Intermittent vs Continuous Training Flashcards
What does SPORT stand for?
Specificity Progression Overload Reversibility Time
What does FITT stand for?
Frequency
Intensity
Time
Type
Describe a typical moderate-intensity continuous training session?
60min (25-120min)
70% HRmax
50-80% VO2max/Peak aerobic power
Describe a typical high-intensity interval training session?
1-5min on ith a similar recovery period
6-20 repetitions
85-90% HRmax
75-100% VO”max/Peak aerobic power
Describe a typical sprint interval training session?
30sec interval with 4min recovery
4-7 repetitions
90-95% HRmax
170% peak aerobic power (all-out)
Flick Equation?
VO2 = CO x a-vO2diff
- CO = O2 delivery (central)
- a-vO2diff = O2 utilisation/extraction (peripheral)
Central adaptations to endurance training?
Lower HR at any given intensity and lower resting HR
Higher SV at any given intensity and greater maximal SV
Greater Q at maximal exercise and greater maximal Q
Increased haematocrit
Peripheral adaptations to endurance training?
Increased mitochondrial content and size
Increased maximal activity of oxidative enzymes
Increased glycogen concentration
Greater number of capillaries per muscle fibre (angiogenesis)
Decreased diffusion distance of O2, substrate, and metabolites between the blood and muscle fibres
Metabolic adaptations to endurance training during submaximal work?
Increased muscular uptake of fat from blood
Increased muscular utilisation of fat
Decreased muscular utilisation of glycogen
Decreased muscular production of lactate
How to stimulate red blood cell production?
With extended repeated exercise bouts?
How is red blood cell production increased with training?
Changes in oxygenation cause the kidneys to secrete the erythrocyte stimulating hormone erythropoietin (EPO) Stimulates RBC production in the marrow of long bones Increases haematocrit (concentration of RBC's) and haemoglobin
What are the implications of increasing haematocrit?
Increased blood volume
Increased the O2 carry capacity in the blood
Properties of RBC?
4 iron groups per haemoglobin molecule - each combine with 1 O2 molecule
Iron has a high affinity for O2 - facilitates O2 binding and transport
1g of haemoglobin can bind 1.34mL of O2
What is the role of PGC1a?
The master transcriptional factor in the mitochondria which brings about a wide variety of adaptation to the strain that is imposed by endurance exercise
The effect of endurance training on PGC1a?
Synthesis of new mitochondrial proteins
Synthesis of new blood vessels (microvessels, angiogenesis)
Muscle fibre type conversions
More oxidative phenotype
What molecule brings about skeletal muscle adaptations following training?
PGC1a
What stimulates PCG1a?
Low muscle glycogen - AMPK and MAKp38
ADP, AMP, Cr - AMPK
Calcium - CAMK II
Adrenaline - PKA
Effects of different training types on aerobic performance and cardiac output? (MacPherson et al. 2011)
Protocol - sprint interval training vs continuous endurance training
Results
- Greater increase in Q and SV following continuous endurance training
- Improvements in central adaptations to the heart are more effective with continuous endurance training
Influence of training intensity on the percentage improvement in VO2max?
Protocol - HIIT, MICT, and SIT
Results - HIIT is more effective than MICT and SIT at increasing SV, Q, and VO2max
Influence of training intensity on mitochondrial respiration and content? (Granata et al. 2016)
Protocol - HIIT, MICT, SIT
Results
- Greater improvements in mitochondrial respiration following SITmcompared to MICT and HIIT
- Greater improvements in signalling response following SIT compared to MICT and HIIT
- no changes in mitochondrial content following 4wks of SIT, MICT and HIIT
Training intensity vs volume on mitochondrial content? (Bishop et al. 2014)
Mitochondrial content response more to an increase in training volume
Mitochondrial respiration response more to an increase in training intensity
Importance of work-matching?
When work-matched HIIT is a far more effective stimulus at switching on PCG1a and increasing citrate synthase activity compared to MICT
When non-work matched HIIT and MICT are equally affective at switching on PCG1a and increasing citrate synthase activity
Egan et al. 2010
Protocol - Work-matched - HIIT vs MICT Results - HIIT is far more effective at switching on PCG1a compared to MICT
Macinnis et al. 2017
Protocol - Work-matched - HIIT vs MICT Results - HIIT is far more effective at increasing citrate synthase activity compared to MICT
Burgomaster et al. 2008
Protocol - Non-matched - HIIT vs MICT Results - HIIT and MICT are equally effective at switching on PCG1a and increasing citrate synthase activity
What determines sports performance?
Aerobic synthesis of ATP
Effects of training on fat and carbohydrate oxidation?
After training at any given submaximal velocity, fat oxidation is increased and CHO oxidation is increased
Effects of endurance training on muscle metabolic homeostasis?
Less PCr utilisation
Less glycogen utilisation
Less acidosis
Effects of training on muscle buffering capacity? (Gibala et al. 2006)
Protocol - SIT and MICT
Results
- Muscle buffering capacity is increased following both SIT and MICT
- Better able to cope with acidosis post-training
Effects of SIT on muscle ion transporters? (Mohr et al. 2007)
Increased NHE (Na+/H+ exchanger isoform) Increased MCT (muscle monocarboxylate transporter) Increased Na+/K+/ATPase
Effects of training on muscle fibre recruitment?
Less recruitment of type II muscle fibres at the same exercise intensity
Beneficial since type II muscle fibres are less economical (require more energy) and become fatigued quicker
Effects of exercise training on VO2max?
Training increased VO2max
Once VO2max is attached extra ATP requirements are met through anaerobic metabolism
Resulting in rapid metabolite accumulation
Resulting in rapid depletion of anaerobic substrates
Meaning exhaustion is imminent
Effects of exercise training on exercise economy>
Training improves exercise economy
Less oxygen uptake required at any given absolute exercise intensity
Effects of exercise training on neuromuscular fatigue development and pain tolerance? (O’leary et al. 2017)
Protocol - HIIT vs MICT
Results
- less central fatigue development after HIIT can induce a greater level of peripheral fatigue
- greater improvement in pain tolerance following HIIT compared to MICT
Adaptations following endurance training that improve performance?
Increased Q and SV
Increased fat oxidation and decreased CHO oxidation
Decreased muscle glycogen and PCr
Decreased ADP, Pi, H+, K+, and lactate accumulation
Decreased muscle afferent feedback
Decreased central fatigue
Increased pain tolerance
Allows the development of greater peripheral fatigue
Association between endurance exercise training improves performance?
Endurance exercise performance is improved following HIIT, MICT, and SIT, but the mechanism of action differs
Why does endurance training improve endurance performance?
More economical - use less energy
Depletes the energy reserves less - improves economy and fat oxidation spares muscle PCr and glycogen)
Produces less metabolites linked to muscle fatigue (MDP, Pi, H+)
All enables the ability to run faster for the same depletion of energy reserves and metabolite accumulation as before training
Considerations when selecting continuous or interval training to develop endurance?
SIT can;
- Increase skeletal muscle hypertrophy
- Increase % of type IIa bibres
- Increase capilliarisation
- Improve aerobic and anaerobic metabolism
- Improve sprint, repeated sprint, and endurance performance at lead up to 10km)
SIT should be the training of choice for athletes wishing to also improve strength performance
SIT should also be used by team sports due to the numerous metabolic and performance improvements
MICT is more important for long-distance athletes
Effects of training in already trained athletes? (Bangsbo et al. 2009)
Protocol - normal training vs SIT
Results - SIT saw greater improvements in running endurance performance compared to normal training
Considerations for training in already trained athletes?
Endurance athletes should consider some HIIT and SIT at the expense of some high-volume MICT
However, they still need to complete some high-volume MICT
