Over the last few years a number of studies have looked at the importance of timing for nutrient intake. A number of studies have looked at the timing of carbohydrate intake and recovery from intense exercise. Others have looked at timing of carbohydrate intake and performance. And of carbohydrate intake and recovery. At least two research groups are now working on the effect of protein intake on protein synthesis while people are asleep. This is important because:
- The greatest amount of growth hormone circulates while we are asleep
- A lot of muscle repair happens while we are sleep
- The muscle repair or building boost that happens when people ingest protein right after a workout does not last through the night when growth hormone levels are highest.
A group of researchers from the UK and the Netherlands investigated the effect of protein consumption just before sleep and the rate of protein synthesis.
Protein intake and exercise study protocol (very brief)
- Two groups of eight recreational athletes (All young men. Total = 16)
- Subjects did leg extensions and leg presses at weights close to each individual’s limit of ability
- All subjects received same diet during the study
- 8 were given 40 grams of protein just before bed. Eight were not.
- Muscle biopsies were taken at the time of protein intake, and 7.5 hours later. After sleeping.
Protein intake and exercise study results
Rate of protein synthesis was higher in subjects who received protein just before sleeping. This is an important finding because:
- It confirms that protein ingested just before sleep is digested and used to make muscle in humans.
- Throws doubt on that old adage that you shouldn’t eat for several hours before bed
- Protein intake before bed may may mean faster recovery for athletes
- Protein intake before bed may help slow or prevent natural loss of strength and muscle mass in middle aged adults.
- Protein intake before bed may help the elderly avoid muscle wasting. This is a major factor limiting quality of life for the elderly.
Taking it to the next level
The second research group (Groen et al. 2012) also looked at the effect of night time protein intake on muscle synthesis. The gave a group of elderly men protein at night, directly to the stomach, while they were actually asleep. Protein synthesis increased in this group too. Few athletes, even devoted CrossFit men (or CrossFit women) will want to go to this extreme. You never know. It may be a very good news for elderly people with muscle wasting.
Res PT, Groen B, Pennings B, Beelen M, Wallis GA, Gijsen AP, Senden JM, & VAN Loon LJ (2012). Protein ingestion before sleep improves postexercise overnight recovery. Medicine and science in sports and exercise, 44 (8), 1560-9 PMID: 22330017
Groen BB, Res PT, Pennings B, Hertle E, Senden JM, Saris WH, & van Loon LJ (2012). Intragastric protein administration stimulates overnight muscle protein synthesis in elderly men. American journal of physiology. Endocrinology and metabolism, 302 (1) PMID: 21917635