Healthy Walking in your Lunch Hour – Optimising healthy walking
activity over 30 minutes


Sukin Reddy

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MBBS, MS Ortho




submitted in part fulfilment of the

MCh Orthopaedics

University of Dundee

April ~ 2018

CHAPTER 1              


Maintaining an active lifestyle has become challenging
these days. Work demands in particular are getting in the way of exercising.
While we struggle to find time to exercise, we cannot afford to forsake
exercise because it is integral to sustained healthy success and a well-rounded
life. Physical inactivity is now estimated to be one of the leading causes of
death worldwide (World Health Organization,
2010). Prolonged sedentary behaviour can have dangerous
health consequences, including increased risk of diabetes, cardiovascular
disease and premature mortality (Hill et al, 2015).

There is emerging evidence IC1 to
suggest that participation in light intensity physical activities (e.g.
standing or slow walking) may have benefits for cardio-metabolic health (Hill et al, 2015).

Active travel (walking, cycling and public transport
use) is being promoted as an important component of strategies to increase
physical activity levels internationally (World Health Organization,

Walking is considered as one of the safest, simplest
and most efficient forms of cardiovascular exercise and can be performed almost
anywhere. It is as effective as other forms of cardiovascular exercise and does
not require expensive equipment or regular visits to a gym (Siegel et al, 1995). Walking is a great
exercise for all ages and in some
cases, it can be more effective than
running however a good walking technique is very important to maximise the
results. Walking, as opposed to running, is an
exceptionally safe activity, since it involves having one leg always in contact
with the ground, which minimizes the risk of falls and injuries (Perry and Burnfield, 2010), (Hardman and Morris, 1998).

In 2006, the World Health Organization (WHO) concluded
that walking is the basic form of physical activity necessary for maintaining
good health and should be an inseparable part of a healthy everyday lifestyle,
including working days (World Health Organization,
The recommended amount of exercise for adults is 150 minutes of moderate
physical activity per week. That breaks down to 30 minutes of exercise over
five days a week (World Health Organization,
The American Heart Association
Recommended the same in 2015 and updated them in 2017 (American
Heart Association, 2017).

Although many techniques have been proposed to increase
the efficiency of walking over shorter duration of exercise such as the use of
weights, brisk walking, uphill walking and so on, there is no significant
emphasis on shortening of stride length to improve the intensity of
cardiovascular exercise. Shorter strides while walking increase the step count
and may increase cardiovascular exercise over a 30-minute period compared to
normal/regular strides. There is not a similar study in the available literature
which has evaluated the effects of shorter strides during walking on
cardiovascular exercise. Hence, the reason for conducting this current study in
comparing the outcome.

The study included 50 subjects who normally walk for
thirty minutes or more each day. They will be subjected to a single 90-minute
session comprising two 30-minute walking and one 30-minute rest phase in
between where data will be collected. There will be no follow up and the data
will be analysed after the sample size has been reached.

Previous studies have indicated that slower walking
speed in elderly subjects may be associated with decreased joint movements and
joint kinetics (Kerrigan et al, 2000), (Kerrigan et al, 2001) biomechanical changes (DeVita and Hortobagyi,
and in choosing “cautious” gait strategy (Winter et al, 1990).

Treadmill walking, in theory, is mechanically
equivalent to over ground walking (Savelberg et al, 1998), (Schenau, 1980). In reality,
however, walking on a treadmill can initially be an unfamiliar experience (Schenau, 1980), (Taylor et al, 1996)

Unimpaired younger adults required 4–6?min to
familiarize themselves with the treadmill (Taylor et al, 1996), (Matsas et al, 2000). However, complete
familiarization with a treadmill even in a 15-min single session was not
attained in many elderly adults (Wass et al, 2005).

Therefore, in this current study the normal walking
speed on the treadmill will be defined according to preference of individual


Aims & objectives


To determine whether the use of a stride restrictor
while walking alters cardio vascular exercise.

To study the effect of stride changes on heart rate
and maximal oxygen consumption.


To determine whether a change in stride length can alter
cardiovascular exercise over a 30-minute period.



CHAPTER 2              


Of all types of physical activity, walking stands out
as the most popular form of leisure time exercise (Ham et al, 2009), and can be easily performed
at moderate intensity (Murtagh et al, 2002).

Various studies have been conducted to understand the
benefits of walking as a cardiovascular exercise. Although it has been proved
to be safer and as effective as any other form cardiovascular exercise. Many
research projects have proposed ways of maximising the efficiency of walking to
achieve the same results with a shorter duration of exercise.

Physical activity and aerobic fitness

Noakes IC2 et al. (2009), found that cardio respiratory fitness is more a function of the
intensity of physical activity than its volume in middle-aged women in a study
of 275 women (40.1+/-3.0 years) (Noakes, 2009).

et al. (2013), identified that an increased physical activity level over
a one year period resulted in increased aerobic fitness in severely obese
subjects. Although the sample size was small (21 subjects, mean age 42), these
results suggest that change in 6-minute walking test may not be a good
indicator of maximal change in aerobic fitness in this population (Adland et al, 2013).

Laudani et al. (2013), conducted a study that included
72 volunteers and concluded that there is a significant association between physical
activity levels and physiological determinants of mobility in young,
middle-aged and older individuals living in a city district, with significant
differences in the relative role played by volume and intensity of overall physical
activity and selected habitual activities. While aerobic function was
associated to the volume of activity, neuromuscular function and functional
abilities showed a significant association exclusively with the intensity of
physical activity (Ludini et al, 2013).

Physical activity and Disability

Nusselder et al. (2008), identified that performing moderate
to high levels of non-occupational physical activity reduced incidence, and
showed a higher gain in disability-free years (male 4.1; female 4.7), also a
similar reduction in years with disability (Nusselder et al, 2008).

Physical activity and work

Naughton et al. (2010), conducted a survey in 2010 in
which 44 employees from a health provider (Health) and 63 employees from a
public-sector organisation (PSO) underwent a self-completed questionnaire
enquiring about a broad range of workplace-based exercise issues and identified
that overall, employees from Health and PSO were positive about the policies at
work to encourage exercise but further work was required to
ensure that public health guidance was aimed at improving exercise at work so
that it has maximal worker benefit (Naughton et al, 2010).

McKay et al. (2015), conducted a cross sectional study
of 2,122 adults aged 18 years and above in rural India and Bangladesh and found
that those that achieved the recommended weekly physical activity levels
through work-based activity were more likely to achieve it. The only problem in
this study according to the author was physical activity data were based on
self-reporting similar to the International Physical Activity Questionnaire
(IPAQ), which has been associated with overestimation of physical activity
levels (McKay et al, 2015).

Effect of environmrnt

Handy et al. (2002), published an evidence based study
that was aimed at understanding the interrelationship between the built
environment and human behaviour and then to develop models that predicted the
environmental conditions under which humans will be more physically active.

The study identified that walking and cycling have been
more popular and successful modes of exercise than other forms of travel because
they are relatively easy for the vast majority of the population and offer
relatively little risk of injury.

It was concluded that that a combination of urban
design, land use patterns, and transportation systems that promote walking and cycling
will help create active, healthier, and more liveable IC3 communities (Handy et al, 2002).

Brownson et al.
(2005), identified that
it was difficult to precisely quantify IC4 owing to the lack of long-term data, a
combination of characteristics of the built environment and increases in the
proportion of the population engaging in sedentary activities that put the
majority of the American population at high risk of physical inactivity.

The study
concluded that a complex interaction of cultural, social, economic, and
familial issues has likely set the stage for these changing physical activity
trends (Brownson et al, 2005).

Active travel

Mytton et al. (2017), conducted a study involving 7689
working men in the UK to understand the associations of active commuting with
body fat and visceral adipose tissue and identified that walking and cycling to
work was associated with reduced adiposity relative to exclusive car-use (Mytton et al, 2017).

Walking Training

Kocur et al. (2012), conducted an evidence based study
and recommended parameters of walking training which can be applied to primary
and secondary cardiac prevention (Kocur et al, 2012).

Table 2.1: Kocur et al, parameters of
walking training which can be applied to primary and secondary cardiac


Atalay & Cavlak (2012), studied the impact of
unsupervised regular walking on health in a sample of 40 Turkish middle-aged
and older adults with a mean age of 56.30 ± 4.85 years (range 40–70) walking
for at least 1 year, at least three times a week, and at least 45 min a day and
40 inactive participants with a mean age of 55.15 ± 5.64 years (range 40–70) and
concluded that unsupervised regular walking improves health and is also a safe,
cheap, and can easily be adapted into daily life. Therefore, it can be
recommended to improve physical and cognitive functioning, emotional status,
and quality of life of middle-aged and older adults (Atalay and Cavlak, 2012).

Rosa et al. (2015), conducted a study involving 94
volunteers aged 18+ and found that differences in prior expectations that motivate
people to participate in a training program can augment or reduce the chances
of completing the exercise protocol as 73
volunteers (77.6% of the entire sample – 40 women) did not complete the
protocol, and 21 volunteers (13 women) completed the full 1-year exercise protocol.

The expectation of social interaction was a positive
factor in predicting maintenance of an exercise program and suggested that
structuring physical exercise sessions would facilitate socialization and may
increase adherence (Rosa et al, 2018).

Duration of walk

Harvey et al. (2017), observed in 10 healthy volunteers
that 30?minutes of moderate intensity physical activity can be accumulated in
continuous bouts of at least 10?minutes but it was shown by use of activity monitoring
that it was difficult to achieve 10?minutes of completely uninterrupted walking
in the free-living urban environment where there are obstacles. Oxygen uptake (VO2)
was measured using a gas analysis system.

The study concluded that 10?second interruptions in
walking had no significant effect on the VO2 kg min?1.
However, two breaks of 50?seconds or 100?seconds introduced into a 5-minute
brisk walk showed a significant reduction in oxygen uptake requirements and
metabolic equivalent of task (MET) (p?