which will overload the endurance of one muscle group being trained. If the circuit is not one muscle group specific then the sequence of stations should be varied, for example; arms, trunk, cardio-vascular, legs, arms, trunk, cardio-vascular etc. This way of training makes exercise varied and therefore I am more likely to find it more interesting and will be more likely to keep doing it.
It also means that all muscle groups can be trained. This is very important as most muscle groups are used in tennis and circuit training will provide general conditioning. With regular testing, improvements in fitness are easily visible through circuit training as previous results can be compared with the current one. It is also possible to make a skill specific circuit for your sport. For tennis, this involves a series of drills within a circuit, on the tennis court. This will improve all skills because at each station, a particular skill is focused on.
Strength training Weight or resistance training is the ways in which I can achieve strength gain. It can be used to develop several components of fitness, including strength, strength endurance and explosive power. Which of these are stressed at a particular time depends on the weight or resistance, the number of repetitions and the number of sets. In tennis, when maximum strength is required, for example in the service (explosive strength) training methods, which increase muscle strength, will be required. This will include some form of relatively high resistance, low repetition exercise.
It is important to realise the following for power development; 1. That the movement and contraction period must be explosive to ensure that the muscle works rapidly 2. To use very high loads or resistance which will encourage the muscle to recruit all its motor units 3. To ensure the muscle recovers fully between sets, enabling the relevant energy source to recover. In tennis, strength endurance is also very important, and I should include it in the training programme. It is important particularly in a rally, as a lot of strength is needed to endure every shot. A different approach to training will be required. A lighter weight should be used, to enable more repetitions.
Increasing resistance will increase my pure strength, and decreasing resistance will allow for the development in speed. Increasing repetitions will increase strength endurance, which is what I need to improve. The degree of resistance is quoted as a percentage of the repetitions maximum (RM). I.e. the maximum load that can be moved correctly with six repetitions. For example, 15 X 50% RM for strength endurance.
Plyometrics Plyometrics enables muscles to generate more force in contraction when they have previously been stretched. Plyometrics takes the muscle through an eccentric (lengthening) phase before a powerful concentric (shortening) phase. This stimulates adaptation within the neuromuscular system whereby the muscle spindles within the muscle causing a stretch reflex. Muscle spindle apparatus are very sensitive receptors, which exist between skeletal muscle fibres, to help control the muscle movement smoothly and safely. They relay information via concerning the state of muscle contraction and the length or extension of the muscle. When a muscle is stretched, the spindle is stretched and it sends and it sends an impulse to the spinal cord, indicating how much and how fast the muscle has stretched.
If stretched too far, the muscle spindle apparatus will alter tension within the muscle and cause a stretch reflex, whereby the muscle is automatically shortened. In plyometrics, the quadriceps lengthens quickly upon landing. The spindles detect the lengthening and send afferent impulses to the spinal cord, which then relay motor neurones to the quadriceps initiating the stretch reflex causing a very powerful shortening of the muscle group and enables the athlete to bound upwards. This prevents muscle damage and produces more powerful concentric contraction of the muscle group. Power is determined by the force exerted by the muscle (strength) and the speed at which the muscle shortens:
Power = Force X Velocity This means that by improving either strength or speed of shortening, power may be improved. Plyometrics improves the speed at which muscle shorten. Mobility stretching This is a type of training to improve flexibility. Flexibility is a range of movement at a joint. Effective flexibility training can improve performance and reduce the possibility of injury. During repeated and regular stretching muscle tissue has been shown to elongate. There are two types of stretching; 1. Active stretching- the athlete holds the stretch for a period of 30-60 seconds. By consciously relaxing the target muscle at the limit of the range of motion. Muscle obligation may occur following regular contraction.
2. Passive stretching- this is the range of movement that can occur with the aid of external force. This is general performed with the aid of a partner, but resistance can also be offered through gravity and body weight. Stretching should only be performed after a thorough warm-up where an increase in body temperature has occurred. This can be done by a period of light cardio vascular exercise, centring on the muscles groups to be stretched. This can be done by a short, light intensity jog.
There are a variety of flexibility techniques that I may include in my training programme: Proprioceptive neuromuscular facilitation (PNF) is a method of flexibility training emerged from passive stretching. This decreases the reflex shortening of the muscle being stretched, which now occurs when a muscle is stretched to its limit. Here is one PNF technique; 1. Move slowly to the limit of my range of motion with a help from a partner.
2. Just before the point of discomfort, isometrically contract the muscle being stretched for between 6 and 10 seconds. 3. After the hold, the muscle will release, having stimulated the golgi tendon organ response that causes further relaxation of the muscle with the aid of a partner. PNF stretching relies on the fact that when a muscle contracts isometrically when stretched, the stretch reflex mechanism of the muscle spindles is switched off, and therefore enables the muscle to stretch further than before. A new limit of the muscle stretch may occur but athletes should not stretch beyond the slight discomfort.
There have been studies conducted that show athletes may only replace 29% of the fluid that they lost during practice or a game. One problem may be that water can sometimes shut off the osmotic drive (thirst mechanisms) that you get for drinking. As little as 1 pint of water can turn this mechanism off even though you may have lost 4 pints of fluid. Also, this doesn’t help replace the electrolytes that were lost through the sweat. Average sodium concentration in sweat is around 3.6 grams of sodium per liter of sweat. Cramp prone athletes may lose 6 grams of sodium per liter of fluid. As you can see water may be only part of the answer to restoring proper hydration to your body. Somehow you have to replace the sodium, potassium and other electrolytes that were lost as well as the fluid.
New research has shown that drinking flavoured water or sport drinks has proven to be a better hydrator than just plain water. This is because I am more likely to drink a fluid and continue to drink when it tastes good or it has a flavor to it. Sport drinks are superior to flavoured water because they provide the electrolytes as well as taste good. Sport drinks are also less likely to shut off the thirst mechanisms because it provides low amounts of sodium, which may actually elicit a thirst response. As I will be doing regular exercise during the training programme, re-hydration is vital because it only takes 1-2% dehydration to affect performance. Drinking plenty of water throughout the day and replacing fluids at practice with a sports drink will suffice this.