Here's an excerpt of the published scientific article the two videos below, with Prof. Stu Phillips, discuss and refer to.
For the full article:
Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men
Nicholas A. Burd,Daniel W. D. West,Aaron W. Staples,Philip J. Atherton,Jeff M. Baker,Daniel R. Moore,Andrew M. Holwerda,Gianni Parise,Michael J. Rennie,Steven K. Baker,Stuart M. Phillips
Published: August 9, 2010DOI: 10.1371/journal.pone.0012033
We aimed to determine the effect of resistance exercise intensity (% 1 repetition maximum—1RM) and volume on muscle protein synthesis, anabolic signaling, and myogenic gene expression.
Fifteen men (21±1 years; BMI = 24.1±0.8 kg/m2) performed 4 sets of unilateral leg extension exercise at different exercise loads and/or volumes: 90% of repetition maximum (1RM) until volitional failure (90FAIL), 30% 1RM work-matched to 90%FAIL (30WM), or 30% 1RM performed until volitional failure (30FAIL). Infusion of [ring-13C6] phenylalanine with biopsies was used to measure rates of mixed (MIX), myofibrillar (MYO), and sarcoplasmic (SARC) protein synthesis at rest, and 4 h and 24 h after exercise. Exercise at 30WM induced a significant increase above rest in MIX (121%) and MYO (87%) protein synthesis at 4 h post-exercise and but at 24 h in the MIX only. The increase in the rate of protein synthesis in MIX and MYO at 4 h post-exercise with 90FAIL and 30FAIL was greater than 30WM, with no difference between these conditions; however, MYO remained elevated (199%) above rest at 24 h only in 30FAIL.
These results suggest that low-load high volume resistance exercise is more effective in inducing acute muscle anabolism than high-load low volume or work matched resistance exercise modes.
In conclusion, we have demonstrated that low-load high volume resistance exercise has a potent stimulatory effect on anabolic signalling molecules, MyoD and myogenin mRNA expression and muscle protein synthesis. Our results support previous findings that demonstrated after 16 weeks of isometric training at 30% maximal voluntary contraction that significant increases in fibre area can be achieved . Although, the contraction type employed in the current study (i.e., dynamic) differed from Alway and colleagues  (i.e., isometic), our data provides further support that low-load contractions performed with numerous repetitions or high-load contractions performed for fewer repetitions will result in similar training induced gains in muscle hypertrophy as previously suggested , or even superior gains, as results from the current study would predict. This premise is further supported by data which demonstrates that short-term changes in muscle protein synthesis ,  are predictive of training induced gains in muscle mass , ; however, a training study in which these distinctly different exercise loads (90FAIL and 30FAIL) are utilized is clearly warranted to confirm our speculation.
For the full article: