BPK 143 Chapter Notes - Chapter 1: Physical Fitness, Motor Coordination, Relative Risk
SchoolSimon Fraser University
DepartmentBiomedical Physio & Kines
Course CodeBPK 143
Genome – all the inheritable traits of an organism
The genotype describes the genetic constitution of an individual.
In contrast, the phenotype of an individual organism describes one of its measurable traits or
characteristics. (like eye colour or aggressive behavior)
Though many phenotypes are a result of genes, some are also significantly affected by
environmental factors (like language).
The interaction between genotype and phenotype can be conceptualized by the following
Genotype + Environment = Phenotype
Fitness level is a phenotype that is influenced by both an individual’s genetics and his or her
Some perspective on fitness:
- basic anatomy and physiology has been pretty much the same over the past 40,000 years
- it’s very different as a consequence of different environments, with our current environment
being predominantly sedentary (accustomed to rest/to take little exercise). This environment
results in abnormal gene expression which results in diseases like hypertension and diabetes.
Current scientific evidence supports the notion that disruptions in cellular homeostasis are
diminished in magnitude in physically active individuals due to the natural selection of gene
expression that supports the physically active lifestyle of our ancestors.
Basically, people who are physically active are healthier and have greater cellular homeostasis
because of natural selection (since our ancestors were physically active cause of hunting and stuff).
In a way, we’re “programmed” to be active, and therefore less active individuals are more prone to
< Don’t blame health problems on genes >
Besides your environment, epigenetics also affect your phenotype. Epigenetics is the study of
heritable changes in phenotype caused by mechanisms other than changes in DNA. Genes can get
“turned on” and “turned off” by the environment humans encounter and this can be passed onto
future generations. Partially heritable biological changes affecting phenotype. You’re phenotype
isn’t completely affected by your parents genes, but are still affected partially. ~EPIGENETICS~
Also diet. Foods available to your ancestors would have been affected by their geographical
location and exposure to these food would have caused some epigenetic adaptation.
“So if we feed an Inuit population and a European population a diet based on lots of grains, the incidence
of type 2 diabetes will be higher in the Inuit population because this is a “newer” food to them. This is
despite the fact that the genome of Inuit and Europeans is essentially the same.” ~EPIGENETICS~
Though the genome is the same between individuals, this does not mean they work in the same
We ain’t adapting to sedentary lifestyles though. Not adapting to being lazier than our past
Physical fitness is the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and
with ample energy to enjoy leisure time pursuits and to meet unforeseen emergencies.
Fitness professionals and academics generally agree on the following components of physical
Cardiorespiratory (aerobic) endurance
Both “health” related and “performance” related are both important to being fit.
Balancing stiffness on all sides of the spine is more critical to ensuring stability than having high forces
on a single side. AKA if you’re gonna boost your abs, work on your back muscles too. MUSCLE BALANCE.
Exercises that include a coordination component can improve strength, endurance, and coordination in
the same amount of time as a simple strength/endurance exercise on a machine.
Tai-chi helps reduce falling among seniors (SO THAAAAT’S WHY)
Motor coordination and balance, incorporated into functional exercises, are very important health
components of fitness. (Prevents back injuries and falling, respectively)
You do not have to be an athlete working out six days a week to benefit from physical activity. Research
shows that a considerable reduction in the relative risk of death can be obtained from only a few
moderate exercise sessions per month. However, fitness experts usually recommend that 3-5 times per
week is optimal.
Strength and flexibility can help prevent back pain and other injuries.
Weight-lifting and an appropriate amount of weight-bearing exercise such as running can help prevent
osteoporosis (fragile bones). And the list goes on.
You can do exercise in short periods throughout the day, like three 10-min walks and a 10min situp and
push-up session. You do NOT need to set aside 30+ mins in one go. Because people think that they
need 1 hour of free time to exercise, they often don’t bother at all.
Exercise stress that is excessively high can reduce the effectiveness of the body’s immune system.
This evidence may explain why extremely high levels of fitness are not required for optimal health and,
in certain circumstances, may actually be detrimental to your health. Individual responses to exercise
are varied; some individuals can tolerate very high levels of exercise stress without adverse effects.
Epidemiological studies - compare the health of populations as they present themselves without any
The studies should have these criteria to be reliable (or at least to the best of its ability):
1. The association between exercise and health must be repeatable (reliable), aka many studies
should have the same result