Training in the late afternoon or evening is ideal because studies have shown strength to be higher later in the day. In addition, training later in the day allows you to plan your pre-workout nutrition more easily and ensure you have plenty of fuel in the tank before training.
PROSECUTION
Although it is true that strength tends to be lower in the morning when you are unaccustomed to lifting early in the day, with time, this strength deficit goes away. Furthermore, lifting early in the day allows you to get in more meals after your workout when anabolic signaling is high.
EVIDENCE
Studies comparing the effects of training times for untrained lifters indicate that, at least in the short term (less than 12 weeks), equal gains in size and strength can be achieved.
Working out regularly in the morning for at least five weeks can reduce morning– afternoon difference in strength, whereas regular afternoon training amplifies the morning–afternoon difference.
A recent study was able to show that training in the morning led to an 8.8% increase in muscle fiber cross-sectional area, whereas training in the afternoon produced an 11.9% increase. However, this difference was not statistically significant.
One study to date has been published indicating that it may be more beneficial to train in the afternoon if training goes beyond 12 weeks. This study used untrained subjects and combined strength and endurance training together, which makes it difficult to apply strictly to bodybuilding training.
VERDICT
The bulk of the evidence shows that your gains should be similar whether you train in the morning or afternoon.
SENTENCING
Train when you feel motivated and your schedule allows. Consistency plays a much bigger role in determining gains.
