25) *** Adaptations to Anaerobic Exercise *** Flashcards
4 Neural Adaptations in response to anaerobic/resistance training
Neural adaptations
1. Synchronization and recruitment of additional motor units
2. Increased rate coding of motor units
3. Increased neural drive
4. Autogenic inhibition
2 Skeletal mm adaptations in response to Anaerobic/Resistance training?
Skeletal muscle
1. Sarcoplasmic hypertrophy
2. Myofibrillar hypertrophy
Cardiovascular responses to Anaerobic training?
Acute response?
Resistance Training?
Cardiovascular
* Acute response: Blood pressure ↑ during weightlifting: sustained
muscular force increases resistance to blood flow
* Resistance training: concentric left ventricular remodeling
Anaerobic Power vs Anaerobic Capacity
Anaerobic power → rate of energy release by cellular metabolic processes that function without the involvement of oxygen
Anaerobic capacity (Maximal anaerobic power) → maximal capacity of the anaerobic systems (PCr and anaerobic glycolysis) to produce ATP
No single test adequately measures anaerobic power
* VO2max used as a measurement of aerobic fitness
With anaerobic training there are changes in skeletal muscle that reflect muscle fiber recruitment
At higher intensities, ? fibers recruited to a greater extent than ? fibers
Sprint/resistance activities use ? fibers more than aerobic activities
With sprint/resistance training:
* ? fibers and ? fibers undergo an increase in cross-sectional area
With sprint training:
* Reduction in % of ? fibers and increase in ? fibers
With anaerobic training there are changes in skeletal muscle that reflect muscle fiber recruitment
At higher intensities, type II fibers recruited to a greater extent than type I fibers
* Type I fibers can continue to be recruited
Sprint/resistance activities use type II fibers more than aerobic activities
With sprint/resistance training:
* Type IIa fibers and type IIx fibers undergo an increase in cross-sectional area
* Cross-sectional area of type I fibers increases to lesser extent
With sprint training:
* Reduction in % of type I fibers and increase in type IIa fibers (IIa greatest increase)
Anaerobic training is achieved through: (2)
- Changes occur following training that requires ? of the anaerobic energy transfer system
Anaerobic training is achieved through:
(1) Sprint
(2) Power training
Changes occur following training that requires considerable overload of the anaerobic energy transfer system
- Anaerobic training enhances the anaerobic capacity of the mm fibers being trained
ATP-PCr adaptations following Anaerobic training?
Adaptations in the ATP-PCr system following anaerobic training:
* Conclusions: the major value of training bouts that last only a few seconds (sprints) is the development of strength
* Perform task with less effort and reduces risk of fatigue
May or May not see changes in enzyme levels
ATP-PCr dominates 3-15sec
Hard to isolate anaerobic system = hard to study
Glycolytic system Adaptations with Anaerobic training:
Anaerobic training increases activities of several glycolytic enzymes
Inconsistant but ulitmately studies show an increase in glycolytic enzymes. Unsure which enzymes or by how much.
Link between Energy systems and Hypertrophy?
Studies suggest that increases in muscle volume (hypertrophy) are associated with an adaption of the anaerobic energy metabolism
* Metabolic stress is an important factor in muscle hypertrophy (also GH, IGF-1 etc)
Regular resistance training leads to the adaptions of:
- anaerobic substrates of energy supply,
- increased quantity and activity of key enzymes,
- increased ability to generate high levels of blood lactate
- muscle volume (hypertrophy)
3 adaptations with sprint-power training:
(1) Increased levels of anaerobic substrates
* Muscle biopsies taken before and after resistance training reveal increases in the trained muscle’s resting levels of ATP, PCr, free creatine and glycogen, accompanied by an improvement in muscular strength
(2) Increased quantity and activity of key enzymes that control the anaerobic phase of glucose metabolism
* Greatest changes in anaerobic enzyme function and fiber size occur in fast twitch muscle fibers
* Note: changes do NOT reach levels seen in oxidative fibers (oxidative enzymes) following aerobic training
(3) Increased capacity to generate high levels of blood lactate during all-out exercise
* Enhanced lactate-producing capacity probably results from a training-induced increased levels of glycogen and glycolytic enzymes and improved motivation and “pain” tolerance to fatiguing exercise
“Central desensitization”
Type II fibers change more with anaerobic, type 1 with aerobic
Changes in anaerobic power and capacity occur without concomitant increases in aerobic functions
