gms | German Medical Science

Objective: The aim of this research was to examine the impacts of ZMA supplementations during six weeks resistance training on testosterone and IGF-1 hormones and muscle damage markers (creatine kinase and lactate dehydrogenase) in untrained males.

Material/Methods: 27 untrained young male students (age: 21/27±1/65 years, height: 177/90±6/25 centimeters, weight: 68/24±10/26 kilograms, body mass index: 21/54±2/54 kg/m²) were voluntarily participated and randomly divided in three groups including ZMA group (n=10), ZMA-CHO group (n=9) and placebo group (n=8). The exercise protocol contained three resistance training sessions. Each session consisted of three sets with each set made of six movements. Movements were repeated eight times for the first three weeks and six times for second three weeks at 70% one repetition maximum. Blood samples (five cc from brachial vein) were drawn every 12 hours before and after fasting period to measure testosterone, IGF-1, CK and LDH. For data analysis, two-way REPEATED ANOVA and Bonferroni posthoc test were used.

Results: Results showed there were no significant differences in testosterone and IGF-1 in pre- and post-test among three groups. LDH was significantly decreased 22.5% and 25% in first and second group respectively. However, CK was not significantly deceased in second group (Table 1 [Tab. 1]).

Conclusion: Our data indicated that ZMA supplementation during six weeks resistance training led to non-significant increase in testosterone, IGF-1 hormones and CK enzyme (P>0.05) but, significant decrease observed in LDH (P<0.05). This result was under situations that consumed dosage in current study was 1/3 recommended values. So, it can suggested according with previous studies that ZMA supplement should be useful if supplementation done in higher dose [1], and more duration [2], [3].