The effect of 30 days of β-alanine supplementation (4.8 g per day) on resistance exercise performance and endocrine changes was examined in eight experienced resistance-trained men. An acute resistance exercise protocol consisting of 6 sets of 12 repetitions of the squat exercise at 70 % of one-repetition maximum (1-RM) with 1.5 minutes of rest between sets was performed before and after each supplemental period. Blood draws occurred at baseline (BL), immediate (IP), 15-minutes (15P) and 30-minutes (30P) postexercise for growth hormone, testosterone and cortisol concentrations. A 22 % (p < 0.05) difference in total number of repetitions performed at the end of 4 weeks of supplementation was seen between β-alanine (BA) and placebo (PL), and Δ mean power was greater in BA (98.4 ± 43.8 w) vs. PL (7.2 ± 29.6 w). Growth hormone concentrations were elevated from BL at IP and 15P for both groups, while cortisol concentrations were greater than BL at all time points for both BA and PL. No group differences were noted. No change from BL was seen in testosterone concentrations for either group. Results indicate that four weeks of β-alanine supplementation can significantly improve muscular endurance during resistance training in experienced resistance-trained athletes. However, these performance gains did not affect the acute endocrine response to the exercise stimulus.
Key words
endocrine - erogenic aid - strength - athletic performance
References
1
Asatoor A M, Bardon J K, Lant A F, Milne M D, Navab F.
Intestinal absorbtion of carnosine and its constituent amino acids in man.
Gut.
1970;
11
250-254
4
Dunnett M, Harris R C.
Influence of oral beta-alanine and L-histidine supplementation on the carnosine content of the gluteus medius.
Equine Vet J Suppl.
1999;
30
499-504
5
Gordon S E, Kraemer W J, Vos N H, Lynch J M, Knuttgen H G.
Effect of acid-base balance on the growth hormone response to acute high-intensity cycle exercise.
J Appl Physiol.
1994;
76
821-829
6
Hakkinen K, Pakarinen A.
Acute hormonal responses to two different fatiguing heavy-resistance protocols in male athletes.
J Appl Physiol.
1993;
74
882-887
7
Harris R C, Tallon M J, Dunnett M, Boobis L, Coakley J, Kim H J, Fallowfield J L, Hill C A, Sale C, Wise J A.
The absorption of orally supplied β-alanine and its effect on muscle carnosine synthesis in human vastus lateralis.
Amino Acids.
2006;
30
279-289
8
Hill C A, Harris R C, Kim H J, Harris B D, Sale C, Boobis L H, Kim C K, Wise J A.
Influence of β-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity.
Amino Acids.
2007;
32
225-233
10
Hoffman J R, Im J, Rundell K W, Kang J, Nioka S, Speiring B A, Kime R, Chance B.
Influence of muscle oxygenation during resistance exercise on the anabolic hormonal response.
Med Sci Sports Exerc.
2003;
35
1929-1934
11
Hoffman J R, Ratamess N, Kang J, Mangine G, Faigenbaum A, Stout J R.
Effect of creatine and β-alanine supplementation on performance and endocrine responses in strength/power athletes.
Int J Sport Nutr Exerc Metab.
2006;
16
430-446
12
Horinishi H, Grillo M, Margolis F L.
Purification and characterization of carnosine synthetase from mouse olfactory bulbs.
J Neurochem.
1978;
31
909-919
13
Kraemer W J, Gordon S E, Fleck S J, Marchitelli L J, Mello R, Dziados J E, Friedl K, Harman E, Maresh C, Fry A C.
Endogenous anabolic hormonal and growth factor responses to heavy resistance exercise in males and females.
Int J Sports Med.
1991;
12
228-235
14
Kraemer W J, Marchitelli L J, Gordon S E, Harman E A, Dziados J E, Mello R, Frykman P N, McCurry D, Fleck S J.
Hormonal and growth factor responses to heavy-resistance exercise protocols.
J Appl Physiol.
1990;
69
1442-1450
15
Kraemer W J, Ratamess N A, Volek J S, Häkkinen K, Rubin M R, French D N, Gómez A L, McGuigan M R, Scheett T P, Newton R U, Spiering B A, Izquierdo M, Dioguardi F S.
The effects of amino acid supplementation on hormonal responses to resistance training overreaching.
Metab Clin Exper.
2006;
55
282-291
16
Mannion A F, Jakeman P M, Dunnett M, Harris R C, Willan P L.
Carnosine and anserine concentrations in the quadriceps femoris muscle in healthy humans.
Eur J Appl Physiol Occup Physiol.
1992;
64
47-50
17
Parkhouse W S, McKenzie D C, Hochachka P W, Ovalle W K.
Buffering capacity of deproteinized human vastus lateralis muscle.
J Appl Physiol.
1985;
58
14-17
18
Perry T L, Hansen S, Tischler B, Bunting R, Berry K.
Carnosinemia: a new metabolic disorder associated with neurologic disease and mental defect.
N Eng J Med.
1967;
277
1219-1226
19
Ratamess N A, Hoffman J R, Ross R, Shanklin M, Faigenbaum A D, Kang J.
Effects of an amino acid/creatine/energy supplement on performance and the acute hormonal response to resistance exercise.
Int J Sport Nutr Exerc Metab.
2007;
17
608-623
20
Stout J R, Cramer J T, Mielke M, O'Kroy J, Torok D J, Zoeller R F.
Effect of twenty-eight days of beta-alanine and creatine monohydrate supplementation on the physical working capacity at neuromuscular fatigue threshold.
J Strength Cond Res.
2006;
20
928-931
21
Stout J R, Cramer J T, Zoeller R F, Torok D, Costa P, Hoffman J R, Harris R C, O'Kroy J.
Effects of β-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women.
Amino Acids.
2007;
32
381-386
22
Suzuki Y, Ito O, Mukai N, Takahashi H, Takamatsu K.
High level of skeletal muscle carnosine contributes to the latter half of exercise performance during 30-s maximal cycle ergometer sprinting.
Jap J Phys.
2002;
52
199-205
23
Suzuki Y, Ito O, Takahashi H, Takamatsu K.
The effect of sprint training on skeletal muscle carnosine in humans.
Int J Sport Health Sc.
2004;
2
105-110
24
Tallon M J, Harris R C, Boobis L H, Fallowfield J L, Wise J A.
The carnosine content of vastus lateralis is elevated in resistance-trained bodybuilders.
J Strength Cond Res.
2005;
19
725-729