Health Adult Subjects
Conditions
Brief summary
Zone 2 training, a low-intensity endurance exercise performed at approximately 66-80% of VO₂max or near the first ventilatory threshold, has gained popularity for improving aerobic capacity, fat metabolism, and mitochondrial efficiency. It preserves glycogen stores and delays fatigue, making it an essential training method for both athletes and recreational exercisers. Nicotinamide adenine dinucleotide (NAD) is a vital metabolite that regulates cellular energy metabolism and redox homeostasis. It participates in oxidative reactions within the tricarboxylic acid cycle and electron transport chain, sustaining ATP synthesis and mitochondrial efficiency. Exercise influences multiple pathways of NAD metabolism, altering the NAD⁺/NADH ratio and thereby affecting energy production and fatigue resistance. Studies have shown that both aerobic exercise and NAD precursor supplementation (e.g., nicotinamide riboside \[NR\]) can elevate body NAD levels and enhance mitochondrial function, though findings remain inconsistent due to variations in dosage and participants' characteristics. This study aims to investigate how acute NR supplementation interacts with Zone 2 cycling training in adults. Specifically, it examines the temporal and dose-dependent effects of NR supplementation on metabolic flexibility and exercise performance. The results may clarify the potential synergistic benefits of combining NAD supplementation with low-intensity endurance training to improve aerobic adaptability.
Interventions
DIETARY_SUPPLEMENTNicotinamide Riboside (NR)
600 mg NR
Sponsors
ZHANG Jiaqi
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* Over 18 years old * BMI \<30 kg/m2
Exclusion criteria
* Present of health conditions that contraindicate participation in exercise training, such as a history of cardiovascular disease, cancer, or musculoskeletal disorders * Currently taking vitamin B supplements and/or NAD precursors * Taking medication that may affect the test results
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Substrate utilization (CHO and fat oxidation rate) | From enrollment to the end of treatment at 4 weeks |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Oxygen consumption | From enrollment to the end of treatment at 4 weeks | — |
| Heart rate | From enrollment to the end of treatment at 4 weeks | — |
| Blood glucose concentration | From enrollment to the end of treatment at 4 weeks | — |
| Blood lactate concentration | From enrollment to the end of treatment at 4 weeks | — |
| Peak power output | From enrollment to the end of treatment at 4 weeks | — |
| Mean power output | From enrollment to the end of treatment at 4 weeks | — |
| Rating of perceived exertion | From enrollment to the end of treatment at 4 weeks | — |
| Muscle pain scale | From enrollment to the end of treatment at 4 weeks | Muscle pain scale is a 5-point likert scale ranging from "1- Not at all" to "5- Extreme", with higher value indicating muscle pain. |
| Muscle fatigue scale | From enrollment to the end of treatment at 4 weeks | Muscle fatigue scale is a 5-point likert scale ranging from "1- Not at all" to "5- Extreme", with higher value indicating muscle fatigue. |
Countries
China
Outcome results
None listed