Carl Sagan’s quote, “The absence of evidence is not the evidence of absence,” applies intriguingly to fitness and nutrition, especially when evaluating trends, advice, or claims. Here’s how it plays out:

 

1. Nutrition Fads and Superfoods

Just because a particular food or supplement doesn’t have robust scientific evidence supporting its health benefits yet doesn’t mean it’s ineffective. Science takes time to catch up, and many traditional diets or foods may have real benefits that just haven’t been studied extensively. However, the reverse also applies—claims without evidence (like detox teas) shouldn’t automatically be trusted just because studies are absent.

 

2. Training Methods

Many unconventional training techniques or equipment might not have significant scientific backing but could still be effective. For example, Iranian Meels and Indian Maces or hybrid training styles that I like to program in for some of my clients and use myself, may not be mainstream but could offer real benefits. Similarly, the absence of evidence doesn’t mean they’re ineffective—it just means research hasn’t caught up.

“The absence of evidence is not the evidence of absence”

3. Injury Prevention

With sports therapy, the lack of evidence for a particular method (like certain types of stretching or rehab exercises) doesn’t mean it won’t work. It highlights the importance of personal experimentation and individual responsiveness. However you I’m still not buying cupping.

4. Individual Variability

Some people dismiss specific training programs or diets because evidence in broad populations is limited. But the absence of evidence doesn’t negate that it could work for someone. Fitness and nutrition are highly individualised, and what works for one person might not yet have enough documented evidence to generalise.

In the fitness world, it’s about balance—remaining open-minded to new ideas while critically evaluating them, especially when strong evidence is absent. It’s the intersection of science, experience, and adaptability that builds a smarter approach to health.