Which supplement works better to improve running performance: iron or sodium?

Ratings at a Glance

Supplement	Effectiveness Rating	Confidence Rating
Iron
Sodium

Effectiveness Rating: Iron vs Sodium

The effectiveness rating is a measure of the supplements' ability to improve running performance. This rating answers the question of whether or not a supplement does what it claims. The evidence backing up iron to improve running performance is much better than the evidence backing up sodium. Iron should provide positive results while sodium will not.

Confidence Rating: Iron vs Sodium

Another factor to take into account when comparing supplements is the confidence rating. This rating is a measure of how valid each supplement's effectiveness rating is. Remember, the confidence rating is a measure of how much you can trust the effectiveness rating. This rating is based on how many studies are included in the database on a supplement's claims. Ideally, you want a high effectiveness AND confidence rating.

Sodium's confidence rating is higher than iron's. This means sodium's effectiveness rating from above is more valid. This does not necessarily mean that sodium works better, it simply means the evidence (included in this database) backing up sodium is more established.