In this episode of MASS Office Hours Live, Dr. Eric Trexler and special guest Dr. Mike Zourdos celebrate the 7th anniversary of MASS by walking viewers through a new (free) training guide on time-efficient upper body training techniques, including rest-pause sets, supersets, and drop sets. Trexler then delves into a thorough discussion of weight loss mechanisms, the role of calorie balance, the importance of overall dietary patterns, and how the gut microbiome may impact energy extraction from food. Eric and Mike proceed to answer a variety of listener questions from the live chat, covering topics such as the use of appendicular lean mass in DEXA scans, optimal fruit and vegetable intake, the protein leverage hypothesis and obesity, physiological differences between cycling and running, the impact of pre-game rituals on performance and psychological readiness, the viability of powerbuilding as a long-term training approach, and the distinction between work capacity and conditioning. Throughout the episode, Trexler and Zourdos provide evidence-based insights and practical applications for fitness enthusiasts and professionals alike. You can download the free time-efficient training guide here: https://massresearchreview.com/ The MASS crew goes live for Office Hours every Wednesday night at 7pm eastern time. Be sure to join us for a future episode!  If you'd like to submit a question ahead of time, please use this link:  https://massresearchreview.com/office-hours/ Time stamps: 0:00 - Intro 3:17 - Zourdos walks through the new free MASS training guide on time-efficient training techniques for the upper body, including rest-pause sets, supersets, and drop sets 17:06 - Trexler answers a listener question about core mechanisms of weight loss, different diets and foods, and exercise - discusses calorie balance, energy density of foods, importance of overall dietary patterns, and research on how the gut microbiome may impact energy extraction from food 37:24 - Q&A from the live chat begins 39:38 - Question about using only appendicular lean mass from DEXA scans to assess lean mass changes 45:03 - Question about fruit and vegetable intake - how much is optimal and when do benefits plateau? 51:07 - Question about the protein leverage hypothesis as an explanation for the obesity epidemic 57:05 - Question about optimal carbohydrate intake for lifters 58:37 - Question about environmentally sustainable diets 1:01:46 - Question about performance and physiological differences between cycling and running 1:04:04 - Question about the impact of pre-lift/pre-game rituals and routines on performance and psychological readiness 1:16:07 - Question about powerbuilding as a long-term training approach vs periodized strength and hypertrophy blocks 1:19:39 - Question about the difference between work capacity and conditioning