Combined Effect of Exercise Intensity With Nutritional Supplementation on Skeletal Muscle Function
Condition: Healthy Volunteers; Exercise Intensity; Neuromuscular Fatigue; Skeletal Muscle Adaptations
MeSH terms: Fatigue
Study type: Interventional

Summary: 
      The main objective of this study is to determine the effectiveness of a nutritional
      intervention (olive leaf extract) combined with a specific training session (MICT or SIT) on
      PDH activation (as well as other protein expressions) and exercise-induced muscle fatigue.
    

Detailed description: 
      Sprint interval training (SIT) is a form of interval training characterised by short bursts
      of intense exercise interspersed with rest periods. SIT is as, or more, effective than
      moderate intensity continuous training (MICT) for systemic and metabolic adaptations of
      muscles, despite a lower workload and shorter duration. However, the mechanisms underlying
      the metabolic response to SIT versus MICT are poorly understood. Our recent work (Zanou et
      al. 2021) suggests that increased pyruvate dehydrogenase (PDH) activity may explain why a SIT
      session led to greater changes in proteins involved in mitochondrial respiration compared to
      a MICT session.

      Recently, it was found that a natural and commercially available compound based on olive leaf
      extract could stimulate resting mitochondrial bioenergetics by activating the mitochondrial
      calcium uniporter (MCU), which is involved in calcium transport across the mitochondrial
      membrane, directly controlling PDH activity. The main objective of this study is to determine
      the effectiveness of an acute nutritional intervention (olive leaf extract) combined with a
      specific training session (MICT or SIT) on PDH activation (as well as other protein
      expressions) and exercise-induced muscle fatigue.

      Participants will be allocated to either a SIT (6 x 30 s all out sprints) or a MICT (1h at
      50% maximal aerobic power) group and asked to come to the laboratory for five visits
      including one familiarization session with a triangular test for maximal aerobic power
      determination, the first experimental session during which they will realize the exercise
      with the product or a placebo and a session 24h after to assess skeletal muscle adaptations.
      Then after a 3 week wash-out period, they report to the laboratory for the fourth and fifth
      session, identical to the second and third sessions but with the other intervention (product
      or placebo). Muscle microbiopsies will be collected from the vastus lateralis muscle before,
      immediately after and 24 hours after exercise (MICT or SIT), while knee extensor
      neuromuscular function will be assessed at the same time points using voluntary and
      electrically-evoked contractions.
    

Intervention name(s): Olive leaf extract; Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): A capsule containing 250 mg of an olive leaf extract preparation will be swallowed with a glass of water before exercise.; A capsule containing 336 mg of cellulose microcrystalline will be swallowed with a glass of water before exercise.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The design is a placebo-controlled, double blind, cross-over two-arm study
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science