fatigue and recovery

Download Report

Transcript fatigue and recovery

FATIGUE
AND
RECOVERY
Key Skills and Knowledge


At the completion of this topic, students should have
knowledge of passive and active recovery methods to
assist in returning the body to pre-exercise levels.
At the completion of this topic, students should be able
to:



Explain the role the energy systems play in enabling activities
to occur as well as their contribution to active and passive
recovery.
Explain the multi-factorial mechanisms associated with fatigue
during physical activity and sporting events results from the
use of the three energy systems under varying conditions.
Compare and contrast suitable recovery strategies used to
counteract fatigue and promote optimal performance levels.
(VCE Study Design, 2010).
Fatigue

Chapter 6: Nelson textbook.
 Onset and rate of fatigue varies depending on:
Type of activity
Muscle fibres being used
Types of muscle contractions
Intensity and duration of activity (faster onset
with high intensity)
Fitness level.
Fatigue

Local fatigue- localised, related to a specific
activity, eg. H++ accumulation, soreness from
lunges (DOM’s).
 General fatigue- Physical and mental. Related
to the whole training session; ie. Drained
feeling.
 Long-term (chronic) fatigue- related to
physiological and psychological stress caused
by exhaustion and overtraining. Tired and will
notice a deterioration in performance.
Causes of Fatigue








No single process is responsible.
Due to changes in the internal conditions
within the muscle such as:
Depletion of fuels (ie. Glycogen and CP).
Depletion of high energy P compounds.
Increased body temperature
Dehydration
Changes in blood flow distribution.
Altered level of metabolic by-products such as
ADP.
Fuel Depletion

High Intensity Short
Duration activities
such as pole vault,
rely on PC to fuel the
ATP PC system.
When PC stores
deplete (10 seconds)
the LA energy
system takes over.
This ES is less
powerful.
PC depletion
↓
Increase in inorganic
phosphate
↓
Must decrease
intensity when PC
depleted >95% MHR
PC Depletion
Depletion of energy stores is a primary
factor with fatigue.
 Once ATP-PC system is exhausted,
body uses glycogen as an energy source
(stored in muscles).
 Less oxygen available to working
muscles.

Restoration Rates
Recovery Time
(seconds)
30
Muscle Phosphagen
restored
50%
60
75%
90
93%
120
95%
150
97%
180
98%
10 minutes
100%
AEROBIC VS ANAEROBIC GLYCOLYSIS
AEROBIC GLYCOLYSIS
↓
GLYCOGEN
↓
GLUCOSE
↓
PYRUVIC ACID
SUFFICIENT OXYGEN
↓
CO2 + H20 + ATP
ANAEROBIC GLYCOLYSIS
↓
GLYCOGEN
↓
GLUCOSE
↓
PYRUVIC ACID
INSUFFICIENT OXYGEN
↓
L.ACID + H IONS +ATP
Recovery

Chapter 12 in Nelson, p. 285.
 During recovery the body overcompensates
for the stress placed on it and adaptations
result.
 The principle of recovery states:
 “in order to maximise performance and fitness
benefits, an athlete must recover adequately
from one training stimulus before the next
stimulus is introduced” (Nelson, 2008).
Recovery
All athletes need different recovery
strategies.
 Determined by: type of training
undertaken; intensity and duration.

Recovery Strategies







As part of training session: passive and/or active
recovery and stretching.
Replenishment of fuels (carbohydrates)
Replenishment of fluids + electrolytes.
Hydrotherapy: cryotherapy, ice baths, pools sessions.
Massage
Hyperbaric Chamber- 100% pure O2, more to fatigued
muscles to increase recovery rate.
Psychological Techniques: eg. Progressive Muscle
Relaxation (PMR), Meditation, breathing techniques,
mental imagery.
Cool Down

Passive rest- replenishes CP stores most
rapidly.
 Stretching- to prevent DOMS, PNF and static
stretching as part of cool down whilst muscles
are warm.
 Active recovery- removes lactate. Min. 5-1mins low intensity exercise (<70%hr max) to
maintain high O2 levels required to breakdown
lactate. Prevents venous pooling.
Hydrotherapy

Hot-Cold Showers- vasoconstriction (cold) and
vasodilation (hot) causes a shunting effect in
the blood vessels which speeds up removal of
metabolites.
 Pool sessions: usually next day as recovery
session due to reduced stress of weight
bearing on joints.
 Cryotherapy- immersion in cold water such as
ice bath. Reduces swelling caused by soft
tissue damage. Eg. High collision sports and
where repetitive action causes muscle micro
trauma.
Massage
Stimulates increased blood flow which:
 Increases O2 delivery to muscles,
increases removal of metabilites.
 Relaxes muscles and reduces muscle
tightness improving joint movement.
 Breaks down scar tissue assisting with
muscle repair.
 Relieves swelling.

Progressive Muscle Relaxation
Tensing and relaxing muscles enabling
athlete to understand the difference
between tensing and relaxing muscles.
 E.g. isolate one muscle group, create
tension for 8-10 seconds then let the
muscle relax and the tension go.
 Develops skills for releasing tension,
resulting in decreased muscle tension.

Meditation
Relaxing by controlling the CNS and
reducing the number of cues to the brain.
 Less stimulation results in lower blood
pressure and HR, slower breathing and
relaxed muscles.

Other: Compression Clothing

Claimed to accelerate recovery by:
Increases venous return
 Reduces exercise induced muscle damage
 Accelerates recovery processes
 Removes lactic acid faster
 Increases muscle oxygenations
 Improves body temperature control.

Replenishment of Fuels
Immediately after exercise:
 Replenish CHO stores by consuming 5100g high GI foods within first 15 mins of
finishing exercise. Eg. Jelly beans,
crumpets with honey, jam sandwich.
 Consume CHO and protein together
(4:1).

Glycogen Replenishment
Over next 2 hours athlete should
consume 25-50g CHO every 15 mins
(this maintains high insulin levels).
 After 2 hours CHO consumption should
continue at a rate of 50g every 2 hours
for 24 hours.
 It can take 24-48 hours to fully replenish
CHO.

Glycogen Levels
Post event glycogen
intake (High GI)
Within 1 hour
1-2 hours
5+ hours
Glycogen returns to
pre-exercise levels
55% restored in next 5
hours
100% restored within
24 hours
100% restored 24-48
hours
Up to 5 days
Role of Protein

Protein is broken down following intense
exercise.
 The addition of protein to CHO amplifies the
insulin response and promotes increased
glucose delivery to the depleted cells.
 Insulin stimulates protein synthesis and helps
reduce protein breakdown which assists in the
growth and repair of muscle tissue.
Hydration
Assessing fluid requirements:
 1. Weigh yourself before and after training and
competition.
 2. One kg of weight lost = 1 litre of fluid lost = 1-1.5
litres of fluid required. Aim to drink similar amount of
fluid in future training and competition to prevent
dehydration.
 Hydration during events: 250ml isotonic sports drink
every 15 mins.
Isotonic- similar to blood composition
Hypertonic- > sugars
Hypotonic- < sugars.
Sports Drinks
Contain CHO and electrolytes and
flavouring making it easier to drink.
 Contain sodium which aids in retention of
fluid without stopping thirst mechanism.
 Aid in replenishment of glycogen.
Consume 500-1000ml per hour of
isotonic drinks in end.
 Are emptied from stomach faster than
water (if CHO content of 6-8%).

Dehydration


Occurs when fluid loss exceeds fluid intake.
Effects include:
Mental meltdown, Decreased reaction times,
concentration and decision making.
Elevated body temperature leads to increase blood redistributed to the skin in an effort to cool down.
Decreased blood to muscles and decreased O2
available and increased reliance on LA system and H+
accumulate.
Blood thickens- harder to pump, less blood delivered
to the muscle and decreased amount of O2 available
for aerobic glycolysis and to oxidise LA.
Revision Questions
1.
2.
3.
4.
5.
6.
7.
After an intense game of netball, would a passive or active
recovery be required and why?
What other non-dietary strategy could the netball player use as
part of her recovery?
A football player received some heavy knocks during the game.
What type of recovery strategy may be useful?
A Tour de France cyclist has completed a 180km stage ride.
What is the first thing he should do to speed his recover?
Name 3 recovery strategies that can decrease venous pooling
and assist venous return.
A dietary strategy is to ingest CHO protein in a 4: 1 ratio. How
does this improve recovery?
Is pasta or jelly beans better for recovery?
ANSWERS
References

Malpeli, R. , Horton, M., Davey, G., &
Telford, A. (2008). Nelson Physical
Education VCE Units 3 & 4 (4th ed).
South Melbourne; Cengage.