Oral Ingestion of AA Blends

Number Treated/

Reference Control Age Sex Agent

Number of Oral/

Time of

Posttreatment (Highest Average

Doses IV Duration Ingestion Pretreatment Reported)

IGF-I IGF Diet

Base/ Post- (kcal/ Peak treatment protein) Conclusion

Isidori et al.3£

Suminski et al.168

Fogelholm 11 et al.169

15-20 M ARG + lysine

15-20 M ARG Lysine ARG

1 Oral Single Not given 15.4 ± 5 (ig/1 108 ± 7.4 (ig/1 0.9-3.0 dose @ 90 mina U/ml

22-23 M ARG+ 1.5 g lysine (C) of each Exercise + 0 placebo

Exercise + 1.5 g each ARG/LYS

19-35 M 6 g ARG, 6 g lysine, ornithine, daily

Oral Single dose

Oral Single dose

Oral Single dose

1 Oral 1 day Oral 1 day

1 Oral 1 day

Oral 1 day

2 Oral 6 days

Not given 7.3 ± 2.3 (ig/1 13.5 ± 7.5 (ig/1 NDe ® 30 min

Not given 4.8 ± 1.9 (ig/1 15.8 ± 4.2 |ig/l ND= ® 120 min

Not given 16.4 ±4.1 |ig/l 6.2 ± 4.1 (ig/1 ® 120 min

1 p.m./' p.m.

  • 2.5 (ig/1 -5.5 M.g/1
  • 2.5 (ig/1
  1. 06 ± 1.2 (ig/1 (no change compared to placebo and pretreatment; p < 0.55)
  2. 0 U/ml Not given Young nonexercising males may have an acute response to Arg/Lys supplementation during fasting given

Not given

Not given

Not given

AAs were not additive to exercise

Fry et al.170 28

Corpas 8/8

Lambert 7 et al.167

ARG, ornithine, lysine BCAAs

ARG + lysine

ARG + lysine

2.1 g argine, ornithine, lysine + 2.1 g BCAA + 50 mg gin 1.5 g each 2 times/day for 3 days, then 3 g of each twice daily for 11 days 2.4 g total

Oral 7 days

2 Oral 14 days

and 8

5 1-day visits (1 week between each)

6:00 A.M. and after fasting

Placebo,-104 ±57 ng min/mlcd

No change compared to placebo

  1. 7 ± 2.5 |xg/l; 142 ±58 12 h mean; (ig/1 1.2 ± 1.1 (ig/1
  2. 7 ± 117.2 ng min/mld

Not given

a Statistically significant increase from pretreatment value.

p 0.05 compared to pretreatment. c Placebo is the same as pretreatment since all subjects did a placebo trial in one of the five trials. d Values in ng min/ml over 180 min. » ND = No data.

W Ki

TABLE 15.6

Integrated Concentrations of Serum Growth Hormone (ng/min/ml-1) for 180 minutes after Ingestion of the Treatment or Infusion of rhGH

TABLE 15.6

Integrated Concentrations of Serum Growth Hormone (ng/min/ml-1) for 180 minutes after Ingestion of the Treatment or Infusion of rhGH

Subject

Placebo

A

B

C

rhGH

1

13.5

249.0

54.0

33.0

2

64.5

220.5

52.5

667.5

3605.9

3

441.5

357.0

709.5

1725.0

4

52.5

937.5

673.5

1597.5

644.3

5

21.0

42.0

30.0

415.5

800.9

6

85.5

144.0

723.0

49.5

654.3

7

51.0

36.0

39.0

36.0

325.5

Mean 104.2 283.7 325.9 646.3 1206.2a

Mean 104.2 283.7 325.9 646.3 1206.2a

Note: A = ARG/lysine; B = ornithine/tyrosine; C = Bovril®.

From Lambert, M.I. et al., Int. J. Sport. Nutr., 3(3), 303, 1993. With permission.

circulating levels of AAs may mimic the effects of exercise that lead to an increase in GH production. Increasing the blood levels of AAs, a condition that takes place during and immediately after exercise,256,258 may initially give a false signal of catabolism, which then triggers anabolism analogous to cell volumizing with different AAs.194

15.7.3.2.1.4 Time of Ingestion

Supplementation does not appear to amplify GH release during exercise, so ingesting Arg/Lys before training should not be of benefit to the GH response.168-170 Pulsatile and continuous intravenous administration of GH have demonstrated similar effects on raising GH, with the latter having a greater effect on raising IGF-1 in GH-deficient subjects.324,325 These results suggest that it may not be necessary to take advantage of the anterior pituitary (AP) when it is already primed for secretion. In all studies reviewed, with the exception of Fogelholm et al.'s,169 the supplemental AAs were taken in fasting states (or at least postabsorptive), presumably to take advantage of a primed AP.326327

Fogelholm et al.169 fed 11 competitive male weight lifters an Arg/Lys/Orn mixture 1.5 h after an 11:30 a.m. meal and 3 h after a 6:00 p.m. meal, over a period of 4 days. They periodically measured serum GH levels and found no difference between the supplemented and placebo groups. Arg/Lys/Orn supplementation appears to have no additive effect to other stimuli affecting GH release.

All dosages used in the trials mentioned previously were relatively small (Table 15.5) compared to infusions of AAs that show efficacy. These dosages were based on suggestions made by the product manufacturers.

15.7.3.2.2 Conclusions from Research

If AA supplementation or high-protein intakes stimulate GH secretion, the mechanisms involved may be the same as those for exercise.194,256,258 When supplementation is combined with other stimuli like exercise, an additive capacity for GH release by the AP does not occur, especially in older individuals. In other words, for someone 25 or more years old who is already participating in moderate to intense exercise and consuming between 1.8 and 2.2 g/kg of protein throughout the day, with a portion consumed with carbohydrate shortly after exercise, additional GH response may not be possible by any means other than continuous injections of GH. Conversely, for someone under the age of 20 not exercising and consuming a low-protein diet, Arg/Lys supplementation may exert a potential for increasing GH levels.

All in all, AA supplementation to increase GH seems to be an exercise in futility under most normal conditions. Even GH injections have shown little to no effect on skeletal muscle hypertrophy or performance additive to the effects of training.178-181

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