Concurrent training

Question 1

What are the proposed mechanisms for the interference effect?

Answer 1

1- impaired force generation (residual fatigue)
2- Chronic accumulated fatigue
3- inadequate glycogen supply
4- increased amino acid oxidation

molecular interference
- endurance training increases the AMP:ATP ratio within a muscle that activates the energy sensor molecule AMPK. In turn, the leads to the activation to TSC1/2 blunting mTOR (reduction in myofibrillar synthesis) and activation of the FOXO pathway (increase in protein degradation).

Question 2

What are the effects of training status on the interference effect?

Answer 2

with increasing training status, the magnitude of the interference effect increases.

Untrained individual upregulate both PGC1a and mTOR pathways following a given exercise stimulus. However, with increasing training experience, upregulation of each pathway for the same given stimulus decreases. Thus a need for more specific and intense exercise stimuli are required to receive an adaptation.

Question 3

What were the key take aways from the KEY reading?

Answer 3

high volume, continous exercise training results in an interference effect- a blunting in strength gains- when incorporated into a concurrent training programme.

If HIIT or SIT is used instead, at least the same level of PGC1a activation in achieved, but due to less energy demand, AMPK is not activated, thus there is no blunting of mTOR and protein synthesis, and no activation of the FOXO protein degradation pathway.
(this is enhanced when SIT or HIIT is done via cycling)

in regard to training- whatever adaptaion response is most sought after should dictate the sequencing of training per day. However, when looking to maximise both adaptations recovery times of 6hr and 24hr are recommended for strength training and endurance training, respectively. Finally, depending on training goal, a ratio of 1:2 or 1:3 favouring the most crucial training adaptation should be programmed.