PAKs supplement improves immune status and body composition but not muscle strength in resistance trained individuals
Journal Title (Medline/Pubmed accepted abbreviation): J Int Soc Sports Nutr
Year: 2010
Volume: 7
Number: 36
Page numbers: 1-6
doi: 10.1186/1550-2783-7-36

Summary of Background and Research Design

Background:Mixed formula supplements are very popular among recreational and professional weightlifters. Often known as PAKs, these dietary supplements consist of several pills/tablets packaged in the same envelope and are meant to be ingested together. They are intended to provide the consumer with all the supplements and nutrients needed for a training session and for specific situations in a single dose. The nutritional properties of the individual compounds are usually well established and the combinations are designed to promote maximum performance, serve as an energy source or a coenzyme in the pathways related to exercise, and act as an ergogenic aid. These supplements are usually are often brought to market quickly such that little is known about the chronic effects of these combinations.

Hypothesis/purpose of study:To evaluate the effects of chronic (4 week) PAK supplementation in combination with strength training on body composition, immune status, and performance measures in recreationally trained individuals with or without PAKs supplementation

Subjects: Twelve healthy and non-smoking males who were recreational weightlifters participated in this study. The subjects were divided into either a placebo group (n = 6, age 28.6 ± 6.9 yr, height 174.0 ± 0.04 cm, weight 75.6 ± 10.2 kg) or PAKs group (n = 6, age 29.8 ± 5.7 yr, height 177.0 ± 0.06 cm, weight 74.7 ± 4.4 kg)

Experimental design:Parallel groups, placebo-controlled (not specified if treatment assignment was randomized or if the study was single- or double-blinded)

Treatments and protocol:Height, weight, and body mass index were calculated and body composition was estimated by 7-site skinfold. Four different training routines were performed each week that included 4 sets of 10 or more repetitions at 80% of 1 repetition maximal (1RM) with short rest intervals between sets (<60 sec). The 1RM loads were determined before supplementation and after 4 weeks of training. Bench press and lat pull-down exercises were evaluated for 1RM. Subjects ingested placebo or 1 PAK 30 minutes before the training session and every morning of non-training days. The PAK supplement was a mixed formula that contained protein, calcium, magnesium, zinc, caffeine (as guarana), amino acids (isoleucine, leucine, and valine), and vitamins B2, niacin, B6, folic acid, C, and E. Subjects maintained a balanced diet and were restricted from additional supplements or whey protein during the study. Immune status was evaluated by an upper respiratory tract infections questionnaire.

Summary of research findings:
  • The placebo group did not show any changes in body composition.
  • The PAK group showed a significant decrease in percentage of body fat (before: 22.19% ± 0.55%, after: 20.13% ± 0.78%, P < .05 compared to pre-test).
  • For the repetition maximum strength test, there were no significant changes between the PAK and placebo groups.
  • The placebo group reported more symptoms of respiratory infection (10.86 ± 3.69) than the PAK group (1.86 ± 1.42), suggesting that PAKs maintained immune function

Interpretation of findings/Key practice applications:

In this study, 4-week PAK supplementation, when used once daily in male recreational weightlifters, improved immune status and reduced body fat composition, but did not affect strength as assessed by bench press and lat pull down. Additional long-term investigations (≥ 12 weeks) are needed for definitive conclusions on the relationship between PAK supplementation and muscle strength. Further investigation is also needed into the effects of various combinations and strengths of PAK supplements on body fat composition, immune status, and strength. The immune system evaluation for this study needs to be combined with more extensive immune response investigations before any definitive conclusions on the link between PAK supplementation and immune status can be determined.

This study has a number of significant limitations. First, as specified earlier, it is unknown if treatment assignments were randomized or if the study was single- or double-blind. Second, the only measure of immune status was a self-reported questionnaire. Biochemical markers of immune status were not measured. Third, skinfolds were used to assess body composition. This methodology lacks the precision of other more “gold standard” methods (eg, underwater weighing or air displacement plethysmography, dual energy x-ray absorptiometry). Fourth, the statistical methods used were not identified in this paper.

Google Tracking Google Plus Tracking Twitter Tracking