Activity and exercise come in many different forms, but my number one favourite is walking. This is at least partly based on the fact that walking is something almost everyone can do, and doesn’t require any special skills or for someone to be ‘sporty’. Another reason for my enthusiasm for walking is that fact that it can be really very good exercise indeed, and is associated with a range of benefits for both health and wellbeing.
For some, walking is an activity that they can incorporate into their daily lives without too much upheaval, which increases the chances that the activity will be sustainable in the long term. Plus, there have been a few studies now that suggest that more frequent bouts of activity of shorter duration are, generally speaking, as beneficial to health as longer bouts of activity. This is very good news, I think, for individuals who don’t feel they have the time to carve out 30-40 minutes of continuous walking, and find it easier to get their activity in bursts lasting, say, 5-15 minutes.
With this in mind, I was interested to read a study published in this month’s edition of the American Journal of Clinical Nutrition. The study tested the effects of walking on individuals’ responses to a meal consisting of bread, cheese, mayonnaise, potato crisps and milkshake. The individuals in this study were each tested with 3 different regimes:
1. A day of rest, followed the next day by assessment after two test meals (this regime acted as the ‘control’)
2. One 30-minute bout of brisk walking on one day, followed the next day by assessment after the test meal
3. Ten, 3-minute bouts of brisk walking on one day, followed the next day by assessment after the test meal
One assessment that the individuals underwent was measurement of blood fat levels known as triglycerides (TG) after the meals. Higher TG levels are associated with an increased risk of cardiovascular disease. Walking was associated with a significantly reduced TG level after eating the following day compared to the control regime. Also, both walking regimes were found to be equally beneficial with respect to this.
Walking was also found to reduce systolic blood pressure (the higher of the two blood pressure values). Again, the two walking regimes were equally effective here, giving a reduction of about 7-8 points (mmHg).
In the discussion of this paper, the authors write: “Our findings provide evidence that health benefits arise after the accumulation of moderate intensity physical activity in short bouts, at least for postprandial triacylglycerol concentration and resting blood pressure. Such changes suggest (but do not prove) that CVD [cardiovascular disease] risk may be reduced in persons whose physical activity patterns are characterized by the accumulation of short bouts of physical activity throughout the course of each day. Such an activity pattern may be attractive for persons who want to improve their health through the accumulation of routine physical chores or pastimes because these activities are intermittent in nature and often involve bouts lasting <10 min.” Basically, these results are further good news for those individuals who prefer to or find it easier to get their exercise in short bursts throughout the day rather than in one big chunk.
References:
Miyashita M, et al. Accumulating short bouts of brisk walking reduces postprandial plasma triacylglycerol concentrations and resting blood pressure in healthy young men. Am J Clin Nutr 2008;88(5):1225-31
Dr Briffa,
Firstly thanks for continuing flow of interesting blog entries, most of which question ithe existing orthodox views.
My take on this “research” is:
(i) Some activity is better than none.
(ii) If triglycerides are a inditor of CVD risk, cutting carbohydrate intake and following a low carb diet would be far more beneficial.
There seems to be a never ending debate about how much or little exercise is beneficial froma health perspective. I guess it depends on numerous factors, but particularly how active an individual is. If you ahve a sedentary occupation, then you probably need to find room for “exercise”. Similarly if you commute to work by car. If you have an physically demanding occupation you probably get plenty of exercise going about your every day business.
With regard to exercise, type, duration, intensity, etc are all factors which receive dabate. I personally believe everybody should include tasks which maintain or better still develop their endurance, strength and flexibility. Something like yoga, weights and some form of aeobic activity on a daily basis. gardening, walking, housework, commuting, etc can all contribute.
But I personally believe that first and foremost you want to get your diet right. Avoiding processed foods, complex carbs and sugars, and getting plenty of good quality fats, protein and certainly have more of an impact on triglyceride levels and systolic blood pressure than even a prodigous amount of exercise.
It would probaly result in the need to take less prescribed drugs as well.
Paul Anderson.