Q&A #82 - Minimum worthwhile time for a workout; Two hard workouts on the same day What is the minimum duration a workout (particularly a bike) should be to be worthwhile? Is deliberate planning of two hard workouts on the same day (e.g. "double-threshold") an effective strategy to get a stronger training response?    LINKS AND RESOURCES: That Triathlon Show website  Coaching Training Plans PGC-1β is downregulated by training in human skeletal muscle: no effect of training twice every second day vs. once daily on expression of the PGC-1 family Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens Twice-a-day training improves mitochondrial efficiency, but not mitochondrial biogenesis, compared with once-daily training Exercise twice-a-day potentiates markers of mitochondrial biogenesis in men Post‐exercise carbohydrate and energy availability induce independent effects on skeletal muscle cell signalling and bone turnover: implications for training adaptation   SPONSORS: Precision Hydration - One-size doesn't fit all when it comes to hydration. Take Precision Hydration's FREE sweat test and learn how you should hydrate. Use the discount code THATTRIATHLONSHOW15 to get 15% off your order OR use the code THATTRIATHLONSHOW and get your first box for free.   ROKA - The finest triathlon wetsuits, apparel, equipment, and eyewear on the planet. Trusted by Javier Gómez, Gwen Jorgensen, Flora Duffy, Mario Mola, Lucy Charles and others. Visit roka.com/tts for 20% off your order.   RATE AND REVIEW: If you enjoy the show, please help me out by subscribing, rating and reviewing.    CONTACT: Want to send feedback, questions or just chat? Email me at mikael@scientifictriathlon.com or connect on Instagram, Facebook, or Twitter.