ROLE OF HEREDITY AND ENVIRONMENT IN SPORTS

1. TOPIC: ROLE OF HEREDITY AND ENVIRONMENT IN SPORTS
Presented by : Punam Pradhan

2. ROLE OF HEREDITY AND
ENVIRONMENT IN SPORTS

3. WHAT MAKES YOU
WHO YOU ARE??

4. GENES
GENETICS
(Study of
Heredity)
HEREDITY is the passing on of traits from parents
to their offspring

5. How are traits passed on?
• When organism reproduce.
• Traits are carried in DNA,
the genetic material found
in cells nucleus.
• DNA acts like a blue print
to create characteristics.
• A section of DNA
responsible for a specific
trait is known as ALLELE-
different forms of
characteristics.

6. GENES
• Genes are chromosomes,
Molecules of DNA- DNA
consists of 46 chromosomes
arranged in 23 pairs.
• GENES control biological
traits:
 Found on the chromosomes
in every cell of the body.
Characteristics come from a
combination of both parents.
Half of your chromosomes
come from your mother,
half from your father.

7.  Heredity is responsible for all the physical traits, the instincts
inborn traits, emotions, I.Q., and reflex action.
Notice that the puppies have physical traits of both parents – Heredity at work
 Animals not only inherit physical traits, they also inherit
behaviours from their parents. The animal is born knowing
thus , it does not have to learn.
 For a new born (in human beings) to learn to stand and walk
it takes months or years in an environment where they are
encouraged.
 It is the environment that determines what we learn.

8. ENVIRONMENT
• Environment includes all things , living and non
living, that surround an organism.
• Environment is responsible for the growth &
development of the physical, mental and social
traits

9. IS IT SO THAT WE INHERIT ONLY
FROM OUR PARENTS.
WHAT’S YOUR TAKE ON THIS?

12. LAWS OF HEREDITY
• LIKE PRODUCES LIKE
Law 1
• ONLY CERTAIN TRAITS ARE
TARNSFORMED
Law 2
• CONVERGENCE OF TWO LIVES
Law 3

13. • Galton in his pioneer work on Hereditary Genius (1869) has
sought to show that the probability of the occurrence of greatly
gifted children is vastly higher when the fathers are of a superior
intelligence.
• Karl Pearson had given evidence to show that for people of the
same race within a given community, heredity is more than seven
times more important than environment.
• No person can be born without heredity and genes cannot
develop without proper environment. Each trait and response of
an individual depends on his heredity and environment.
ROLE OF HEREDITY IN SPORTS

14. • ATHLETIC PERFORMANCE is a complex trait that is influenced
by both genetic and environmental factors.
• Many physical traits helps to determine an individual’s
athletic ability, primarily the strength of muscles used for
movement and the predominant type of fibers that compose
them.
• Skeletal muscles are made up of two types of muscle
fibers (Slow twitch & fast twitch).
• Other traits related to athleticism include maximum amount
of oxygen the body can deliver to its tissues (aerobic
capacity), muscle mass, height, flexibility, coordination,
intellectual ability, and personality.

15. • ACTN3 and ACE genes influence the fiber type that makes up
muscles, and they have been linked to strength and
endurance.
• The ACTN3 gene provides instructions for making a protein
called alpha (α)-actinin-3, which is predominantly found in
fast-twitch muscle fibers.

16. • A variant in this gene, called R577X, leads to production
of an abnormally short α-actinin-3 protein that is quickly
broken down.
• Some people have this variant in both copies of the gene;
this genetic pattern (genotype) is referred to as 577XX.
These individuals have a complete absence of α-actinin-3,
which appears to reduce the proportion of fast-twitch
muscle fibers and increase the proportion of slow-twitch
fibers in the body.

17. • Some studies have found that the 577XX genotype is more
common among high-performing endurance athletes (for
example, cyclists and long-distance runners) than in the
general population, while other studies have not supported
these findings.
• The 577RR genotype is associated with a high proportion of
fast-twitch fibers and is seen more commonly in athletes
who rely on strength or speed, such as short-distance
runners.

18. ENVIRONMENT & ITS ROLE IN SPORTS
• The environment is in charge of the development
of physical, mental, and social characteristics.
• Genes cannot grow in the absence of an appropriate
environment.
• According to P Gisbert, “Environment is anything
immediately surrounding an object and exerting a direct
influence on it”
• According to Field and wield , “A persons environment
consists of the sum total of the stimulation which he
receives from his conception until his death”

19. Environment is classified into 2 categories:
I. Internal environment
II. External environment
External environment is further classified into:
I. Physical environment (Climate, weather, geographical
location etc.)
II. Social environment (Society, Family, peer group, teachers
etc. )

20. ROLE OF PHYSICAL ENVIRONMENT IN
SPORTS
 It affects physical growth and gene development of a potential
sports talent.
 Inappropriate physical environment leads to a negative effect
on physical growth which further compromises sports
performance at highest level.
 In high altitude environment, Endurance sport performance is
strongly benefited by an increased ability to carry and
transport oxygen around the body to the working muscles.

21.  Training in excessive temperature
leads to heat edema, heat rash, heat
syncope, heat cramps, heat
exhaustion and heat stroke which
leads to loss of performance and in
severe conditions even life of an
athlete.
 A person living in mountains will have
shorter average height as compared to
an individual living in plane areas.

22. ROLE OF SOCIAL ENVIRONMENT IN
SPORTS
 Socioeconomic status is directly related to
sports performance, because if the basic &
advanced necessities of an athlete remains
void then he is on high ranks to underperform.
 Insufficient nutrition will affect growth,
development and recovery of a sportsperson.
 Family & social support enhances willingness
of an athlete to achieve his/her goal.
(example: The way athletes are supported by
family and their society is remarkable)

23.  A constructive social environment will have high probability
for significant performance, whereas a destructive society
will have detrimental effect.
 Peer group has a strong influence on an athlete and it can go
either way to equate sporting talent development and
performance.
• Social environment has influence on mental ability, thought
process, behavior, personality and these factor determines
outcome of sports development and performance.

24. ROLE OF TRAINING & NUTRITION
IN SPORTS
• Training is the predominant demand in the
athletic lifestyle.
• It is characterized by acute bouts of high power
output.
• During one hour of hard training an athlete may
expend 30% of his or her total 24-hour energy
output.
• These high power outputs have important
implications for energy substrate and water
requirements.

25. • Carbohydrate, specifically muscle glycogen, is
an obligatory fuel for the high power outputs
demanded by athletic sports.
• Muscle glycogen is a limiting factor in hard
exercise because it is held in limited amounts,
utilized rapidly by intense exercise, and
fatigue occurs when it is depleted to low
levels in the active muscles.
• Liver glycogen may also be exhausted by
hard exercise and low blood glucose
contributes to fatigue.

26. • High sweat rates are demanded during severe
exercise and large water deficits
commensurate with energy expenditure are
incurred during extended periods of hard
training and competition.
• Salt, potassium, and magnesium are lost in
nutritionally significant amounts in the
sweat, but vitamins and trace elements are
not.
• Adaptive mechanisms protect athletes
against electrolyte depletion. Iron loss in
sweat may contribute to the iron deficiency
seen in some endurance runners.

27. • Protein is degraded and amino acids are
oxidised during physical exercise.
• Protein is also retained during muscle
building training.
• Recent investigations indicate that the
minimal protein requirements of athletes
may be substantially higher than those for
sedentary persons.
• Nonetheless, all the protein that athletes
need will be supplied by a conventional diet
and protein supplements are not required.

28. • Liberal carbohydrate and water consumption
is essential for full recovery between training
sessions and in preparation for competition.
• The pre-competition meal provides limited
benefits other than promoting full hydration.
• Large intakes of simple carbohydrates close to
competition may precipitate hypoglycaemia
and impair performance.
• During exercise, water consumption to replace
sweat losses is the major concern.

29. • Genetics is the science of heredity and variation
in living organisms.
• Physical fitness has also a strong genetic
component, up to 50%
• The physical performance phenotypes for which a
genetic basis can be suspected include
endurance capacity, muscle performance,
determinants of tendon–ligament apparatus and
physiological attitude to train.

30. MUSCLE PERFORMAMNCE
• Heterogeneity is a property of all muscles and
seems essential for their function.
• Combination of histochemical ATPase staining,
antibody staining and electrophoresis has led
to recognize that four major fibre types exist
in skeletal muscles: Slow contracting form
(fibre type I) and Fast contracting forms (fibre
types IIA, IIB and IIX).
• heterogeneity covers all possible aspects of
muscle contractile function

31. • The endurance capacity has been related to a
predominance of ST fibres (.50%), whereas FT
fibres are related to power and speed capacity.
• common genetic variation, which separates
endurance athletes from sprinters, is probably
due to natural selection. The actin-binding
protein [alpha]-actinin-3 (ACTN3) is a highly
conserved component of the contractile
machinery in fast skeletal muscle fibres.
• This protein is only found in FT muscle fibres and
it is responsible for the power necessary for
successful sprinters or track cyclists. ACTN3 is
nearly always present among elite power
athletes,

32. • the R577X polymorphism (premature stop codon
polymorphism) associated with complete ACTN3
deficiency is more prevalent among elite
endurance athletes, such as marathon runners
and rowers.
• Myosin light chain kinase (MLCK), a calcium-
calmodulin-dependent multi-functional enzyme,
plays a critical role in the regulation of smooth
muscle contraction.
• Polymorphisms in this gene, especially the
C37885A allele, are associated with post-exercise
strength loss. Heterozygotes for this
polymorphism also demonstrate greater strength
loss compared with the homozygous wild type
(CC).

33. • the gene encoding angiotensin-converting enzyme
(ACE). The ACE gene has two alleles, termed ‘I’ and ‘D’;
the deletion (D) allele of the human ACE gene is
associated with higher ACE activity than the insertion
(I) allele in both tissue32 and serum.
• Some evidences that genetic variation in the ACE gene
might be Genetics and associated with many heritable
traits, including physical, physiological, skill parameters
and physical performance.
• An increased frequency of the ACE I allele has been
observed in elite endurance athletes.
• An increased frequency of the ACE D allele has been
associated with elite sprint performance.
• The insulin-like growth factor 1 protein (IGF-1)
increases muscle mass and possibly strength.

34. OVERVIEW OF THE GENETICS OF
ATHLETIC PERFORMANCE
• Genetic factors undoubtedly contribute to
athletic performance.
• Idea of predicting future athletic success
through genetic testing in children is becoming
increasingly common.
• Every sport has unique physical requirements
and these requirements vary between sports.
• Athletic performance is one of the most
complex human traits.
• Body morphology, endurance, strength, and
power are primary factors underlying athletic
performance.

35. • Aerobic endurance is the ability to sustain
an aerobic effort over time. (e.g distance
running or cycling)
• Muscle power is the interaction between the
force and velocity of a muscle contraction
(e.g. an explosive movement such as vertical
jump).
• Elite athletic status, results from the
interaction of a combination of genetically
driven physical and mental traits with the
ideal environment for athletic success.

36. HERITABILITY OF SUB-TRAITS
• Heritability of a trait is generally considered an
estimation of the importance of genetic factors to
that trait.
• Heritability of athletic status (regardless of sport) is
estimated to be 66% .
• Height, which is critical for success in some sports, is
highly heritable, with about 80% of the variation
due to genetic factors .
• Body type (having mesomorphic or ectomorphic
somatotype) is also highly heritable. Somatotypes
are classically associated with power or endurance
athlete status.

37. • osta et al. reviewed the existing family and
twin studies related to specific endurance
and muscular strength phenotypes.
• Aerobic endurance, as reflected by
VO2max has a heritability of about 50% .
• Heritability estimates for muscular strength,
and power range from 30 to 83%,
depending on the specific muscle and type
of contraction.

38. GENES
• Specific genes and sequence variants
(polymorphisms) within genes have been
associated with performance.
• The angiotensin-1 converting enzyme
insertion/deletion (ACE I/D) polymorphism,
and the α-actinin-3 (ACTN3) R577X
polymorphism, both of which have been
examined in several populations using a
variety of experimental approaches.

39. ACE I/D
• ACE gene codes for angiotensin-1 converting
enzyme, part of the renin-angiotensin system
responsible for controlling blood pressure by
regulating body fluid levels.
• The ACE gene has two alleles, termed ‘I’ and
‘D’; the deletion (D) allele and the insertion (I)
allele
• ACE I allele represents a 287 bp insertion and
is associated with lower serum and tissue ACE
activity(endurance performance and higher
exercise efficiency )
• The D (deleted) allele is associated with higher
serum and tissue ACE activity( strength and
power performance)

40. ACTN3 R577X
• ACTN3 gene codes for the protein α-actinin-3, a
structural sarcomeric protein found in the fast type II
muscle fibers.
• A polymorphism leads to a premature stop codon (X)
rather than an arginine (R) at position 577.
• The R allele (related to power-oriented events), as the
RR genotype is overrepresented in elite power athletes,
while the XX genotype is associated with lower sprinting
ability and muscle strength.
• Power athletes were approximately 50% less likely to
have the XX genotype and endurance athletes were
approximately 1.88 times more likely to have the XX
genotype vs. the RR genotype.

41. KEY POINTS
• Athlete status as well as many cardiovascular
endurance and muscular phenotypes are highly
heritable, supporting a role for genetic factors
in the achievement of athletic success.
• The ACE I/I genotype is consistently associated
with endurance performance.
• The ACTN3 R/R genotype is consistently
associated with power-oriented performance.