The Effects of a Novel Mitochondrial Substrate Supplement on Exercise Performance and Cognitive Function

This study is a randomised, placebo-controlled, cross-over trial investigating the effects of supplementing with a novel mitochondrial substrate supplement on exercise performance and cognitive function.

The supplement is composed of three bioactive components: choline, nicotinamide and succinate. All three components are available on the market as supplements and/or as food additives, but have not previously been combined.

This study will recruit 40 individuals in two cohorts. The first cohort will consist of 20 young individuals (aged 18-30) and the second cohort will consist of 20 older individuals (aged 50-65). Individuals will be block randomised into two groups within each cohort, taking either the placebo or supplement first. Trials will be counterbalanced by Latin square to remove any trial-order effect.

This study will involve 5 lab visits per participant, including a familiarisation visit and a further 2 visits per trial arm. Familiarisation will consist of questionnaires and cognitive tests, warm-up and ramp incremental test on a cycle ergometer for all participants. The ramp incremental test will commence with a 3-minute unloaded baseline period followed by an increase in work rate until task failure. Task failure will be defined as a drop by >10 rpm below participants' self-selected cadence (which is expected to lie between 70 and 100 rpm). Following a rest period, participants in the 'young' cohort will also complete a 3-minute all-out test on a cycle ergometer.

Participants will be supplemented with 65 mL.d-1 of either a placebo or the supplement twice daily for 16 days while recording food intake and exercise activities. On days 15 and 16 of supplementation, participants will return to the lab for testing. Testing on day 15 will consist of questionnaires and cognitive tests, a venous blood sample, and a 3-minute all out test (young cohort) or ramp incremental test (older cohort) on a cycle ergometer. Venous samples will be collected prior to exercise.

Testing on day 16 will consist of a series of three 6-min step tests, from unloaded to moderate intensity, with a 15-minute rest period between each test. Moderate exercise is defined as exercise which occurs below the lactate threshold. Participants will then complete an intermittent exercise protocol consisting of alternating 60-second periods of severe intensity exercise and 30-second periods of recovery until they reach the limit of tolerance. Severe intensity is defined as exercise which occurs above the critical power, where VO2max is reached at exhaustion. All tests will be conducted on a cycle ergometer.

Following completion of the first trial arm, participants will undergo a 28 or 46 (pre-menopausal females) day washout period. The washout period for young female participants is adjusted to enable all testing to occur in the same phase of the menstrual cycle and thus remove potential associated confounding effects. Participants will then repeat the supplementation protocol and testing visits on days 15 and 16 with the opposing supplement.

Inclusion criteria

• Participants will be deemed eligible to participate provided they are willing and able to follow the study instructions and

• are able to take part in intense exercise (as assessed via Physical Activity Readiness Questionnaire (PARQ))
• are able to consume a dietary supplement
• are not overweight/obese (assessed by BMI)
• do not have any cardiovascular, respiratory, metabolic or musculoskeletal disorders, or any other contraindication to the performance of maximal exercise.

Exclusion criteria

• Aged 31-49 and aged 66+.
• underlying illness or injury (assessed via PARQ)
• overweight or obese individuals (BMI of >30 kg.m-2).
• Cardiovascular, respiratory, metabolic or musculoskeletal disorders (assessed by screening form).
• Use of dietary supplements, tobacco smoking.
• Pregnant