Questions answered by:
SW: Shawn Wierick, MS, MBA
PhD Student in Exercise Science, University of Arkansas
WCA: Whitley Atkins, Ph.D.
Assistant Professor of Exercise Science, University of New Mexico
What is the most efficient way to train an endurance athlete 3 months prior to an event? (i.e. marathon, ultramarathon, triathlon, etc.)? Volume training, HIIT, Resistance training, etc.? What’s the most efficient way to train?
SW: There is no single most efficient way to train all endurance athletes in the final three months before an event. Efficiency is highly individual and depends on factors such as training age, athlete history, event demands, current fitness, and recovery capacity. I would say the best approach is one that emphasizes specificity while preserving the athlete’s ability to adapt, typically a strong aerobic volume foundation complemented by carefully placed, event-relevant intensity. High-intensity and resistance training are tools, not solutions, and their value depends on how well the athlete can tolerate and recover from them at that stage.
Is a change in HRV status a sign of overreaching or is it a sign of overtraining?
SW: A single change in HRV is not diagnostic of overtraining and, by itself, does not distinguish overreaching from overtraining. When HRV alterations are persistent, accompanied by performance decline and multisystem symptoms over time, does concern shift toward overtraining. The context and time course are essential.
How can we know we are overtraining?
SW: I would start to consider overtraining when performance keeps dropping despite backing off, and the athlete just doesn’t bounce back. It’s not one metric, it’s a pattern: persistent fatigue, higher effort for the same work, poor sleep or mood, and stalled or declined performance over weeks or more. If rest doesn’t restore performance, that’s the red flag.
Can you talk to how increasing simple carbohydrates immediately before a sporting event might decrease performance?
WCA: This only becomes an issue is the athlete has gastric issues that may cause upset. I think any major dietary change my cause upset depending on the individual, therefore, it is important to practice race-day or event-day fueling in training.
Pretty wild how carb intake during training and competition continues to increase, especially in events like ultra running, cycling and Ironman triathlon – have you noticed the improved type of bio-available carbs?
WCA: Sports nutrition continues to improve and therefore, I believe athletes are able to really push the upper limits of CHO consumption during exercise.
How do you feel measurement of allostatic load should be handled? Metrics and methods for endurance athletes.
SW: When we talk about allosteric load, or total stress burden over time on the body, we’re describing how training stress, recovery, sleep, nutrition, and life stress all add up. For endurance athletes, it’s best handled by looking at trends over time rather than any single metric, using both objective data (performance, HR, HRV, training load) and subjective feedback (fatigue, mood, sleep, perceived effort).
WCA: I think that if the athlete can tolerate it, then pushing the upper limit is warranted. We tend to see athletes handle 90-100g/CHO pretty well but beyond that it depends on the individual and there is a trade-off between CHO consumption and avoiding gastric upset.
What physiological markers best predict endurance success today—and which are overrated?
SW: Physiological markers like VO2max, lactate threshold, and economy are all important and tend to set the ceiling for endurance performance. Where things get overrated is relying on any single number in isolation. What ultimately predicts success is how these traits come together to support sustainable pace, durability, and consistency over time, not one metric by itself.
Do you think VO₂ max still matters as much as we think it does in the age of data‑driven training and real‑time metrics?
SW: Yes, VO2max still matters because it helps define an athlete’s aerobic ceiling, and at higher levels of performance there’s a minimum capacity you need to be competitive. What’s changed is that now we rely less on VO2max alone and more on how that capacity is expressed in real time, through sustainable pace, efficiency, and durability in training and racing. Data driven tools help us see performance more clearly, nbut they don’t replace the underlying physiology.
Where is the line between productive training stress and damaging overload?
SW: I don’t think there is a sharp line, it’s more of a moving boundary that depends on each individual athlete. Productive stress leads to fatigue followed by adaptation, while damaging overload is when fatigue accumulates and recovery no longer restores performance. The moment stress stops producing a rebound and starts producing stagnation or decline, you’ve crossed the line.
In pushing limits, what early warning signs should endurance athletes take more seriously?
WCA: frequent illnesses, lingering fatigue, and an often-overlooked symptom I see in my athlete’s is irritability. If I can sense building frustrations or short-tempers, I will decrease volume. This is more anecdotal than scientific to be honest.
How should athletes adapt training as they age, especially those pursuing long careers in endurance sports?
WCA: Strength training is important and often overlooked in the world of endurance training. For a long-career in endurance sports, strength training is key as we want to be resilence.
What’s a commonly ignored recovery practice that you consider non‑negotiable?
WCA: Not sure that it is ignored but sleep is a non-negotiable.
What are the most persistent myths in endurance nutrition?
SW: One of the most persistent myths in endurance nutrition is that there’s a single “optimal” diet that works for every athlete. Fueling needs are highly individual and depend on things like training load, body composition, gut tolerance, and performance goals. Other common myths are that supplements can compensate for poor fueling or recovery, or that being lighter automatically improves performance, effective endurance nutrition is about availability, timing, and consistency, not rigid rules.
How should fueling strategies differ for men vs. women, or for amateurs vs. elites?
WCA: I don’t believe that there should be a significant differences in fueling strategies. Everyone, regardless of level, should prioritize nutrition in and outside of training. Those (maybe elites) with significant greater training volume will need more calories.
