Guest blog by Richard J Godfrey PhD FACSM FBASES, Centre for Sports Medicine and Human Performance, School of Sport and Education, Brunel University, Middlesex, England.
Undertaking specific exercise training, as an athlete would do in preparation for an Olympic Games, is just as important for a hip replacement patient about to go through surgery or a cancer patient about to undergo chemo or radiotherapy. This activity is often referred to as ‘prehab’ and its aim is to improve the physical condition (fitness) of the patient prior to the upcoming ‘challenge’.
The benefits of being well-conditioned prior to major ‘systemic’ challenges extend widely and include: allowing the individual to cope better with the stress of the local tissue disruption and ‘systemic assault’ (e.g. the consequence of a major operation and use of GA; the use of radio- or chemo- therapy), faster recovery and a better response to rehabilitation, requiring fewer drugs, including pain killers and, through having greater sense of control, reduced anxiety and reduced psychological stress.
In designing appropriate exercise training for prehab there is no ‘one size fits all’ and indeed, the detail of the exercise programme should be customised to the individual. The most important planning considerations in this regard are current impediments to physical activity (PA), recent (last 3 months) PA history and what the event is that the individual is being ‘conditioned’ for.
Most patients are unlikely to be particularly fit (estimated from the fact that only 30% of the total population engage in even the minimum recommended amount of PA) and so any increase in daily physical activity, however modest should be adopted as improvements in fitness will result. The ideal scenario would be the patient who, as a bare minimum, already complies with the UK Department of Health PA guidelines, 2011 (‘Start Active, Stay Active’) and then undertakes a minimum of 12 weeks of more specific exercise training the purpose of which is to prepare the individual to better cope with the anticipated demands of the upcoming procedure. Whatever the individual’s starting point, for all patients the aim should be to improve aerobic power and muscle strength.
Aerobic power is generally often referred to as ‘VO2max’, the amount of oxygen that can be utilised during maximal exercise. As such it represents functional capacity and so, whether it is required for an extreme feat of human physical performance or for simply carrying out everyday tasks, having a ‘good’ VO2max is important. ‘Good’ of course is relative to the, soon to be imposed, demand. So, to run a 4-min mile requires a VO2max above 75 ml·kg-1·min-1 but simply to be functionally independent (an elderly individual living alone for example) requires a VO2max above 15-18 ml·kg-1·min-1 (Peterson et al, 2004). Immediately following coronary bypass, patients can be in the 10-15 ml·kg-1·min-1 range. The normal range for healthy, sedentary individuals is 35-40 ml·kg-1·min-1 for men and 30-35 ml·kg-1·min-1 for women. Although these last two ranges are the ‘norm’ they are not good ‘default settings’ for human beings and we should all be aiming to improve our fitness through being active throughout our entire lifespan and, on a weekly basis, exceed the Department of Health guidelines.
An inverse relationship has been demonstrated between VO2max and all-cause morbidity and mortality (Blair, 1989; Kodama, 2009), in other words the higher your VO2max the lower the risks of disease and death.
Improving fitness, as determined by increasing VO2max, is important as demonstrated by the 10% reduction in health risks with just a 1 ml·kg-1·min-1 increase in VO2max (Cavanagh, 2002, 2003). Hence, very small improvements in aerobic fitness can result in significant decreases in health risk. That is why, for all of us, simply doing a little more PA than we are currently accustomed to can make such a big difference. In addition, work with elite athletes has demonstrated that having a good VO2max also improves the individual’s ability to cope with a large training volume and to recover more quickly after training and competition. For patients, being able to recover faster makes good sense, whilst being able to handle a larger training volume will mean they will get fitter (exercise, like any drug, has a dose-response curve, but the difference with exercise is that, generally, the more training that is done the better the response). This all equals an easier and faster recovery with a better end point; better function, improved well-being and improved quality of life after the event.
Strength training is also important as it will contribute hugely to improved muscle function, the rate of recovery, the effectiveness of repair, better balance and posture control and the return to optimal function following treatment. It is important that strength training address the whole body not just the muscles which will be disrupted. This is because there will be a severe acute reduction in mobility and the impact of this can be lessened with strength training. For example, if the upper body is strong it will facilitate crutch use in the first month following the procedure (hip replacement for example). It will also allow earlier and more effective use of the affected body part.
The tenets of strength training have evolved little since Delorme and Watkins established the ‘3 sets of 10 repetition’ paradigm in the late 1940’s with soldiers, many of them amputees, returning from the Second World War. We now teach students that the most effective strength training programmes are governed by the mantra ‘high weight, low rep’. Hence, a very good programme involves determining, for a given muscle group or movement, the load which can be lifted 10 times before a rest is required. That set of 10 repetitions, with the identified load, is carried out three times with a number of muscle groups in each training session. Strength will of course improve and so the 10 rep max (10RM) should be reassessed every 3-4 weeks and training should continue with the new heavier load. In this way, two of the ‘Training principles’; overload (using a load greater than the individual is currently used to) and progression (regularly increasing the load to maintain the stimulus for continuing adaptation) can be applied.
When it comes to programming exercise training programmes, GP referral can be extremely useful and the fact that this is often funded for 12 weeks may be an excellent way to integrate prehab into everyday life prior to a medical procedure.
Blog moderated by Ann Gates, Founder of Exercise Works!