What are vitamins
- Water soluble
- Fat soluble
organic compounds that must be obtained from the diet (except vitamin D & K)
Water soluble
- Vitamin C
- Vitamin B’s (1,2,3,6,12)
- Pantothenic acid
- Biotin
- Folic acid
Fat-soluble
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
Function of vitamins
- Energy Metabolism
- Cofactors in glycolysis
- Beta oxidation
- TCA (e.g. B vitamins)
- Red & white blood cell production
- Vitamin B12
- Assist in bone, connective tissue & cartilage formation
- Vitamin’s C & D
- Antioxidants
- Vitamins A, C & E
Minerals
Inorganic compounds found in nature, essential in human diet
Macrominerals
- Potassium
- Sodium
- Chloride
- Calcium
- Magnesium
- Phosphorus
- Sulfur
Microminerals
- Copper
- Zinc
- Iron
- Flourine
Function of minerals
- Building blocks for other tissue
- Bone heath (e.g. calcium, phosphorus
- Oxygen transport
- Hemoglobin & myoglobin
- Energy metabolism
- Cofactors in glycolysis, beta oxidation & the TCA cycle (e.g. zinc, magnesium, copper)
- Electrolytes
- Body fluids (e.g. sodium)
Mineral intake in athletes
Regular exercise (particularly in hot environment)
- Loss of several minerals in urine and sweat
* Iron and zinc → intake requirements increase for athletes engaging in heavy training
\+ Other deficiencies are rare
* Magnesium → Lost in sweat. Increased urinary loss of both magnesium and zinc during high intensity exerciseMineral loss in sweat
Sweat rate
- 2L/h
Loss of iron through sweat
- 0.3 mg/L
Only about 10% of ingested iron is absorbed
Exercise, vitamins & micronutrients
- Things to watch out for
- Diet & mineral absorption
- Loss of minerals in urine & sweat
- Anemia
- Low-energy, vegetarian & unbalanced diets
- Lack of sunlight exposure
Do micronutrients provide an ergogenic effect?
Vitamins
- Early research suggested there was an ergogenic effect
- This research was poorly conducted
* No control condition
* Didn’t know state of participants prior to intervention
- Recent doubled blinded control studies show that there is NO ergogenic effect of vitamins
If you correct a deficiency performance gets better - meeting the general vitamin and mineral requirement and not increasing amount over the recommended level
Supplements
- What are supplements
- Rules and regulations
Something added to complete a thing, supply a deficiency, or reinforce or extend a whole.
Rules and regulations
- Prescription Drugs are tightly regulated
- Dietary supplements are NOT tightly regulated
Caffeine
- effect on performance
- dose
- Peaks in blood after 60 mins
Performance
- Exercise intensities 85% of VO2max
- Improvements of 10% to 20% in time to exhaustion
- Magnitude of the performance enhancing effect increases as the duration of exercise increases
Dose
- Between 2 to 6 mg/kgBW ~ 1 hr prior to exercise
- Aerobic & Anaerobic-based events
Caffeine
- Mechanism of action
- Habitual caffeine consumers
- Side effects
- Increased lipolysis
- Indirectly through an increase in circulating epinephrine levels
- Directly through antagonising the adenosine receptors that inhibit hormone sensitive lipase and FA oxidation
- Increased muscle contractility
- Increase in the influx of calcium
- Increase calcium release from the SR
- Increase sensitivity of myofilaments to calcium
- Decreased perception of effort
- Not clear but likely linked to:
+ Catecholamine release and release of neurotransmitters
- Not clear but likely linked to:
Do habitual caffeine consumers have an altered response?
- Performance is unaffected
Side effects
- For people who don’t normally drink caffeine:
- GI distress
- Headaches
- Tachycardia
- Restlessness
- Nervousness
- Irritability
- Tremor
- Elevated BP
- Premature left ventricular contractions
Creatine
- What is creatine
- Replenishment
- Creatine in metabolism
- Performance
What is creatine
- Naturally occurring compound
- Not essential – can be synthesized by the body
- Present mostly in muscle tissue (95%)
- Approx. two thirds are PCr – the remaining is free creatine
Replenishment
- About 1-2% is broken down to creatinine and excreted in the urine
- Replenish 1-2 g creatine per day (unsupplemented)
Creatine in metabolism
- Combine with phosphoryl group to form PCr through the enzyme reaction creatine kinase (CK)
- Maintain the availability of ATP
- PCr depleted within 5 sec of high intensity exercise
Performance
- Positive effect on performance
- Enhanced recovery for high intensity exercise
Creatine
- Dose
- Mechanism
- Side effects
Dose
- 5 g for 5 days (3 to 5 g/day for 28 days)
Mechanism
- Increased PCr availability
- Increased PCr stores in the muscle improve contractile function by maintaining ATP turnover.
- Increased rate of PCr resynthesis
- Short recovery periods during repeated bouts of maximal exercise.
- Increased use of PCr as an energy source could reduce anaerobic glycolysis and lactic acid formation.
- Creatine could buffer some of the hydrogen ions produced during high-intensity exercise
- Reduce hydrogen ion formation in the muscle and delay fatigue caused by increased muscle acidity.
- Creatine may have anabolic properties
Side effects
- GI, cardiovascular, and muscular problems;
- Nausea, vomiting, and diarrhea;
- Alterations in kidney and liver function;
- Muscle cramps;
- Elevated blood pressure.
Sodium bicarbonate
- Overview
- Buffering
- Dose
- Does it work
- Extracellular buffer
- Reduces muscle acidity and increases buffering capacity = improved performance
Buffering
- Intracellular buffering:
- Metabolic
- Intracellular protein
- Extracellular buffering
- Ventilation
- Kidneys
- Blood bicarbonate (HCO3-)
Dose
- 0.3 g/kg of sodium bicarbonate had an increase in performance
Does it work
- High intensity sprints: 2% improvement, reduced effect after 10 min
- Intermediate exercise: enhanced recovery
Sodium Bicarbonate
- Mechanism
- Side effect
- Alleviating side effects
Mechanism
- Motor pathway -> Muscle physiology -> whole body physiology ->
Side effect
- Nausea
- Flatulence
- Stomach cramping or bloating
- Belching
- Stomach ache
- Bowel urgency
- Diarrhea
- Vomiting
Alleviating side effects
- Ingestion periods
- 90, 60, 30 mins prior to competition
- 3x over a 30 min period - loading finishes
- 60 mins prior to comp
- Consumed with lotion
Beta-alanine
- Overview
- Dose
- combine with sodium bicarbonate
- Intracellular buffer
- Increased muscle buffering capacity to improve high intensity exercise
Dose
- 4 - 6g/day for 2-4 weeks
Combining with sodium bicarbonate
- No additional effect
