research institute for sports & exercise sciences faculty of science nutritional ergogenic aids...

Research Institute for Sports & Exercise SciencesFACULTY OF SCIENCE

NUTRITIONAL ERGOGENIC AIDS AND SWIMMING

DON MACLAREN


WHAT IS AN ERGOGENIC AID?

A product that purports to

Improve performance


ENERGY SOURCES, FATIGUE AND SWIMMING EVENTS


ERGOGENIC AIDS TO FOCUS ON

• Creatine

• Alkalinisers

• Caffeine

• Β-alanine/carnosine


ENERGY SOURCES: PCr


ATP

ADP

Cr Cr

PCr

ATP

ADPPCr

EXERCISE RECOVERY


CREATINE INGESTION: 5 days @ 20g/d

110

120

130

140

150

160

TC

r m

mo

l/kg

dm

Maximum loading


0 5 10 15 20 25

Days to complete loading

1-2 x 3g

4 x 3g

4 x 5g

CREATINE LOADING


CREATINE: how it may work?

• Increases Total muscle Cr

• Increases possibility of resynthesis of PCr

• Enhances muscle bufferingADP + PCr + H+ → ATP + Cr

• Causes muscle swelling and ↑ protein synthesis


STUDIES ON CREATINE

• Unlikely on single bouts• More likely to help repeated bouts• May not help running-based activities• More likely to help cycling ad swimming• Enhances Strength• Increases body mass


CREATINE & SWIMMING

• Single sprints – 9 studies (n=173)

7 NS; 2 → 2% improvement

• Repeated sprints – 10 studies (n=186)

9 studies – improvement

1 study – NS

• Body composition – 12 studies (N=183 )

7 No change (4-6 days)

5 → + 0.6-1% ↑ Body Mass


ENERGY SOURCES: ANAEROBIC GLYCOLYSIS

Lactate production


ALKALINISERS: how they may work?

• Enhance blood buffering (HCO3 and BE)

• NOT ↑ in muscle buffer

• Increases lactate and H+ efflux from cell


LACTATE EFFLUX

La

H+

MUSCLE CAPILLARY

H+

La

pH 7.4

HCO3

HCO3

pH – 7.0pH -6.5

CAPILLARY

HCO3

pH- 7.8

HCO3

HCO3

HCO3


STUDIES ON ALKALINISERS

• Unlikely to help short bouts <60s• More likely to help repeated short bouts• Can help in events lasting up to 30’• Chronic loading also helps• Variety of sporting activities


ALKALINISERS & SWIMMING

Gao et al (1988) EJAP 58:171

• 10 male college swimmers

• 5 x 100yds

• 0.25 g/kg HCO3 60’ before test

• 2 x HCO3; 2 x Pl; 1 x nothing


ALKALINISERS & SWIMMING

Pierce et al (1991) JSS 10: 255-259

• 7 male college swimmers• 1 x 100yd then 2 x 200yd

• Pl v C v HCO3 (0.2g/kg) given 60’ before swim

• 100yd – Pl (54.08); C (52.86); HCO3 (53.63)

• 2 x 200yd – HCO3 0.41% and 0.9% faster than C

Pl -1.11% and 0.02% compared with C• None of the results were significant


CRITERIA FOR POSITIVE USE OF BICARBONATE/CITRATE

• Dose – 0.3 g Kg-1 BM of HCO3 or citrate

• Timing – at least 90 min before exercise

• Period of ingestion – 30 to 60 min

• Events – 60 s or longerrepeated sprints (total work)


CAFFEINE: studies on endurance capacity


CAFFEINE: how it may work?

• Promotes adrenaline secretion

• Phosphodiesterase inhibition

• Adenosine antagonist

• Intra-cellular Ca2+ release


COSTILL (1978) MODEL OF CAFFEINE ACTION


CAFFEINE AND CALCIUM


CAFFEINE and ADENOSINE


CAFFEINE & SWIMMING

Collomp et al (1992)

• 7 Tr and 7 UTr swimmers• 2 x 100m with 20’ recovery• 250mg Caf or Pl 60’ before• Caf – P<0.01 improvement in swim velocity (Tr)• NS – UTr or Pl


CAFFEINE & SWIMMING

MacIntosh & Wright (1995)

• 7 Tr swimmers• 1500m • 6mg/kg Caf or Pl 150’ before• Caf – P<0.05 improvement

(20:58.8 v 21:21.8)• Also ↓ RPE in 100m warm-up

before swim


CAFFEINE, HCO3 & SWIMMING

Pruscino et al (2008) IJSNEM 18:

• 6 elite male• 2 x 200m with 30’ recovery

• Pl v HCO3 (0.3g/kg) v Caf (6mg/kg) v Caf+HCO3

• 1st 200m – Pl (2:03.77); B (2:03.01); C (2:02:42); C+B (2:01.69)

• 2nd 200m – Pl (2:04.22); B (2:02.62); C (2:03.90); C+B (2:01.70)

• NS – P=0.06


B-alanine and carnosine: the new kids on the block??

• Carnosine is a major intracellular buffer

• Carnosine is made from beta-alanine + histidine

• Could ingestion of either carnosine or beta-alanine

result in enhanced carnosine levels in muscle?

• If so, does this increase lead to an improvement in high intensity performance?


Β-alanine: new kid on the block!

Derave et al (2007) – JAP 103, 1736-1743

• 15 male athletes ingested 4.8g beta-alanine/day or Pl for 4 wk

• Increase in muscle carnosine (soleus & gastroc)• Increase in knee extension torque• No sig diff in 400m run or isometric endurance


Β-alanine: new kid on the block!

Hill et al (2007) Amino Acids 32:225-233

• 13 male subjects + 12 matched controls• B-alanine for 10 wks (4g/day)

• Total work done on cycle at 110% Wmax

• Muscle carnosine ↑ 58.8% (4wk) and 80.1% (10wk)• Increased equally in both Type I and Type IIa• TWD – ↑ 13% (4wk) and further 3.2% (10 wk)• TWD – unchanged in control


CONCLUSIONS

• Creatine – YES for repeated sprints

YES (?) for single sprints

• Alkalinisers – YES(?) for events > 50m

• Caffeine – YES for sprints and prolonged

• Β-Alanine – Potential (?) 50m-200m


OTHER AQUATIC SPORTS

• Diving

• Water polo

• Synchronised swimming

research institute for sports & exercise sciences faculty of science nutritional ergogenic aids...

Documents

research institute

pcr slide

cell slide

performance slide

g creatine loading slide

maximum loading slide

protein synthesis slide

swimming don maclaren