Study note • PMID 25941925
Whey or Casein Hydrolysate with Carbohydrate for Metabolism and Performance in Cycling.
Low risk + high feasibility for most athletes.
ELI5
In plain language
The protein type most suitable for ingestion during endurance exercise is undefined. (randomized trial; cyclists).
Effects on Time-trial performance, Fat oxidation are mixed or unclear from the abstract alone. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.
Takeaways
What the abstract suggests
- • Study question: The protein type most suitable for ingestion during endurance exercise is undefined.
- • Effects on Time-trial performance, Fat oxidation are mixed or unclear from the abstract alone.
- • Population: cyclists.
- • Protocol cues (title/abstract): 2 h.
Protocol
Protocol (as reported)
- • Intervention/exposure: carbohydrate, carb (vs placebo).
- • Dose/time/duration cues in abstract/title: 2 h.
- • Outcomes: Time to exhaustion, Time-trial performance, Fat oxidation.
- • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.
Fit
Who it helps, and who should skip it
Who it helps
- • Athletes similar to the study population (cyclists) working on fueling.
- • Athletes who can measure Time to exhaustion, Time-trial performance, Fat oxidation with a repeatable workout or time-trial effort.
Who should skip
- • If you have symptoms or conditions that make the intervention risky, get professional guidance.
- • If you’re near race day and can’t safely test, defer the experiment.
Methods
What the study actually did
- • Design: randomized trial (double-blind, placebo-controlled).
- • Population: cyclists.
- • Comparator: placebo.
- • Outcomes measured: Time to exhaustion, Time-trial performance, Fat oxidation.
- • Protocol cues mentioned: 2 h.
- • Source: PubMed PMID 25941925 (2015) — International journal of sports medicine.
Results excerpt
What the abstract reports
“However, neither protein hydrolysate enhanced time trial performance when compared with carbohydrate-only.”
Note: excerpts are short; for full context, read the paper.
Limits
Limitations & bias
- • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
- • Single studies often don’t generalize to your event, history, and training load; treat results as a starting point.
- • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
- • This is performance information, not medical advice.
Coaching beta
Get a plan that adapts to your life.
Join the 26weeks.ai TestFlight beta for adaptive coaching, recovery-aware adjustments, and race-week reminders.
Keep going
Performance Science Lab
Research-backed protocols and evidence grades for endurance performance — built for athletes.
Fueling performance research
Fueling is performance, not just health: the right carbs at the right time change outcomes.
Caffeine for endurance performance: a practical protocol
Evidence-informed protocol: Caffeine for endurance performance: a practical protocol. Practical steps, who it helps, and what to watch out for.
Time to exhaustion research for endurance athletes
A lab outcome that can still guide training: it often tracks fatigue resistance.
Time-trial performance research for endurance athletes
Practical performance outcome used in many studies: closer to racing than lab-only metrics.