Does fasted training lead to less gains?
Overview
- What did they test? Researchers tested the effect of completing two weekly resistance training sessions, either after a 10-12 hour overnight fast or 1-2 hours after the ingestion of a carbohydrate-rich meal, on muscle hypertrophy, strength, and power.
- What did they find? Participants in both groups improved muscle strength and power, and there was no difference in outcomes between groups based on the timing of eating relative to resistance training.
- What does it mean for you? Proper preworkout nutrition can improve resistance exercise performance. However for many people, including those who exercise first thing in the morning, eating a meal before training may not be feasible.
This study showed that performing resistance training after a 10-12 hour overnight fast did not negatively impact hypertrophy or performance outcomes over 12 weeks. This suggests that the impact of appropriate preworkout fueling on training may be less impactful than what we have previously thought.
What’s The Problem?
Consuming a carbohydrate-containing meal before resistance training has been shown to improve performance, particularly during training longer sessions and for participants fasting >8 hours before training 1. However, it is unclear if this reduction in performance from inadequate preworkout nutrition is significant enough to impact hypertrophy or strength outcomes.
Previous studies that have examined this question have not shown differences in outcomes among participants who train in the fasted vs. fed state 2 3. But these studies primarily used participants who were fasting during Ramadan, which includes other activities related to the religious practice. These studies also did not have a dietary control, which is important due to the impact of energy and protein intake on adaptations to resistance training.
Many people perform resistance training in the fasted state due to schedule and convenience, and while we know this can impact exercise performance, it is currently unclear if this has a deleterious effect on hypertrophy and performance adaptations over time, particularly when dietary intake is controlled.
Purpose
Training in the fasted state has been shown to negatively impact exercise performance, but it is unclear if this translates to less hypertrophy and strength adaptations to a resistance training program over time. Therefore, the purpose of this study was to examine the effect of training after an overnight fast vs. 1-2 hours after eating a meal on hypertrophy, strength, and power outcomes from a 12-week resistance training program.
Hypothesis
The researchers hypothesized that hypertrophy, strength, and power increases would be smaller in the group that trained fasted vs. those who trained after eating.
