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The effects of beta‐alanine supplementation on physical working capacity at heart rate threshold
Author(s) -
SmithRyan Abbie E.,
Woessner Mary N.,
Melvin Malia N.,
Wingfield Hailee L.,
Hackney Anthony C.
Publication year - 2014
Publication title -
clinical physiology and functional imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.608
H-Index - 67
eISSN - 1475-097X
pISSN - 1475-0961
DOI - 10.1111/cpf.12111
Subject(s) - medicine , heart rate , ventilatory threshold , carnosine , cardiology , placebo , vo2 max , physical therapy , blood pressure , alternative medicine , pathology
Summary Beta‐alanine ( BA ) supplementation has been shown to delay neuromuscular fatigue as a result of increased muscle carnosine concentrations. Carnosine has also been found in brain and cardiac tissue. The physical working capacity test at heart rate threshold ( PWC HRT ) is a global estimate of the onset of fatigue during exercise, influenced by central and peripheral factors. The purpose of this study was to determine the effects of 28 days of BA supplementation on the PWC HRT . Thirty subjects (mean ± SD ; age: 21·0 ± 2·1 years; body mass: 72·7 ± 14·5 kg; height: 170·1 ± 7·9 cm) were randomly assigned to BA ( n = 15) or placebo ( PL , n = 15) groups. Testing included eight to nine total visits: an enrolment day, physical screening, peak oxygen consumption (V · O 2peak ) and two PWC HRT assessments over 4 days. Significant differences existed between BA and PL for PWC HRT ( P = 0·001; mean∆: BA ∆ = +24·2 watts, PL ∆ = +11·2 watts), but not for V · O 2peak ( P = 0·222), time to exhaustion ( TTE ; P = 0·562) or ventilatory threshold ( VT ; P = 0·134). Results suggest that BA may increase heart rate training threshold. These results, in combination with one previous study reporting a potential effect of BA on HR , suggest that future studies should evaluate both central and peripheral aspects of fatigue with BA intake.