The Fatigue of Resistance Exercise Flashcards
Why care about ‘fatigue’?
- So novices will ‘come back’ and train again
- Between 84‐97% of elite sports science practitioners measure fatigue
- Recovery
- Overtraining
- Readiness to play
What is fatigue? - Perceived component
HINT: a potentially..
- A potentially disabling symptom where physical and cognitive function is limited in the hours and days following an exercise session
- Can only be measured by self‐report
- i.e. fatigue sub‐scale of the POMS questionnaire (Profile of Mood State)
The interpolated twitch technique (ITT)
A test for assessing the level of voluntary muscle force generation, in which muscle twitches are evoked via percutaneous electrical stimulation.
Terminology
- Functional overreaching
- Non-functional overreaching
- Overtraining syndrome
- Functional overreaching (FOR): A short-term decrease in performance lasting days to weeks with subsequent performance supercompensation after a period of recovery.
- Non-functional overreaching (NFOR): Performance decrement is observed over a period of weeks to months, and while full recovery is achieved (although not always), no super-compensation effects are achieved.
- Overtraining syndrome (OTS): Long-term reductions in performance capacity observed over a period of several months.
Dose-response relationship
Fitness-fatigue model:
Relationship between fitness and fatigue is a continuum that depends on:
- Cumulative effect of the training load
- Cumulative level of neuromuscular and mental fatigue
- Level of deficit in recovery
- Length of time fatigue has accumulated
- Severity of the fatigue symptoms
When your fatigue is greater than your fitness which causes a decrease in performance, but over time fatigue decreases which causes fitness and performance to increase
Acute based work
STUDY: Neuromuscular fatigue and recovery after heavy resistance, jump, and sprint training
3 condition
1. Heavy resistance
2. Jump group
3. Sprint condition
- Both sprint and strength group has a higher increase in creatine kinase which was reduced to the same amount after 72 hours (back to baseline)
- Larger report of fatigue and muscle soreness from the strength and sprinting group than the jump group
- Strength group saw the largest decrement in peripheral resting twitch post exercise compared to the jump and sprint group.
- Strength group saw a larger decrease in MVC after exercise
- Around 48, recovery was equivalent across the groups
- Magnitude of central fatigue was modest
- The observes neuromuscular fatigue was both a central and peripheral origin, with a faster recovery of central, compared with peripheral neuromuscular fatigue
- During testing of fatigue, not really seeing central fatigue as the main driver of fatigue but more peripheral. It’s more of the contractile tissue that hasn’t fully recovered and not so much the central driver
Acute based work
STUDY: The fatigue of a full resistance exercise session in trained men
Hint: voluntary activation, voluntary torque, peripheral twitch
- Compared a normal training program (7 exercises; 3-4 sets)
- Very small decrements in voluntary activation. Central fatigue fully recovered after 1 hours of exercise
-The reduction in voluntary torque was longer lasting. Between 24 and 48 hours it was close to baseline - Peripheral twitch tends to be the most sensitive from immediate post with a bit of a linear increase back to recovery
Acute based work
STUDY: Changes in fatigue are the same for trained men and women after resistance exercise
- Compare males and females
- The time cause fluctuations are similar between males and females. Both showed similar trends in recovery. However the absolute amount for the different measurements were higher in males
Acute based work
STUDY: Acute hormonal and neuromuscular responses to hypertrophy, strength and power type resistance exercise
Hint: RDF and EMG
- Compared a hypertrophy, strength, and power.
- Work joules were matched between groups
- Between the strength and hypertrophy group, they both showed the largest decrements in force, RDF and EMG activity. Within 48 hours, groups are close to baseline
- The rate of force development (RFD)(how quickly the muscle can produce force) was longer lasting decays compared to the amount of maximal force for the strength group
Acute based work
STUDY: Comparison of the recovery response from high-intensity and high-volume resistance exercise in trained men
- post 30 minutes up to…
- High intensity (8 sets of 3 reps at 90% 1RM) vs high volume(8 sets of 10 reps at 70% 1RM) (was not volume matches
- Post 30 minutes up to the post 48 hours, there was a larger reduction in the high volume groups than high intensity group in the changes in counter movement jump peak power
- The amount of cortisol immediately up was higher in the high volume group which is also in line with the interleukin 6 (inflammatory marker)
- High volume group saw an increase in cross-sectional area post exercise (up to until 72 hours). This may not be from myofibril hypertrophy but from sarcoplasmic hypertrophy (cell swelling)
- Soreness ratings were higher in the High volume group
Acute based work
STUDY: Recovery of skeletal muscle contractility after high and moderate intensity strength exercise
-biphasic pattern
- High intensity (3 sets of 3 reps 100% of 3RM) vs moderate intensity (3 sets of 3 reps 70% 1RM). Both performed squats and front squats
- Recovery of force-generating capacity followed a biphasic pattern that was characterised by a rapid recovery within the 1st 3-7hr after exercise, a levelling off or a further decline between 11 and 22hr after exercise, followed by the second phase of recovery for the next 11hr.
- A reason for a biphasic response: it takes some time for the inflammation response to start. The inflammation response then starts to cause that decrement before going down as well.
Acute based work
STUDY: The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance.
- 100 barbell squats
- 100 barbell squats as 10 sets of 10 repetition. - extreme
- Not seeing full recovery for some of the measure until 7 days post exercise
- Shows how extreme we would have to train to cause a longer lasting fatigue
- From a normal resistance training program, it will take about 48hours to fully recover. This can take less for experienced resistance training (24hours).
- Longer lasting recovery for peripheral fatigue or resting twitch. Longer lasting fatigue that is evident.
Training based studies - FOR/NFOR
- if you do too much…
If you do too much volume at high intensities, we can see a reduction in some of the performance markers. Moderate volume seem to be the middle ground
Training based studies - FOR/NFORC
STUDY: Changes in human skeletal muscle contractility and hormone status during 2 weeks of heavy strength training
- leg press, leg curl, bench press
- 5 weeks of normal training, one week of rest, then 2 weeks of heavy training.
- Heavy training group saw an increase in the leg-press, however, there was a decrease in the leg-curl and bench press.
- Purpose was to induce overtraining
- No correlation between changes in testosterone and changes in 1RM leg curl or bench press
- Big increases in creatine Kinase
Training based studies - FOR/NFOR
STUDY: Pituitary-adrenal-gonadal responses to high-intensity resistance exercise overtraining
- Testosterone and cortisol
- overtraining
- Trained subjects
- In the overtraining group, there was a small negative trend. However, circulating testosterone and cortisol were not greatly affected by high-intensity exercise protocol.
- Overtraining causes significant decrements in 1RM leg strength
