Athletic Performance

Quick Summary

• Daily protein around 1.6 g/kg/day is well-established for resistance-training gains. Morton 2018 meta-regression (PMID 28698222, Br J Sports Med, 49 RCTs) identified a plateau in resistance-training muscle and strength gains around 1.6 g/kg/day; additional intake above this threshold produced no incremental benefit. Per-meal MPS triggering benefits from ~0.4 g/kg with leucine ≥3 g (Macnaughton 2016 PMID 27511985 40 g whole-body context; Churchward-Venne 2014 PMID 24284442 leucine MPS trigger).
• Creatine monohydrate is the most evidence-supported (robust) ergogenic. Kreider 2017 ISSN position stand (PMID 28615996), Branch 2003 meta (PMID 12945830), Lanhers 2017 upper-limb meta (PMID 27328852). Steady 3-5 g/day saturates muscle creatine over ~4 weeks; loading 20 g/day × 5-7 days is optional and reaches the same steady state.
• Caffeine ergogenic effect is robust and broad. Guest 2021 ISSN position (PMID 33388079, J Int Soc Sports Nutr) supports 3-6 mg/kg body weight ~30-60 min pre-exercise across endurance, anaerobic, and resistance contexts.
• β-Alanine is robust for the 1-4 min high-intensity capacity window. Hobson 2012 meta (PMID 22270875, Amino Acids), Saunders 2017 SR/MA (PMID 27797728, Br J Sports Med); loading 4-6 g/day for ≥4 weeks raises muscle carnosine and supports high-intensity capacity in the 1-4 min duration window. Effects in shorter (under 1 min) or longer (over 10 min) tasks are inconsistent — that part is moderate–mixed.
• Astaxanthin endurance/recovery signal is preliminary–emerging — not the same as blanket antioxidant dosing. Brown 2021 (PMID 32660833) reported improved 40 km cycling time-trial performance at 12 mg/day × 7 days in trained cyclists. The general "high-dose antioxidants blunt training adaptation" concern (vitamin C / E) does not automatically transfer to astaxanthin, but the trial base is much smaller than for protein / creatine / caffeine.
• BCAA-alone is not the protein answer. Wolfe 2017 review (PMID 28852372) — isolated BCAA without a complete protein matrix does not stimulate sustained MPS comparable to whole-protein feeding.
• This is not medical or coaching advice. Training and supplementation decisions belong with your coaching and clinical care team. The framework below is mechanism and evidence mapping, reproduced for educational reference — not for self-administration.

The Evidence Stack

The "evidence" column below describes the strength and direction of the athletic-context outcome evidence in qualitative terms — well-established, robust, moderate–mixed, preliminary–emerging, or null–negative. The S/A/B/C tier that grades how extensively an ingredient is studied (its evidence volume) lives on each linked ingredient page, not here.

The five gaps these ingredients address: 5 nutrition-gap mappings — daily protein adequacy, creatine dosing strategy, caffeine timing, β-alanine carnosine loading, and the antioxidant / endurance-adaptation trade-off. Each ingredient links to its evidence-first asxan.ai page.

How It Works

Each ingredient engages athletic biology by a different route — protein and leucine through muscle protein synthesis and the mTORC1 pathway, creatine through phosphocreatine energetics, caffeine through adenosine-receptor antagonism, β-alanine through intramuscular carnosine buffering, and astaxanthin through mitochondrial-membrane antioxidant support and recovery.

Protein → MPS → hypertrophy and recovery. Resistance-training stimulates muscle protein synthesis (MPS); leucine is the most potent amino-acid trigger of the mTORC1 / S6K1 pathway driving translation initiation. Tang 2009 (PMID 19589961) head-to-head acute MPS comparing whey, casein, and soy showed whey-induced peak MPS exceeds casein and soy in young men at rest and after exercise. Macnaughton 2016 (PMID 27511985) demonstrated that whole-body whey 40 g (vs 20 g) increased post-resistance-training MPS in young trained men. Morton 2018 (PMID 28698222) meta-regression across 49 RCTs identified ~1.6 g/kg/day as the daily plateau beyond which additional protein produced no incremental gain in resistance-trained adults.

Creatine → phosphocreatine resynthesis → high-intensity output. Creatine monohydrate raises intramuscular phosphocreatine stores, supporting ATP regeneration during repeated short-duration high-intensity efforts (sprints, multiple resistance-training sets). Kreider 2017 (PMID 28615996) ISSN position stand documented strength and lean-mass benefit across age groups; Lanhers 2017 (PMID 27328852) meta supports the upper-limb sub-context. Saturation: ~3-5 g/day for ~4 weeks reaches steady state; 20 g/day × 5-7 day loading is optional and produces no superior endpoint.

Caffeine → adenosine receptor antagonism → perceived exertion reduction and direct effects. Caffeine ergogenic mechanism includes adenosine A1/A2A receptor antagonism in the central nervous system (reducing perceived exertion), catecholamine release, and direct muscle effects. Guest 2021 (PMID 33388079) ISSN position synthesizes endurance, sprint, and resistance-training literature: modal effective dose 3-6 mg/kg ~30-60 min pre-exercise.

β-Alanine → muscle carnosine → intramuscular pH buffering. β-Alanine is the rate-limiting precursor for muscle carnosine synthesis; carnosine buffers H⁺ accumulation during high-intensity glycolytic effort. Loading 4-6 g/day for ≥4 weeks raises muscle carnosine ~40-80%. Saunders 2017 (PMID 27797728) SR/MA supports the 1-4 min capacity window as the modal effective duration zone.

Astaxanthin → mitochondrial membrane stabilization → endurance + recovery. Astaxanthin is a xanthophyll carotenoid that crosses cellular and mitochondrial membranes and quenches singlet oxygen with substantially higher capacity per mole than vitamin E or β-carotene in cell-free systems. Brown 2021 (PMID 32660833) reported improved 40 km TT cycling performance after 12 mg/day × 7 days in trained cyclists. The cluster also includes mobility / sarcopenia signals (Liu 2018 PMID 30259703 / Liu 2024 PMID 38243785 meta) and elderly aerobic training (Liu 2021 PMID 34110707) — consistent with a recovery / endurance support framing rather than a strength-supplement framing.

Body systems engaged: Musculoskeletal · Mitochondrial & Cellular Energy · Neurological & Cognitive. Mechanism tags: mTOR regulation · Protein synthesis / mTOR coordination · Free radical scavenging · Neurotransmitter modulation.

What the Trials Show — Including the Nulls

BCAA-alone is not a substitute for complete protein. Wolfe 2017 (PMID 28852372) review documented that isolated BCAA supplementation in fed-state participants does not produce a sustained MPS response equivalent to whole protein. BCAA in carbohydrate-fed athletes is largely redundant with adequate dietary protein.

Creatine is not a "natural anabolic steroid." Creatine increases intracellular body water and produces modest hypertrophy and strength gain at population mean — but the magnitude is typically a 0.5-1.0 kg lean-mass advantage vs placebo over weeks to months. It does not substitute for resistance training.

Caffeine is not safe at arbitrarily high doses. The Guest 2021 (PMID 33388079) effective window is 3-6 mg/kg; higher doses do not produce proportionally higher benefit and carry cardiovascular and anxiety risk. EFSA upper safety guidance is ≤400 mg/day total caffeine in healthy adults; pregnant adults much lower.

β-Alanine paresthesia is real and benign. Tingling sensation at 0.8-1.6 g single doses is expected; splitting the daily dose ameliorates it. Effects outside the 1-4 min duration window are inconsistent (Saunders 2017 PMID 27797728).

None of these ingredients treats or prevents any disease. This is a lifestyle / training context, not a treatment context.

Practical Notes

Timing and consistency matter more than megadosing — caffeine is acute and pre-exercise, creatine and β-alanine work by saturation over ~4 weeks, protein gains accrue over 8-12 weeks of training, and astaxanthin endurance signals rest on a short protocol. Doses below reflect published trial protocols and position-stand frameworks, reproduced for reference only.

Foundational stack · protein + creatine. Daily protein adequacy (~1.6 g/kg/day per Morton 2018 PMID 28698222) plus creatine 3-5 g/day (Kreider 2017 PMID 28615996) is the most evidence-supported single combination for strength athletes. The two work through orthogonal mechanisms (MPS vs phosphocreatine) and have additive effects. For an 80 kg trained adult, ~1.6 g/kg/day maps to ~128 g protein/day distributed across 3-4 meals at ~0.4 g/kg per meal.

Acute pre-exercise · caffeine. Guest 2021 (PMID 33388079) supports 3-6 mg/kg body weight ~30-60 min pre-exercise across endurance and high-intensity contexts; effect lasts ~3-5 hours. Best used acutely on key training or competition days — daily habituation reduces the ergogenic edge, so cycling caffeine lower on rest days preserves acute benefit.

Saturation window · creatine and β-alanine. Creatine 3-5 g/day reaches muscle saturation over ~4 weeks (Kreider 2017 PMID 28615996); loading 20 g/day × 5-7 days is optional. β-Alanine 4-6 g/day for ≥4 weeks raises muscle carnosine to a functional threshold for the 1-4 min capacity window (Saunders 2017 PMID 27797728). Loading both before high-intensity training blocks (e.g., CrossFit, hockey, repeated-sprint sports) is a literature-supported combination — β-alanine specifically targets the glycolytic window creatine does not buffer.

Per-meal MPS trigger · whey post-exercise. Macnaughton 2016 (PMID 27511985) supports 40 g whole-body whey post-resistance-training in young trained men for maximal MPS; Tang 2009 (PMID 19589961) supports whey > casein > soy for acute peak MPS in young adults. The leucine in 25-40 g whey already exceeds the per-meal MPS-triggering threshold (Churchward-Venne 2014 PMID 24284442).

Training-timeframe expectations. Meaningful strength and hypertrophy with adequate protein + resistance training emerge by 8-12 weeks; Morton 2018 (PMID 28698222) pooled trials predominantly 6-52 weeks. The astaxanthin 40 km TT signal rests on 12 mg/day × 7 days (Brown 2021 PMID 32660833) — a single short protocol pending replication. Sarcopenia mobility signals (Liu 2018 PMID 30259703) align with a 12-24 week resistance-training timeline in older athletic cohorts.

Dietary foundation. Supplementation is layered on top of adequate total energy and dietary protein, not a replacement for it. Individual tolerance, medication interactions, and training load belong with your coaching and clinical care team.

Related Goals & Ingredients

• Athletic Performance — the goal-level evidence stack for strength, power, and endurance ingredients.
• Longevity Stack — protein adequacy and creatine cross-reference the muscle-preservation and healthspan framing.
• Senior 60+ — per-meal MPS and protein 1.6 g/kg/day translate with an anabolic-resistance per-meal upward adjustment to ~35-40 g per meal.
• GLP-1 Companion — muscle preservation under caloric deficit becomes relevant when GLP-1 medication reduces appetite.
• Cognitive Support — caffeine acute cognition (alertness, reaction time) overlaps with the athletic acute-task framing.
• Linked ingredients: Protein · Creatine · Caffeine · β-Alanine · Astaxanthin.

Frequently Asked Questions

References

All PMIDs verified against PubMed. Effect sizes are reported as published.

1. PMID 28698222 · Morton et al. (2018) · Br J Sports Med · meta-regression across 49 RCTs · ~1.6 g/kg/day protein plateau for resistance-training muscle and strength gains
2. PMID 23134885 · Cermak et al. (2012) · protein supplementation meta-analysis · resistance-training adaptations including older / trained adults
3. PMID 27511985 · Macnaughton et al. (2016) · whole-body whey 40 g vs 20 g · post-resistance-training MPS in young trained men
4. PMID 19589961 · Tang et al. (2009) · whey / casein / soy head-to-head acute MPS in young men at rest and after exercise
5. PMID 24284442 · Churchward-Venne et al. (2014) · leucine as the per-meal MPS trigger
6. PMID 18175749 · Houston et al. (2008) · Health ABC cohort · dietary protein and lean-mass preservation
7. PMID 27807480 · Antonio et al. (2016) · high-protein intake (2.5-3 g/kg/day) one-year safety data
8. PMID 28615996 · Kreider et al. (2017) · ISSN position stand · creatine safety and efficacy
9. PMID 12945830 · Branch (2003) · early landmark creatine meta-analysis · body composition and performance
10. PMID 27328852 · Lanhers et al. (2017) · creatine upper-limb strength meta-analysis
11. PMID 33388079 · Guest et al. (2021) · ISSN position stand · caffeine 3-6 mg/kg pre-exercise ergogenic window
12. PMID 22270875 · Hobson et al. (2012) · Amino Acids · β-alanine meta-analysis on exercise capacity
13. PMID 27797728 · Saunders et al. (2017) · Br J Sports Med SR/MA · β-alanine and 1-4 min high-intensity capacity
14. PMID 28852372 · Wolfe (2017) · review · isolated BCAA does not sustain MPS comparable to whole protein
15. PMID 32660833 · Brown et al. (2021) · J Sci Med Sport · astaxanthin 12 mg/day × 7 days · 40 km cycling time-trial in trained cyclists
16. PMID 30259703 · Liu et al. (2018) · astaxanthin sarcopenia trial · mobility / function
17. PMID 34110707 · Liu et al. (2021) · astaxanthin with elderly aerobic training
18. PMID 38243785 · Liu et al. (2024) · astaxanthin fatigue + motor-function meta-analysis

Coverage Notes

Qualitative evidence convention. The Evidence Stack column grades the strength and direction of the athletic-context outcome (well-established / robust / moderate–mixed / preliminary–emerging / null–negative). The S/A/B/C tier that grades how extensively each ingredient is studied — its evidence volume — lives on the linked ingredient page, not here.

Ingredient-correction notes. Astaxanthin is framed as a preliminary–emerging endurance / recovery signal (single trained-athlete RCT plus older-adult mobility cluster), not a confirmed strength ergogenic. The general antioxidant-blunting concern (vitamin C / E) is contextual and not automatically transferred to astaxanthin's distinct mechanism. Where omega-3 is referenced across asxan.ai, it resolves to the omega-3 single-product page plus the standalone EPA (fish-first) and DHA (algae first-line) monomer pages, with any "omega-3/algae" reference resolving to Algae Oil; FDA omega-3 guidance is ≤2 g/day EPA+DHA from supplements, with total intake up to 3 g/day considered GRAS.

Regulatory boundary and educational reaffirmation. This is a non-commercial educational evidence-framework page, not a prescriptive training or supplementation plan. Trial findings are reported as published; none of these ingredients treats or prevents any disease. Training load, dosing, and supplementation decisions belong with the coaching and clinical care team. Position-stand and regulatory figures (ISSN, EFSA, FDA) are cited as reference only; this page targets international markets and does not address China NMPA positioning.