Dance is an art form that is skill and performance based, however fitness training is essential to ensure that the dancer can perform at their optimum and prevent injury. Physical performance in contemporary dance is dependent on a number of contributing physiological factors, which change in need, depending on the specific physical activity involved. These factors include aerobic and anaerobic fitness; muscular endurance, strength, and power; muscular flexibility/joint range of movement; motor skills (technique); and postural control. Dance is not a steady state activity and challenges many aspects of fitness at one time. Like the nature of dance, the DFI aims to address these fitness aspects simultaneously through the choreography, relating dance fitness components to the movement skills required in dance. It is hoped that through doing the DFI, dancers may identify what areas of their fitness need addressing, so that they can train specifically to improve their fitness and physical dance performance.
Anaerobic and Aerobic Fitness
There are two anaerobic systems that work primarily without oxygen, and one aerobic system that works almost exclusively with oxygen.
Anaerobic literally means “without oxygen”. The first anaerobic system, the phosphocreatine system, produces a surge of high intensity energy rapidly. Energy is derived from creatine, a chemical compound present in muscle fibre that is capable of producing high intensity activity that lasts for a matter of seconds before the “instant” supply is exhausted. A good example of this in practice would be a 100 metres runner, working at 100% for 9-10 seconds. There are few moments in dance when this system would be employed.
The second anaerobic system is capable of producing moderately high intensity activity (60-90% max) that can be sustained for between 30 seconds to up to two minutes. Energy is derived from anaerobic glycolysis; the waste product is lactic acid. When fitness levels are low, or intensity high, increased production of lactic acid, due to a lack of fitness demanded by activity, will impair muscle function. The circulatory system is unable to remove the build-up of lactic acid (lactate in the blood) sufficiently quickly to allow continued quality and intensity of movement. Therefore, in high intensity dance routines lasting several minutes, anaerobic glycolysis may be unable to provide the level of energy required to perfect movement. If intensity is lowered sufficiently, the aerobic system will begin to balance the lactic acid removal, but the level of activity must lower. The anaerobic system of energy production will be primarily utilised in the strength/endurance of muscle groups, for example, press ups, leaps, and other medium to high intensity muscle work.
Interval training is an excellent way of training the anaerobic systems; it involves training at a very high level (70-90%max) for a short amount of time, followed immediately by a low intensity, recovery, movement. This pattern is then repeated several times. A representative graph would show a peak and a trough. Regular training will encourage the body will adapt to cope with working at a higher level, with a quicker recovery rate.
Aerobic simply means “with oxygen” and involves the uptake, transport and utilisation of oxygen, combined with glucose circulating in the blood, to release energy and deliver oxygen via the lungs, heart and blood vessels, to the muscles. This biochemical process is known as Krebs cycle. Producing energy purely via the aerobic metabolism is non-fatiguing. The waste products of aerobic metabolism are carbon dioxide (CO2) and water (H2O). Energy expenditure is proportional to fitness levels; through training, the muscles of fitter dancers have an increased ability to produce energy aerobically for longer, before having to resort to producing energy using the anaerobic systems.
Through training aerobically, the brain and muscles will work more efficiently and for longer than the less fit. The non-fatiguing aerobic system delays the onset of the impairing anaerobic system. Training aerobically will also lower the resting heart rate, and will therefore allow a higher level or a longer period of exercise to be undertaken without employing the anaerobic system.
Aerobic training consists of sustained and regular activity, with an increased heart and breathing rate, at a slightly higher level of intensity than accustomed to, but below a level that produces physical discomfort – from 40-60% effort. An improved aerobic system can benefit the dancer in many ways other than those already stated above, e.g. a faster recovery rate between dance sequences; an ability to carry out exercises at a high quality, enabling more focus on the performance; boosted immune system; a healthier heart; higher concentration levels; increased energy levels in general; and in turn reduced risk of injury.
When physical workloads increase and incorporate anaerobic activity, which requires the dispersal of increasing levels of lactate in the blood stream, oxygen and glucose delivery to the brain becomes limited. The DFI highlights this by visual evidence of examples of physical and mental weakness, for example when the dancer cannot remember direction, is falling behind the musical beats, or is unable to hold a balance and many more. A healthy aerobic system = a healthy brain!
Muscular strength, power and endurance
Pure muscular strength uses the formula of one repetition maximum (x1RM) – the ability of an individual to perform a task using high resistance on a specific muscle (or group of muscles) once and to maximum effort. Some female dancers believe that strength training may diminish their aesthetic appearance by developing large bulky muscles; however aesthetic changes may be positive as pure strength training is not the aim. Careful and appropriate strength training can reduce body fat, and not hypertrophy muscle groups. However, hormonal status (testosterone levels) and the muscle fibre profile and diameter are factors.
Strength, core control and dynamic training can enhance physical performance, prevent injury through supporting weak connective tissues (such as those seen in hypermobile dancers), promote balance between antagonistic muscles, and increase bone density guarding against osteoporosis. Strength and flexibility are related in a positive way – one without the other would prevent optimal performance. Provided that strength exercises take the muscles through their full range of motion, and the dancer stretches after strength training, muscles will be strong, and flexibility will not be negatively affected.
Categories of specific muscle work include: muscular endurance, maximal strength, and muscular power (strength x speed) or dynamic training. Strength training can be performed in a variety of different actions – isometric (static), concentric (shortening of muscle fibres}, eccentric (lengthening of muscles fibres), all of which, when being performed, involve an appropriate resistance and speed. Improving muscular endurance entails high repetitions x low resistance; strength can be trained using high resistance x low repetitions; whereas power uses strength x speed. Muscular power is also known as speed strength, and is the ability to transfer energy into force quickly. Power can be seen in explosive movements, such as jumps in dance.
Plyometrics is a proven power-conditioning programme, however it must be done with care and under supervision to avoid injury. Training should be done in phases (starting with endurance, followed by strength, then power) to ensure the muscles are prepared for the increased demand. Overload is a vital and important principle to be employed to increase strength. Periodisation is also required for all methods to allow the muscle fibres to rest, recover and adapt, and to avoid overtraining.
Plyometric training should focus progressively on: landings, then take off, then rebounds. Foot work should follow a 2-2 pattern, then develop gradually to 1-2, then 2-1, and lastly 1-1.
Flexibility and Range of Movement
The term flexibility is often misunderstood. Contemporary dance (and most other forms of dance) require a large range of movement (ROM) of many joints and muscles of the body. The ability of an individual to have a large ROM within these areas depends on the joint structure, quality and content of the connective tissue that surround every single muscle and joint of the body. Connective tissue is known as the “organ of shape”, and also relates to postural control. Without adequate ROM, it is likely a dancer would not consider him/herself to be technically excellent. Criteria for achievement within this element is difficult to create since genetic influence is very strong.
Optimal muscle flexibility and joint mobility (MFJM) usually indicates that there are no abnormalities. Joint factors contribute to approximately 85% of MFJM; musculo-tendinous factors account for only 10%; and other factors including age, gender, hormonal balance, body type, body fat percentage, fitness levels, environmental temperature, psychological stresses, and warm-up, are responsible for the remaining 5%. Joint factors are genetically determined, and flexibility training prior to the completion of bone development may cause irreparable damage.
Musculo-tendinous factors relate to the length and concentration of fibrous and elastic connective tissues within the muscle, tendons (and ligaments). Connective tissue content is genetic, but short tissues can be improved by concentrated training. Soft tissue injury, if not treated carefully, could result in the increased deposition of collagen, which if not effectively mobilised may result in scar tissue, and be detrimental to flexibility.
Flexible dancers’ bodies are able to withstand considerably more stress than non-flexible dancers, therefore knowledge-based flexibility training is vital and can safeguard against injury and improve quality dramatically. An important factor to consider, however, is hypermobility (excessive joint ROM) that is not uncommon in dancers. This often relates to weak, unstable joints that are more prone to injury. Hyperextension of the knee is often thought of as a desirable aesthetic in dance, particularly in classical ballet, however hypermobile dancers can be difficult to train due to a lack of proprioception (perceiving where the joints/limbs are in space). Development of muscular strength and core control to help support unstable joints, correct placement and safe range of movement, should be the focus to increase, or control, joint flexibility, body awareness and proprioception. Core control of major joints – pelvis, rib cage and spine, knees, shoulders, ankles, is vital if flexibility training is to safely enhance the dancer in the short and particularly the long term.
Motor or Proprioceptive Neuromuscular skills
Speed, agility, co-ordination, control, balance, reaction time, memory for choreography, spatial awareness, and directional changes, are just a few of the many motor skills that dancers require. These elements relate directly to the ability of the mind to connect to the body, quickly and accurately. The sensory and motor nerves speedily receive and deliver information. When fatigue is setting in and aerobic energy production is impaired, any or many of these elements may become impaired. The brain functions on glucose and oxygen for its energy supply, when this is depleted, all the above become more difficult to perfect.