Tough crowd: Whey protein, vitamin D could increase muscle mass in athletic males – RCT
According to a recent study, consuming the two before or after sleep resulted in similar benefits without any adverse effects.
“Resistance training in combination with dietary protein supplementation has been promoted as an effective approach to stimulate muscle protein synthesis, which is associated with muscle hypertrophy and elevated muscle strength.
“Dietary protein recommendations are typically presented in 24-hour units, but it has become increasingly clear that the distribution of protein within each 24-hour period is a critically important factor for sustaining and/or increasing musculature,” said the researchers.
Therefore, they devised an RCT to examine the effectiveness of whey protein and vitamin D3 supplementation on muscles in young males performing resistance training. Subsequently, the team investigated the differential outcomes based on the consumption times.
Results from 42 subjects aged 18 to 24 years old in Beijing were measured and analysed from November to December 2021. They were divided into three – one group consumed the supplementation before bedtime, the second group after sleeping and the last was the control.
The intervention groups were given 25g of whey protein and 4,000 IUs of vitamin D3, while the control group was given a 5g maltodextrin placebo. They underwent a resistance training programme too.
Throughout the six-week intervention period, the scientists recorded a significant increase in serum vitamin D and the thickness, circumference and cross-sectional area of the rectus femoris muscle for the intervention groups.
Additionally, all groups experienced a significant gain in leg press, but the control did not experience it significantly.
The changes in blood hormone markers related to muscle health were consistent with changes in muscle mass and other body composition-related changes found in the intervention groups. Furthermore, muscle strength assessed by knee extension significantly increased in these two groups.
All subjects were documented to have consumed sufficient protein, and there was no difference between groups. The ‘before bedtime’ group consumed supplements before sleep, which could be considered adding a protein-enriched meal before sleep, resulting in a shorter fasting time between meals than the other two groups.
Therefore, an improved meal frequency could have contributed to an enhancement of muscle protein synthesis. Hence, consuming supplements either before bedtime or in the morning resulted in positive effects on muscle health.
Overall, the consumption of whey protein and vitamin D3 supplements combined with resistance training in healthy young males spanning six weeks showed beneficial effects on muscle mass and strength.
Data also suggest that undergoing a resistance training programme with a non-nutrient placebo might achieve a moderate elevation in muscle strength but without an elevation in muscle mass.
This research was funded by the National Key R&D Program of China and the Herbalife Winter Sports Development Fund.
“Muscle-Related Effect of Whey Protein and Vitamin D3 Supplementation Provided before or after Bedtime in Males Undergoing Resistance Training”
Authors: Chen Yan et al.