An interesting study was published recently that confirmed a practice that few athletes are following today but may become more common in the future. I discussed the results of the paper published in the Journal of Nutrition in a recent blog: The study showed that protein ingestion before sleep resulted in greater increased in muscle circumference and strength. Dr Tim Snijders, the first author of the study agreed to do a little interview for us, to talk about some of the practical implications and things we cannot read in the paper. I have known Tim for a while as a young and very successful researcher and have seen him scoop up various awards at conferences.
Thank you Tim for participating in the interview. I want to talk a little bit about you, about the study and mostly about the practical implications and next steps.
Asker: Lets start with you. You are Dutch, have done your PhD in the lab of Prof van Loon in Maastricht (The Netherlands), the same University where I received my PhD many years ago. As many readers will know Prof van Loon is one of the world leading experts in the area of protein metabolism. Now you are at McMaster University in Hamilton Canada working with two other big names in this field: Dr Gianni Parise and Prof Stuart Phillips. Can you tell us a little bit what motivated you to become a researcher in this field and what work you have done so far?
Tim: My main motivation for becoming a researcher in the field of exercise physiology is mostly personally driven by the questions how muscle is able to adapt in response to different stimuli, like exercise. I find it extraordinary how skeletal muscle is able to adapt to the sometimes extreme demands of exercise training and/or physical performance. Furthermore, understanding the triggers and underlying mechanisms of muscle fiber adaptation will help to further optimize existing and/or develop new exercise and nutritional intervention strategies to combat muscle wasting disorder like sarcopenia and cancer cachexia.
During my PhD I mainly investigated the importance of skeletal muscle stem cells during muscle fiber adaptation in response to nutrition, exercise and aging. In a series of experimental human studies we were able to show that the reduced function of muscle stem cell in response to exercise may be an important factor in the loss of muscle mass with aging. In addition, this reduction in muscle stem cell function may be key in the reduced capacity for seniors to increase skeletal muscle mass and strength during prolonged resistance type exercise training. As a post-doctoral fellow at McMaster University I am continuing my research to further optimize existing nutritional and exercise training intervention strategies to more effectively combat the loss of muscle mass with aging.
Asker: Your recently published study built on the Peter Res’ study in which it was found that ingesting 30g of protein before sleep had a positive effect on protein synthesis. What is new in this recently published study?
Tim: In the previous study from Res et al. (2012) our laboratory has shown that protein ingestion prior to sleep resulted in a significantly greater muscle protein synthetic response during overnight recovery when compared to a placebo drink. However, whether the acute changes in the muscle protein synthetic response would also translate to a greater increase in skeletal muscle mass and/or strength following prolonged resistance type exercise training remained to be established. In the present study we were able to show, for the first time, that protein ingestion immediately prior to sleep has an additional beneficial effect on the increase in skeletal muscle and strength during 12 weeks (3 x pw) resistance type exercise training in young men. We found it quite remarkable to observe that protein ingestion prior to sleep effectively increased the gains in muscle mass and strength despite the fact that these healthy young men already consumed a relative high protein diet (1.3 g of protein per kilogram bodyweight per day).
Asker: A few people commented on the fact that total protein intake was not controlled in your study. Can you attribute the effect to the time of intake (before sleep) or is it a matter of total protein intake?
Tim: Before the start of the intervention no difference was observed in habitual protein intake between the two groups. However, total protein intake was significantly higher in the protein supplemented group throughout the intervention period. This difference in protein intake can entirely be attributed to the protein supplement provided in the protein supplemented group. In the placebo supplemented group, average protein intake did not change in response to the intervention program. As such, the greater increase in skeletal muscle mass and strength in the protein supplemented group is most likely due to the fact that more protein is being consumed in this group and not necessarily the timing of the consumption. This study shows that protein ingestion augments the increase in skeletal muscle mass and strength during resistance type exercise training. In addition, it shows that prior to sleep appears to be an effective time point to ingest that protein supplement. In other words, from this study we cannot conclude that protein ingestion prior to sleep is more effective than other time points during the day to augment the increase in muscle mass during exercise training.
Continue to PART 2 of this interview