Background
Timing strategies to improve performance
Caffeine
Dietary nitrates
Documented evidence of timing benefit | ||||
---|---|---|---|---|
Nutrient/Dietary supplement | Mechanism of action | Purported benefit | Recommended dosing protocol | Timing-related references |
Caffeine | Adenosine receptor antagonist | ↑ fat utilization, ↑ mental drive, ↑ performance, ↓ perceptions of fatigue, ↑ force production, ↑ muscular endurance | Time: 2 h – 0 h Absolute dose: 100 mg – 300 mg Relative dose: 3–6 mg/kg body mass | |
Nitrates | ↑ nitric oxide ↑ blood flow ↑ muscular contractility ↓ O2 cost during aerobic exercise | ↑ endurance ↑ intermittent exercise | Time: 2–3 h prior Dose: Manufacturer recommendations | [31] |
Creatine monohydrate
Iron
Calcium
Timing strategies for performance and to mitigate adverse events
Sodium bicarbonate
Beta-alanine
Nutrient/Dietary supplement | Mechanism of action | Purported benefit | Recommend dosing protocol | Timing-related references |
---|---|---|---|---|
Documented evidence of timing benefit | ||||
Creatine | ↑ PCr ↑ ATP | ↑ High intensity exercise capacity ↑ Muscle mass ↑ Strength | Time: 10–12 weeks Absolute Dose: 5 g Relative Dose: 0.1 g/kg body mass | |
Iron | Oxygen transportation, DNA synthesis, Electron transportation | ↑ Aerobic Performance ↑ Oxygen Carrying Capacity | Time: 3–6 weeks Dose: 100 mg/day | |
Unexplored, but potential timing effect | ||||
Beta-alanine | ↑ Production of carnosine | ↑ High intensity exercise ↑ Resistance training volume ↓ Neuromuscular fatigue | Time: 4 x/day Dose: 1.3–1.6 g (6–7 g/day) | |
Calcium | Muscular contraction; Blunt ↑ levels of parathyroid hormone | ↑ Bone density ↓ Parathyroid hormone levels | Time: 60 min prior to exercise for up to 12 months Dose: 1000 IU/day | |
Sodium Bicarbonate | ↓ Metabolic acidosis | ↑ Repeated sprints ↑ High intensity exercise | Time: 1–3 h prior Relative Dose: 0.3 g/kg body mass | [58] |