Asahi Group’s Proprietary Ingredient Lactotripeptides Shown to Enhance Muscle Pump
During High-Intensity Exercise, Improve Motivation, and Increase Lean Mass in a Human
Clinical Trial

Asahi Group Foods, Ltd. conducted a human clinical trial to evaluate the effects of lactotripeptides (LTP) on exercise-related parameters. The results showed that intake of LTP enhanced muscle pump1) during high-intensity exercise, improved training motivation, reduced fatigue, and increased lean mass. The findings of this study were published on January 7, 2026, in the Journal of Exercise and Nutrition (Pinnacle Science). We plan to continue elucidating the underlying mechanisms of action and investigate the potential benefits of LTP in humans during exercise.

<Details below> Explanations of the terms are provided at the end.

■Research Background
Asahi Group has been conducting various functional studies on “Lactotripeptides (LTP)”, a proprietary ingredient of the Asahi Group derived from milk casein2) that originated from our research on fermented milk used in “Calpis”. LTP refers to two type of peptides3), Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP), which were originally identified as angiotensin-converting enzyme (ACE) inhibitory4） peptides[1]. Clinical studies using casein hydrolysates containing LTP have demonstrated blood pressure–lowering effects[2]. Subsequent studies have also reported improvements in vascular endothelial function[3], arterial flexibility[4], blood flow[5], and exercise-induced fatigue[6]. It has been reported that LTP promotes nitric oxide (NO) production in the blood[7], suggesting that LTP may exert its benefits via vasodilation. Based on this background, the present study evaluated the effects of LTP on muscles during exercise from a sports nutrition perspective.

■Study Methods
34 Japanese adult males with habitual resistance training were randomly assigned to one of three groups: (1) placebo group receiving a control food without LTP, (2) low-dose LTP (LD) group receiving 1.7 mg of LTP (VPP 0.7 mg, IPP 1.0 mg), or (3) high-dose LTP (HD) group receiving 3.4 mg of LTP (VPP 1.4 mg, IPP 2.0 mg). A randomized, placebo-controlled, double-blind, parallel-group study design was employed. Participants consumed the test food for 4 weeks. Before and after high-intensity leg exercise (an anaerobic power test using a cycle ergometer), thigh circumference, lean body mass, subjective muscle pump, training motivation, and fatigue were evaluated.

Figure 1. Study design

■Study Results
Effect on Post-Exercise Thigh Circumference
Over the 4 week period, post-exercise thigh circumference significantly increased in the high-dose LTP group compared to the placebo group.

Figure 2. Changes in post-exercise thigh circumference after intake of the test food over 4 weeks
* p < 0.05, Dunnett’s test (vs. placebo group)

Effect on Pre-Exercise Thigh Circumference and Lean Body Mass5）
Both pre-exercise thigh circumference and lean body mass were significantly increased in the high-dose LTP group after 4 weeks, whereas no significant changes were observed in the placebo group.

Figure 3. Changes in pre-exercise thigh circumference and lean body mass following intake of the test food
* p < 0.05, paired t-test (vs. baseline [week 0])

Subjective Evaluations (Muscle Pump, Motivation, Fatigue)
The results of evaluating subjective perceived effectiveness using a five-point Likert scale6）, the low-dose LTP group showed a significant increase in muscle pump compared to the placebo group at week 4. The high-dose LTP group showed a significant increase in training motivation on the next morning after exercise and a significant reduction in perceived fatigue, as reflected by the change in the pre-post difference, compared to the placebo group.

Figure 4. Subjective muscle pump following intake of the test food
* p < 0.05, Steel’s test (vs. placebo group)
Only groups showing a significant difference are presented.

Figure 5. 4-week changes in training motivation and fatigue following intake of the test food
* p < 0.05, Steel’s test (vs. placebo group)

■Terminology

1) Muscle Pump: A temporary condition in which muscles appear larger and firmer immediately
after resistance training due to increased blood flow.
2) Casein: One of the major proteins in milk; LTP are peptides produced by hydrolysis of casein.
3) Peptide: A compound consisting of two or more amino acids linked together.
4) Angiotensin-Converting Enzyme (ACE): An enzyme involved in blood pressure regulation through production of vasoconstrictive substances.
5) Lean body mass: Body mass excluding fat mass, commonly used as an indicator of muscle mass.
6) Five-Point Likert Scale: A questionnaire scale used to quantify subjective evaluations on five levels.

■References
［1］ Nakamura Y, Yamamoto N, Sakai K, Okubo A, Yamazaki S, Takano T. Purification and characterization of angiotensin I-converting enzyme inhibitors from sour milk. J Dairy Sci. 1995; 78: 777–783. doi: 10.3168/jds.S0022-0302(95)76689-9
［2］ Sano J, Ohki K, Higuchi T, et al. Effect of casein hydrolysate, prepared with protease derived from Aspergillus oryzae, on subjects with high-normal blood pressure or mild hypertension. J Med Food 2005; 8: 423–430. doi: 10.1089/jmf.2005.8.423
［3］ Uchida N,Osawa K, Oki K, et al. Effect of tablets containing lactotripeptides (VPP, IPP) on vascular endothelial function in healthy subjects -a randomized, double-blind, placebo-controlled trial. Jpn Pharmacol Ther. 2016; 44: 1025–1034
［4］Nakamura T, Mizutani J, Ohki K, et al. Casein hydrolysate containing Val-Pro-Pro and Ile-Pro-Pro improves central blood pressure and arterial stiffness in hypertensive subjects: a randomized, double-blind, placebo-controlled trial. Atherosclerosis 2011; 219: 298–303. doi: 10.1016/j.atherosclerosis.2011.06.007
［5］ Hatanaka M, Kanzato H, Nadaoka I, et al. Beneficial effect of lactotripeptide on peripheral blood flow in healthy volunteers: a randomized placebo-controlled double-blind study. Jpn Pharmacol Ther. 2021; 49: 73–82.
［6］Iwasa M,Aoi W, Nakayama A, et al. Milk casein hydrolysate alleviates muscle soreness and fatigue after downhill walking exercise in middle-aged to elderly men. Ann Sports Med Res. 2015; 2: 1045. doi: 10.47739/2379-0571/1045
［7］ Hirota T, Nonaka A, Matsushita A, et al. Milk casein-derived tripeptides, VPP and IPP induced NO production in cultured endothelial cells and endothelium-dependent relaxation of isolated aortic rings. Heart Vessels 2011; 26: 549–556. doi: 10.1007/s00380-010-0096-y

■Journal Information
Journal: Journal of Exercise and Nutrition, 2026, Volume 9 (Issue 1): 2
Publication Date: January 7, 2026
Title:
「Effects of Casein Hydrolysate Containing Val-Pro-Pro and Ile-Pro-Pro on Muscle Pump, Muscle Hypertrophy, and Motivation in Resistance-Trained Men: A Placebo-Controlled, Double-Blind, Parallel-Group Comparison Study」
Author: Takuro Ohigashi1, Koki Sato1, Misaki Hatanaka1, Masaaki Yasue1, Shohei Nakashima1, Yuri Miyamoto1, Yumi Aoyagi1, Shukuko Ebihara2, Toshiharu Namba3 and Motoyuki Tagashira1
(1 Asahi Group Foods, Ltd.、2 Chiyoda Paramedical Care Clinic、3CPCC Inc.,)