Creatine And Nitrates

Question 1

What is creatine? (Endogenously Synthesised from…, where is it stored? diet)

Answer 1

• Endogenously synthesised from AA (arginine, glycine and methionine) in the liver, pancreas and kidneys
• > 95% is stored in the skeletal muscle
• Approx.. 50% obtained from the diet

Question 2

How is creatine stored? (Ratio of PCr and creatine, total creatine pool, upper limit, vegetarians)

Answer 2

• Two thirds = phosphocreatine (PCr) one third = free creatine
• total creatine pool (PCr + Cr) in the muscle averages about 120 mmol/kg dry muscle mass
• The upper limit of creatine storage is 160 mmol/kg dry muscle mass
• Vegetarians have lower intramuscular creatine stores (90-110mmol/kg dm)

Question 3

What is creatine turnover? (Synthesis, excretion)

Answer 3

• Synthesis approx 2g/day, 1g endogenous, 1g exogenous (diet)
• Excretion approx 2g/day, creatinine (urine)

Question 4

How to increase muscle creatine levels?

Answer 4

• 20grams per day for 6 days showed total creatine content increased in all subjects

Question 5

What are the effects of creatine and muscle hypertrophy?

Answer 5

• Upper body muscle hypertrophy favours the creatine group over the control
• Lower body muscle hypertrophy favours the creatine group over the control

Question 6

Talk about creatine metabolism during exercise (type II versus type I, maximal exercise, depletion, 80% resynthesised)

Answer 6

• PCr levels higher in type II fibres than type I fibres
• PCr levels decrease during maximal exercise
• PCr can be depleted in approx 10 seconds
• 80% resynthesised in approx 4 minutes

Question 7

Mechanisms of action? (What are the effects of creatine)

(Cr stores, glycogen, muscle damage)

Answer 7

^ Cr stores 30% = ^ PCr resynthesis
^ Muscle glycogen
Decreased muscle damage

Question 8

What is creatine monohydrate (CM)?

Answer 8

• White powder, 99% absorbed
• Better uptake mixed with a carbohydrate containing liquid or food

Question 9

Creatine loading protocols? (High-dose, low-dose, maintenance dose and washout period) ?

Answer 9

Short, high-dose protocol:
- 20g/day for 6 days
- 0.3g/kg BM for 6 days

Long, low dose protocol:
- 3-5g/day for 20-30 days

Maintenance dose:
2-5g/day

Washout period = 4-6 weeks

Question 10

When to consider creatine use?

Answer 10

• Single (+1-5%) and repeated bouts (+5-15%) of high-intensity exercise
• High-intensity max efforts <150 sec, largest effects on <30 sec tasks
• Power and strength sports, intermittent sports, resistance/interval training

Question 11

Other creatine uses?

Answer 11

• Endurance exercise- may improve sprint finish
• Concussion

Question 12

How does individual variability and sport type affect creatine effectiveness?

Answer 12

• Baseline levels of muscle creatine, high muscle creatine levels means they will experience little effects
• Sport type, for example ultra-endurance or exclusively skill-based sports

Question 13

Concerns of creatine consumption? (Body mass, myths)

Answer 13

• Increase in body mass (1-2kg) as a result of water retention
• Myths, no evidence that it causes kidney damage, muscle cramps, strains

Question 14

Safety issues of creatine consumption?

Answer 14

• No evidence of adverse effects with long term (4 years) use
• Mild, temporary gut upset can occur but can be attenuated with split dose, and avoidance of high fibre foods with ingestion
• Contamination

Question 15

What is nitrate? (NO*3, bioavailability, foods, intake)

Answer 15

• Dietary nitrate (NO*3 -)
• The ingestion of Nitrate leads to enhanced nitric oxide (NO) bioavailability
• High nitrate-containing foods include leafy greens and root vegetables
• Average intake is 1-2mmol/d (approx 60-120 mg/d)

Question 16

What is nitric oxide (NO)?

(Ingestion of dietary NO*3, skeletal muscle function)

Answer 16

• Ingestion of dietary NO*3- -> enhanced nitric oxide bioavailability
• Nitrogen oxide plays an important role in the modulation of skeletal muscle function

Question 17

What are the effects of Nitric oxide bioavailability? (Blood flow, type II, respiration, contractile function)

Answer 17

^ Blood flow to muscle
^ Function of type II fibers
^ efficiency of mitochondrial respiration
^ Muscle contractile function

Question 18

What is the effects of nitrates on exercise economy? (ATP cost, phosphorylation)

Answer 18

• Reduced ATP cost of muscle force production
• More efficient mitochondrial oxidative phosphorylation

Question 19

Supplement regime for nitrates? (Acute dose, chronic supplementation)

Answer 19

• Acute dose (2-3h pre-exercise), (5-9mmol) 310-560 mg nitrate
• Chronic supplementation (3-15 days pre-event), 310-560mg nitrate per day + 310-560mg nitrate pre event

Question 20

What should you avoid taking with beetroot juice?

Answer 20

Mouthwash or chewing gum as they interfere with its benefit

Question 21

Different types of food sources approximate to 1 x Beet IT Sports Shot (400 mg nitrate)?

Answer 21

• Beetroot (200g)
• Celery (250g)

Question 22

When to consider the use of nitrates?

Answer 22

• Endurance events lasting 4-30mins
• Training for aerobic fitness
• High-intensity intermittent events
• Exposure to hypoxic conditions (e.g., altitude training)

Question 23

Individual variability of nitrates?

Answer 23

• Few studies have investigated the impact on female athletes
• Athlete’s training status may also affect the efficacy. Highly trained endurance athletes (>65ml/kg/min VO2 max) not benefiting significantly

Question 24

Concerns and safety of nitrate consumption? (Beetroot, pink, nitrite, long-term, contamination)

Answer 24

• Beetroot juice can cause mild gut discomfort
• Temporary pink colour to urine
• Mistaken use of nitrite or nitrite salt as supplements can be toxic
• Long-term effects are unknown
• Contamination