Preclinical studies performed at Nestlé Research (NR) identified oleuropein as a novel activator of mitochondrial calcium import. This potentiated mitochondrial calcium uptake resulted in decreased phosphorylation of the enzyme pyruvate dehydrogenase (PDH), which is linked to its activation as a rate limiting enzyme for mitochondrial oxidation, as well as increasing mitochondrial oxygen consumption, resulting ultimately in decreases in muscle fatigue. In addition, NR demonstrated that during aging, mitochondrial calcium and oxygen consumption rates are decreased in isolated skeletal muscle fibers. The next step in the evidence development is to demonstrate efficacy of oleuropein for improved muscle energy and decreased physical fatigue in a healthy aging population.

Inclusion Criteria:

1. Male
2. 50 to 70 years old
3. BMI 18.5-29.9 kg/m2
4. Healthy as per medical history and investigator's/ physician's judgement
5. Having given informed consent

Exclusion Criteria:

1. Allergy/intolerance to the study product
2. >5% body mass change in the previous 3 months
3. HbA1c ≥ 6.5%
4. Blood pressure >140/90 mmHg
5. Participating in a structured (progressive) exercise program
6. Smoking
7. Diagnosed acute or chronic medical conditions that, in the opinion of the investigator, could impact study outcomes
8. Diagnosed musculoskeletal disorders
9. Chronic use of gastric acid suppressing medication
10. Unauthorized concomitant medications such as calcium antagonists (e.g. valproate), oral corticosteroids, anything that will prevent subjects from safely completing the study according to the investigator or medications / drugs known interfering with the expected mechanism of action of IP or to affect the outcome parameters
11. Alcohol (intake higher than 3 servings per day. One serving is 0.4 dl of alcohol, 1 dl of wine, or 3 dl of beer) or drug abuse
12. Overly imbalanced or restrictive diet (e.g. hyperproteic, vegan, ketogenic, etc.)
13. Subjects not willing and/or not able to comply with scheduled visits and the requirements of the study protocol
14. Any implants that would be a contra-indication for performing an MRI scan.
15. Participation in another study at the same time
16. Blood donation in the past 2 months

1. Male
2. 50 to 70 years old
3. BMI 18.5-29.9 kg/m2
4. Healthy as per medical history and investigator's/ physician's judgement
5. Having given informed consent

This is a single-centre, double-blind, placebo controlled, randomised 2-arms parallel group study.