Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Physical activity and falls
- Gert Jan Wijlhuizen, Marijke Hopman-Rock (22 December 2008)
-
Exercise for those short of 150 minutes a week
- Peter J Bourdillon (15 January 2009)
-
The importance of physical activity measurement
- Thomas Yates, Kamlesh Khunti, Melanie Davies (16 January 2009)
|
|
|||
|
Gert Jan Wijlhuizen, Senior researcher TNO Quality of Life, 2301CE Leiden, The Netherlands, Marijke Hopman-Rock
Send response to journal:
|
In the article the issue is addressed that increased physical activity among the intervention group is associated with increased injury and falls. These results fit into the results of three recently published articles in Preventive Medicine in which we showed that an increase in physical activity was (strongly) associated with falls in older persons. In these articles it is stated that we need to redefine our measure of falls risk by taking the ratio between number of falls (per year) and the level of exposure to falls (physical activity measure). Some theoretical concepts are described to interpret the impact of physical activity on falls. A thesis on this subject will be published on line within two months. References: Wijlhuizen GJ, Chorus AM, Hopman-Rock M. The 24-h distribution of falls and person-hours of physical activity in the home are strongly associated among community-dwelling older persons. Prev Med. 2008 Jun;46(6):605-8. Wijlhuizen GJ, Chorus AM, Hopman-Rock M. Fragility, fear of falling, physical activity and falls among older persons: some theoretical considerations to interpret mediation.Prev Med. 2008 Jun;46(6):612-4. Wijlhuizen GJ, de Jong R, Hopman-Rock M. Older persons afraid of falling reduce physical activity to prevent outdoor falls. Prev Med. 2007 Mar;44(3):260-4. Wijlhuizen GJ. Physical activity and falls in older persons, Development of the Balance Control Difficulty Homeostasis Model. Thesis, Febuary 2009. Competing interests: None declared |
|||
|
|
|||
|
Peter J Bourdillon, Hon. Senior Lecturer ECG Dept, Hammersmith Hospital, London, W12 0HS
Send response to journal:
|
I have difficulty in believing that I'm the only person who thinks that exercising for 30 minutes on 5 days a week is a chore. Instead, I climb to the 7th floor twice a week taking 2 steps at a time, I 'race' others up parallel escalators in London Underground stations and I do 'press-ups' every morning. All of these I do with the express intention of getting out of breath so I know I have stressed my cardiovascular system. Because none of these activities take much more than a minute, I fall into the inactive category. Knowing that only a small proportion of patients advised to exercise continue to do so for any length of time, I decided to start getting patients to exercise in the clinic. The purpose was to show how out of breath I thought each person should be when they exercised at home. The equipment in the clinic room consisted of a pair of steps, a simple frame to stop the steps sliding and a pair of rails to hold onto (see photograph; the door was not in use). The rails were the suggestion of a patient. Patients, aged 18 to 92 and even those in a wheelchair, were invited to walk up and down the steps as fast as they could 20 times. I timed how long they took and stopped them if they were getting more breathless than I thought acceptable. After the patient had recovered his/her breath I recommended that he/she gets out of breath like that every day (or if they were very breathless I would say 'as breathless as you were after going up and down the steps 15 times’). I suggested that if the patient had stairs at home he/she goes up and down the bottom pair of steps 20 times every day holding onto the bannister. Alternatives suggested were daily cycling, jogging, swimming, walking uphill, press-ups and sex. I added that most people find it difficult to get out of breath walking on the flat. Over a 13 month period from 1 September 2003 to 30 September 2004 I saw 156 patients in the Rapid Access Chest Pain Clinic who had both an exercise ECG and went up and down the steps within the space of 2 hours. All but six managed to climb the steps 20 times and the graph compares the metabolic equivalents with the time taken to go up and down the steps. The other six achieved between 1 to 8 METS and climbed between 10 and 18 steps taking between 58 and 123 seconds. The consequences of patients following the advice were: · those with non-anginal chest pain and with atypical angina lost their chest pain within 6 weeks · many with typical angina lost their chest pain within 6 weeks, while the remainder lost about 75% of their pain; as well as being given life- style advice, the patients were advised how to use glyceryl trinitrate and prescribed a statin · those with typical angina could 'turn on-and-off' their pain by stopping and restarting exercising · at 2 months two out of three patients were getting out of breath three or more times a week · those with non-anginal chest pain seen once but re-referred many months later were still exercising 3 or more times a week The benefits of getting patients in the clinic to walk up and down a pair of steps 20 times as fast as possible are: · it shows the doctor what the patient is able to do · it shows the patient what he/she is able to do · it shows the partner or patient’s carer, if present, what the patient is able to do · based on how breathless the patient gets, it enables the doctor to advise the patient as to the amount of exercise he/she should be doing · it is a method for monitoring a patient’s progress · in patients in atrial fibrillation, it gives an idea of how good the control of the heart rate is I submit that a routine that only takes a couple of minutes a day is more attractive to many than having to do something 5 times a week for 30 minutes, and that showing someone how out of breath he/she should get on each occasion is motivating. Competing interests: None declared |
|||
|
|
|||
|
Thomas Yates, Senior Researcher Diabetes Research, Knighton Street Outpatients, Leicester Royal Infirmary, LE1 5WW, Kamlesh Khunti, Melanie Davies
Send response to journal:
|
We read with interest the article by Lawton et al., which described and evaluated an exercise on prescription scheme for women between 40 and 74 years of age in New Zealand. Although the Department of Health’s planned vascular checks programme (1), which aims to evaluate and treat vascular disease risk in all individuals between 40 and 75, makes this study of particular relevance to the United Kingdom, we believe it has several serious limitations which are important to elucidate fully. The study’s primary outcome was change in physical activity, measured by questionnaire, which the authors assure us was validated against heart rate monitors and the International Physical Activity Questionnaire. Self- reported measures of physical activity, including the International Physical Activity Questionnaire (2), have poor validity when compared to objective measures of physical activity, such as accelerometers. In particular, this is because physical activity questionnaires have inherent limitations when measuring habitual forms of light- to moderate-intensity physical activity (3), such as walking, which generally form the majority of physical activity carried out in the general population. Therefore comparing two forms of physical activity questionnaire does nothing to establish validity. Using heart rate monitors as a criterion method to validate physical activity questionnaires also has limitations on account of biological variability (4), which are likely to be compounded at lower exercise intensities. Furthermore, the reference that the authors provide as proof of validation uses a cross-sectional methodology (5); no evidence is provided for the validity and sensitivity of the instrument at measuring physical activity behaviour change. These are serious limitations for a primary outcome. These limitations notwithstanding, the study only found a difference between groups in change in physical activity of 15 minutes per week at 24 months. A difference in physical activity of this magnitude is far below what would be expected to confer health benefits, as supported in this study by the lack of a difference between groups in blood pressure, cholesterol, glycaemic control, fasting insulin, body weight and waist circumference. Even on a population level, a difference in physical activity of this magnitude would be largely insignificant. Therefore the authors’ statement that this study supports the use of exercise on prescription schemes is puzzling - particularly given the fact that one of the few significant findings reported in the study was that the intervention group experienced significantly more falls and injuries. We agree with the authors that developing and evaluating pragmatic approaches to promoting physical activity in primary care is vitally important in light of the increasing prevalence of many chronic diseases, such as type 2 diabetes. However, such studies need to demonstrate efficacy at promoting behaviour change and improving health outcomes using robust techniques before they can inform public health policy. 1. Department of Health. Putting prevention first. Vascular checks: Risk assessment and management.2008, Department of Health, London 2. Craig CL, Marshall AL, Sjöström M, Bauman AE, Booth ML, Ainsworth et al. International physical activity questionnaire: 12-country reliability and validity. Med Sci Sports Exerc 2003; 35: 1381-1395. 3. RJ Shephard: Limits to the measurement of habitual physical activity by questionnaires. Br J Sports Med 2003; 37:197-206, 4. Achten J and Jeukendrup A. Heart rate monitoring: Applications and limitations. Sports Med 2003; 33: 517-38 5. McLean G, Tobias MI. The New Zealand physical activity questionnaires: report on the validation and use of theNZPAQ-LF and NZPAQ- SF self-report physical activity survey instruments.Wellington, New Zealand: Sport and Recreation New Zealand (SPARC), 2004. www.sparc.org.nz/research-policy/research/nzspas-97-01/nzpaq Competing interests: None declared |
|||