When to take supplements for peak performance?

Summary: The article highlights new research on the optimal timing for taking various performance-enhancing supplements. The key question is whether timing matters—and if so, how much—for common supplements like caffeine, nitrate, creatine, bicarbonate, beta-alanine, iron, and calcium. By distinguishing between short-term and long-term effects, it becomes evident that some supplements need careful planning before sessions and competitions, while others are focused on building up levels over time. The conclusion is that timing can be crucial for some supplements but less relevant for others—and that the optimal strategy depends on both the supplement's mechanism of action and the level of training.

Introduction

A review article (full text) titled “Timing of ergogenic aids and micronutrients on muscle and exercise performance” has just been released, focusing on WHEN to take specific performance-enhancing supplements. We have previously discussed several of these supplements in articles about their usage and appropriate dosage. That aspect feels covered—now we focus on timing.

Caffeine

We've previously written about caffeine here, and how different forms of caffeine products differ in effect here. A recommended ergogenic dose for a notable performance-enhancing effect is 3–6 mg of caffeine per kilogram of body weight for most individuals.

Caffeine enters the bloodstream within 5–15 minutes and reaches its peak after 40–80 min (average around 60 minutes) when consumed as powder, pills, or capsules. Caffeine gum provides a slightly faster effect due to quicker absorption through the mucous membranes in the mouth. In a study from 2002, researchers demonstrated that consuming 100–200 mg of caffeine peaked after 60 minutes with gum compared to 100 minutes for a capsule. The impact on performance was the same regardless of the method of administration, but gum reached the maximum effect a bit quicker—useful if you often miss your timing before interval sessions and want the impact from the start.

So far, all studies on the timing of caffeine intake have been conducted using test cycles. In a study by Bell & McLellan, participants received 5 mg of caffeine/kg body weight 1, 3, and 6 hours before performance. Results showed performance improvements when caffeine was taken 1 and 3 hours prior, but not at 6 hours before.

Interpretation: If you take caffeine about 1 hour before starting, you can expect effects during the first 1–3 hours of the activity, but not much longer. Caffeine has a half-life of about 3–5 hours (a rough memory rule is about 3 hours during activity and 5 hours while resting). If you take 250 mg of caffeine 60 minutes before activity, about 125 mg remains after 3 hours and 62.5 mg after 6 hours. Therefore, you might need to top up with a new dose during longer activities, or take small doses at regular intervals. In the example above, the body consumes about 125 mg in three hours, which corresponds to about 40 mg/h—taking 30–50 mg of caffeine per hour via pills, caffeine gel, or similar might be wise if you're going for an extended duration.

Nitrate

Nitrate has been a hot topic in recent years (many questions in the podcast). See also our article about nitrate in the form of beetroot juice and our article on dietary supplement guidelines.

Several intake variations have been tested. For most, intake of about 8 mmol (500 mg nitrate) 2–3 hours before activity is sufficient. The more well-trained and optimized your body is, the less absolute benefit you'll get from nitrate. For example, an amateur with less elastic blood vessels might experience a larger relative increase in vasodilation (say 20%), providing a performance boost of about 3%. An elite athlete with well-optimized vessels might only see a 5% larger diameter, leading to about a 1% performance boost—but that percent can be highly valuable.

More well-trained individuals might need to take nitrate over several days (3–7 days) to observe a measurable effect. The recommendation before a competition varies somewhat, but generally, an acute intake of about 500 mg nitrate 2–3 hours before the start is adequate for most, while very well-trained individuals (roughly those with VO2max over ~60 ml/kg/min) should load up over 3–7 days.

Creatine

We've covered creatine in a previous article here with a focus on how it enhances performance. Creatine is also discussed in articles about carbohydrate loading and optimal recovery, as creatine aids in faster glycogen store replenishment.

When it comes to timing, researchers compare three scenarios: intake before training, intake immediately after training, or intake during the day but not close to training. Studies on strength-training individuals suggest that intake immediately post-session is best. In comparisons where participants were equally strong, experienced, and trained with the same relative load, those who took 5 g of creatine immediately after the session experienced greater muscle mass increases than those who took it before.

In another study with less well-trained adults who took 0.1 g/kg body weight and trained three sessions per week for 32 weeks, intake directly before and after training was compared, along with a placebo. Creatine led to more muscle and strength compared to a placebo, but no difference in strength development was noted between the two creatine groups. However, only the group that took creatine after training saw a significant increase in muscle mass.

This might sound unclear: increased muscle volume often correlates with increased strength, but not always. The volume increase might partly stem from more glycogen storage when creatine is taken after the session—more volume without direct strength gain. In summary: if you're going to take creatine, take it post-session. It's at least as effective as other times and possibly slightly better.

Bicarbonate

We've explored bicarbonate in previous articles here and here. For timing, bicarbonate's role is crucial. Like caffeine, it has an acute effect and a time-limited breakdown period—plan your intake so the effect is maximum when you need it most.

Bicarbonate should be taken before intense sessions with work durations from about 30 seconds up to 20 minutes (think 30/14, 40/20, and threshold intervals). The dose is around 0.3 g/kg body weight, taken about 2.5 hours before activity. Researchers have compared intake 1, 2, and 3 hours before activity. Regardless of timing, participants saw similar performance improvements on repeated sprints, but the group that took bicarbonate 3 hours before reported the least stomach issues. With this in mind, we recommend taking bicarbonate 2–3 hours before activity, but test yourself to see what your gut can handle.

In one of our previous articles, we go through variations in how quickly bicarbonate peaks in the blood. Some reach maximum levels as early as 10 minutes, others only after 3 hours. The majority seem to be in the range of 2–3 hours, so let your gut dictate your planning.

Beta-Alanine

We don't have a longer article on Beta-Alanine yet, but we mention it in our article on supplement guidelines. Beta-Alanine doesn't provide an immediate performance boost. Instead, it builds up a buffer in the body (carnosine in muscles) that helps you better handle acidic conditions. The effects are most noticeable during more intense work bouts around 60 seconds (e.g., 30/14, 40/20 intervals).

The buffer takes time to build up. On average, the performance improvement is about 2.85% (exact number can vary between meta-analyses) with a total intake of 179 g. The recommended daily dose is 6–7 g divided into four doses (about 1.5–1.75 g per dose).

There is no clear guideline on the optimal time of day for intake — since the effect isn't acute, you don't need to plan intake around training sessions. The goal is to build the buffer over time.

A total intake of approximately 179 g of Beta-Alanine, taken in doses of 6 g/day, means it takes about a month to build up good levels in the body. Thereafter, the degradation rate is about 2% per week, so a maintenance dose of 3–5 g per week is recommended to maintain levels.

Iron

Iron is strongly linked to performance in endurance sports, but more isn't always better. Iron deficiency is directly harmful to your performance, but excess can also be negative. This has been discussed in a previous article.

With low hemoglobin levels, there are recommendations for 100 mg per day (for example, Niferex) for 3–6 weeks — but this should be discussed with your doctor. There is no approved research on optimal timing for iron intake in humans, but there are animal studies on mice. Mice were given iron immediately after training and 4 hours after training. The group that received iron immediately had higher levels of free iron in the blood — however, there was no difference in Hb later between the groups.

In summary: we know too little to dive deeply into exact timing. Iron is not an acute performance enhancer, so just like with Beta-Alanine, the most important thing is THAT it is taken if needed, not exactly when during the day.

Calcium

Calcium is undoubtedly one of the most important minerals discussed in this article. At the same time, it is not a performance enhancer in the traditional sense — with a varied diet, reserves are stored in the bones that can be mobilized as needed.

Calcium is essential: without calcium, muscles don't work, the heart beats, and you can't flex your biceps on the beach. Two very important things in life.

A well-studied factor is how calcium intake affects parathyroid hormone (PTH), which controls calcium management and bone building/breakdown. You might liken the skeleton to a bank vault full of calcium where PTH is the key that opens the vault.

Studies show that cyclists who primarily train in non-weight-bearing activities have an increased risk of osteoporosis, as the skeleton isn't stressed while calcium turnover is high. Intake of calcium-rich food before activity has been shown to keep PTH levels lower, which means the body doesn't "chew" as much on the bone reserves, thereby reducing the risk of osteoporosis in the long term.

Regarding timing, calcium intake (studies have tested 1 g calcium 15–60 minutes before activity) appears to have a beneficial effect to counteract osteoporosis in non-weight-bearing sports like cycling. Strength training and running, which stress the skeleton, strengthen bone density — so if you don't skip strength training, you might be fine anyway.

If you want to try calcium, the recommendation is 500–1000 mg of calcium carbonate or calcium citrate. Calcium carbonate should be taken with meals for better absorption, while calcium citrate has good absorption even without food and can be taken before training. See our previous article for images and details.

Summary

We'll let the images below speak for themselves — the researchers have summarized it all clearly (bring out the magnifying glass if it's hard to see).