Exercise Training Programmes
Although the most effective exercise training programme to improve clinical outcomes requires clarification, the current evidence suggests a number of important prinicples to consider when designing an exercise programme. Firstly the exercise training programme should be derived from objective measured physical fitness ideally using CPET. It should be a supervised, individualized, structured and responsive exercise training programme. To ensure that the training programme is safe, feasible, effective and time efficient it should incorporate the
FITT-VP principle: Frequency, Intensity, Time, Type, Volume and Progression 38 39 40.
Frequency
Describes how many times per day, per week or per month that the exercise training is performed.
The WHO guidelines and the “Start Active, Stay Active” report states that adults >19 years old should complete 150 minutes of moderate intensity exercise per week in sessions of more than 10 minutes duration. However it is suggested that 75 minutes/three sessions a week of vigorous intensity activity can replace the 150 minutes/five sessions of moderate intensity exercise 40 (American College of Sports Medicine 2013; Department of Health, Physical Activity, Health Improvement and Protection 2011). Given that “lack of time” remains as one of the most frequently reported barriers to regular exercise participation flexibility around the frequency and duration is probably important. 41
Intensity
Describes how hard the exercise is per session.
This is thought to be the most important component of the FITT- VP principle as this determines the physiological response to exercise and the mechanism whereby interval training is induces anti-inflammatory mediators. Therefore this form of exercise training may allow the patient to tolerate the metabolic and inflammatory demands of surgery42 43.
The exercise intensity can be derived using objective measures; these include the percentage of oxygen uptake (VO2ml/min or ml/kg/min), % of heart rate/heart rate reserve or using subjective measures using the Borg score or the modified Borg score. Perhaps a combination of both objective and subjective measures could be incorporated in the derivation of the exercise training programme and the monitoring of the response to training. CPET remains the most robust method of deriving and informing the individuals’ response to exercise training; although this method is more time consuming and a relatively expensive 38.
What intensity should we use?
Intensity Domains
Moderate Exercise:
incorporates the range of VO2 in which there is no sustained elevation of arterial lactate concentration i.e. below anaerobic threshold. Performed at 46- 64% of VO2peak or 64-76% maximum heart rate, 12-13 on rated perceived exertion (RPE) or performed at 80% of anaerobic threshold.
Heavy Exercise:
Where there is a sustained increase in arterial blood lactate levels, therefore between anaerobic threshold and maximum VO2 but with the lactate concentration not continuing to increase with time.
Severe Exercise:
Restricted to work rates requiring maximum VO2 at which arterial blood lactate continues to increase throughout exercise.
Severe/vigorous Intensity: 64 to <91% VO2peak, 76 to 96% heart rate max, 14 to 17 RPE.
Time
The duration of the exercise training session in minutes or hours
When designing an exercise training programme, this can be broken down into time spent exercising (e.g. duration of exercise repetition), and time spent recovering (duration of rest period). This is particularly useful during interval training, where the time spent exercising and recovering can vary across trials.
Timing of when the exercise training begins and ends is also important in the neaodjuvant setting. It has been shown that it is safe to exercise train patients immediately after long course chemoradiotherapy for between 6 - 918 44 weeks prior to surgery and recent unpublished data has shown that it is also safe and feasible to start the training programme prior to and continue during and after palliative chemotherapy in patients with advanced lung cancer.
Type
The mode of exercise undertaken (e.g. walking, cycling or treadmill, and strengthen/resistance training or a combination) of both if performed on separate sessions.
Volume
This is the product of frequency, intensity and time, therefore the amount of exercise performed.
Progression
This relates to how the prescription of exercise training advances over the course of the training programme.
As previously stated the exercise training programme should be responsive to an individuals change in fitness levels. This is significantly important when incorporating and exercise training programme concurrent with cancer treatments. It has been previously documented that both chemotherapy and chemoradiotherapy significantly reduces physical fitness levels. Therefore this needs to be taken into account to ensure that the desired exercise intensity is maintained and adhered to throughout the programme. Any element of the training frequency, intensity or time can be adjusted, however it is recommend that only one should be changed at any time.
What type of training programme
Interval training
A type of physical training that involves a series of low- to high-intensity exercise workouts interspersed with rest or relief periods. The high-intensity periods are typically at or close to anaerobic exercise, while the recovery periods involve activity of lower intensity. Varying the intensity of effort exercises the heart muscle, providing a cardiovascular workout, improving aerobic capacity and permitting the person to exercise for longer and/or more intense levels 45. Interval training can refer to organization of any cardiovascular workout (e.g., cycling, running, rowing, etc.), and is prominent in training routines for many sports.
Continuous training
Also known as continuous exercise, is any type of physical training that involves activity without rest intervals. Continuous training can be performed at low, moderate, or high exercise intensities, and is often contrasted with interval training, often called high-intensity interval training 46. Some training regimens, such as Fartlek, combine both continuous and interval approache s47 48 49.
Exercise modes noted as suitable for continuous training include indoor and outdoor cycling, jogging, running, walking, rowing, stair climbing, simulated climbing, Nordic skiing, elliptical training, aerobic riding, aerobic dancing, bench step aerobics, hiking, in-line skating, rope skipping, swimming, and water aerobics.
Strength training/Resistance Training
A type of physical exercise specializing in the use of resistance to induce muscular contraction which builds the strength, anaerobic endurance, and size of skeletal muscles 50 51.
When properly performed, strength training can provide significant functional benefits and improvement in overall health and well-being, including increased bone, muscle, tendon and ligament strength and toughness, improved joint function, reduced potential for injury, increased bone density, increased metabolism, increased fitness, improved cardiac function, and improved lipoprotein lipid profiles, including elevated HDL ("good") cholesterol. Training commonly uses the technique of progressively increasing the force output of the muscle through incremental weight increases and uses a variety of exercises and types of equipment to target specific muscle groups. Strength training is primarily an anaerobic activity, although some proponents have adapted it to provide the benefits of aerobic exercise through circuit training.
It has been shown that interval training is more effective than continuous training 52 53. Therefore exercise training programmes should include moderate and severe/vigorous exercise intensities.
Prehabilitation has been shown to be more effective at improving exercise capacity than rehabilitation, however the benefits of prehabilitation are unlikely to be sustained post surgery 54. The adherence to home-based exercise training has been shown to vary from 15-90%25 55. Community-based data adherence data in other patients cohorts is encouraging 55 and may be the most cost effective setting to deliver exercise treatment in patient undergoing major surgery.
The current data in surgical patients supports supervised, interval training that may be initiated during or after cancer treatments. To date unsupervised training at home has not been as effective as supervised training in either a hospital or community setting. Further clinical trials are needed and it is currently unclear what the optimal supervision, location, timing or duration of training is for surgical patients.
