Effects of phosphatidic acid supplementation on muscle thickness and strength in resistance-trained men.
Study Goal
The researchers aimed to determine whether phosphatidic acid (PA) supplementation enhances muscle thickness and strength when combined with an 8-week resistance-training program.
Results Summary
The study found no significant differences in muscle thickness or strength gains between the PA and placebo groups, though all participants showed significant improvements in both measures after the training program.
Population
15 resistance-trained men (mean age 22.8 years, mean body fat 14.6%).
Effective Dosage
750 mg of PA daily.
Duration
8 weeks.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
phosphatidic acid (PA) supplementation | no change | muscle thickness of the rectus femoris (RF) | fifteen resistance trained men | PA: 3.6% ± 5.2%; PL: 3.2% ± 4.2%, p = 0.97 | did not reveal any group differences | #1 |
phosphatidic acid (PA) supplementation | no change | muscle thickness of the vastus lateralis (VL) | fifteen resistance trained men | PA: 23.4% ± 18.1%, PL: 12.5% ± 15.4%, p = 0.37 | did not reveal any group differences | #2 |
phosphatidic acid (PA) supplementation | no change | muscle thickness of the biceps brachii (BB) | fifteen resistance trained men | PA: 3.7% ± 6.4%, PL: 9.6% ± 12.4%, p = 0.86 | did not reveal any group differences | #3 |
phosphatidic acid (PA) supplementation | no change | muscle thickness of the triceps brachii (TB) | fifteen resistance trained men | PA: 15.1% ± 17.9%, PL: 10.7% ± 19.3%, p = 0.79 | did not reveal any group differences | #4 |
phosphatidic acid (PA) supplementation | no change | 1 repetition maximum (1RM) of squat | fifteen resistance trained men | PA: 8.4% ± 4.1%, PL: 8.1% ± 4.2%, p = 0.79 | no group differences were observed | #5 |
phosphatidic acid (PA) supplementation | no change | 1 repetition maximum (1RM) of deadlift | fifteen resistance trained men | PA: 10.1% ± 10.1%, PL: 8.9% ± 9.5%, p = 0.66 | no group differences were observed | #6 |
phosphatidic acid (PA) supplementation | no change | 1 repetition maximum (1RM) of bench press | fifteen resistance trained men | PA: 5.7% ± 5.5%, PL: 5.1% ± 3.0%, p = 0.76 | no group differences were observed | #7 |
8 week supervised resistance-training program | increase | each measure of muscle thickness | all participants | p < 0.05 | experienced significant improvements | #8 |
8 week supervised resistance-training program | increase | strength | all participants | p < 0.05 | experienced significant improvements | #9 |
The purpose of this study was to investigate the effects of phosphatidic acid (PA) supplementation on muscle thickness and strength following an 8 week supervised resistance-training program. Fifteen resistance trained men (22.8 ± 3.5 years; 80.6 ± 8.7 kg; 178.1 ± 5.6 cm; 14.6% ± 8.8% body fat) were randomly assigned to a group that either consumed 750 mg of PA or a placebo (PL). Testing was carried out before (PRE) and after (POST) training/supplementation for muscle thickness and strength. Muscle thickness of the rectus femoris (RF), vastus lateralis (VL), biceps brachii (BB), and triceps brachii (TB) muscles were measured via ultrasonography, along with 1 repetition maximum (1RM) of squat, deadlift, and bench press. Analysis of covariance (ANCOVA), using PRE values as the covariate, did not reveal any group differences for measures of muscle thickness in the RF (PA: 3.6% ± 5.2%; PL: 3.2% ± 4.2%, p = 0.97), VL (PA: 23.4% ± 18.1%, PL: 12.5% ± 15.4%, p = 0.37), BB (PA: 3.7% ± 6.4%, PL: 9.6% ± 12.4%, p = 0.86), or TB (PA: 15.1% ± 17.9%, PL: 10.7% ± 19.3%, p = 0.79). Likewise, no group differences were observed in changes in squat (PA: 8.4% ± 4.1%, PL: 8.1% ± 4.2%, p = 0.79), deadlift (PA: 10.1% ± 10.1%, PL: 8.9% ± 9.5%, p = 0.66), or bench press (PA: 5.7% ± 5.5%, PL: 5.1% ± 3.0%, p = 0.76) exercises. Collectively, however, all participants experienced significant (p < 0.05) improvements in each measure of muscle thickness and strength. Results of this study suggest that PA supplementation, in combination with a 3 days·week