Efficacy of phosphatidic acid ingestion on lean body mass, muscle thickness and strength gains in resistance-trained men

Abstract

BackgroundPhosphatidic acid (PA) has been reported to activate the mammalian target of rapamycin (mTOR) signaling pathway and is thought to enhance the anabolic effects of resistance training. The purpose of this pilot study was to examine if oral phosphatidic acid administration can enhance strength, muscle thickness and lean tissue accruement during an 8-week resistance training program.MethodsSixteen resistance-trained men were randomly assigned to a group that either consumed 750 mg of PA (n = 7, 23.1 ± 4.4 y; 176.7 ± 6.7 cm; 86.5 ± 21.2 kg) or a placebo (PL, n = 9, 22.5 ± 2.0 y; 179.8 ± 5.4 cm; 89.4 ± 13.6 kg) group. During each testing session subjects were assessed for strength (one repetition maximum [1-RM] bench press and squat) and body composition. Muscle thickness and pennation angle were also measured in the vastus lateralis of the subject’s dominant leg.ResultsSubjects ingesting PA demonstrated a 12.7% increase in squat strength and a 2.6% increase in LBM, while subjects consuming PL showed a 9.3% improvement in squat strength and a 0.1% change in LBM. Although parametric analysis was unable to demonstrate significant differences, magnitude based inferences indicated that the Δ change in 1-RM squat showed a likely benefit from PA on increasing lower body strength and a very likely benefit for increasing lean body mass (LBM).ConclusionsResults of this study suggest that a combination of a daily 750 mg PA ingestion, combined with a 4-day per week resistance training program for 8-weeks appears to have a likely benefit on strength improvement, and a very likely benefit on lean tissue accruement in young, resistance trained individuals.

Vastus lateralis exhibits non‐homogenous adaptation to resistance training

“…Previous studies have used narrow field‐of‐view imaging snapshots at both the VL0 and VL5 locations to quantify MT, PA, and FL in the VL. However, little consensus exists regarding the rationale for anatomical landmark selection during ultrasound assessment of the VL.…”

Training-induced changes in architecture of human skeletal muscles: Current evidence and unresolved issues

“…However, since the repeatability of measurement was not so good (the CV of repeated measurements was 13.5%), it may be the reason for the lack of changes in pennation angle. Hoffman et al 92) found an increase in VL thickness after resistance training for 8 weeks, but did not find such an increase in its pennation angle. Because the subjects in Hoffman et al 92) were resistance-trained men, and because adaptation of the pennation angle of VL was large within several weeks from the beginning of the training program 46) , the lack of change in the pennation angle of VL may have been due to its low responsiveness.…”

“…Hoffman et al 92) found an increase in VL thickness after resistance training for 8 weeks, but did not find such an increase in its pennation angle. Because the subjects in Hoffman et al 92) were resistance-trained men, and because adaptation of the pennation angle of VL was large within several weeks from the beginning of the training program 46) , the lack of change in the pennation angle of VL may have been due to its low responsiveness. Lack of pennation angle adaptation was also demonstrated in MG 93,94) and BF 56) , but these studies did not provide data on changes in muscle size.…”

“…Some studies failed to find a change in pennation angle despite significant muscle hypertrophy 9,43,91,92) . Rutherford and Jones 9) measured the pennation angle of VL and VI before and after knee extension training for 12 weeks, and failed to find significant changes in either of the two muscles.…”

Mechanosensitive Molecular Networks Involved in Transducing Resistance Exercise-Signals into Muscle Protein Accretion

“…With regards to human studies, one resistance exercise training study has employed oral supplementation of PA, producing an increase in lean body mass compared to placebo (Hoffman et al, 2012). …”