I agree, the research on testosterone responses to weight training is somewhat conflicting. Some research studies report an increase in circulating testosterone in response to a workout, others report a marked decline in the hours after training.
One of the reasons for the discrepancies has to do with the research protocols used.
For example, in studies where food or supplements are not consumed after training, circulating testosterone levels are shown to increase. However, in studies where macro-nutrients (protein and carbohydrates) are consumed after the workout, a consistent decline in circulating testosterone has been observed.
Decline? That doesn’t seem right does it? Don’t be concerned, this is actually a good thing in terms of muscle growth and I’ll explain why.
Most bodybuilders know they need protein and carbs after a workout. These important macro-nutrients provide a dramatic increase in muscle protein synthesis and a positive net gain in muscle mass.
One of the main reasons for this increase in protein synthesis is thought to be because of the increased uptake of testosterone by muscle to facilitate this process. Although weight lifting triggers an increase in testosterone production, a decrease in blood testosterone levels in response to nutrient-timing after a workout is due to the increased uptake of this hormone by muscle.
The important presence of protein and carbs in the blood stream triggers an insulin response that is thought to facilitate the uptake of testosterone by muscle tissue..
This theory is supported by studies that show a decline in circulating testosterone in response to meal consumption after a workout is not linked to a decrease in lutenizing hormone production. Lutenizing hormone is responsible for testosterone production.
Other scientists have reported that a meal-induced decrease in post-workout circulating testosterone corresponded with an increase in muscle androgen receptor content.
The link between diet, training and the hormonal cascade that results in muscle growth remains elusive. I’ll keep you up-dated as research sheds more light on this complex topic.
