[quote]smarterANDharder wrote:
EyeDentist, when you gave us one of your diet examples, you stated that your “carb window had closed” (my apologies for not including the quote). How big is your carb window exactly? Is this based on specific carb-cycle timing or just preference? And do you also have a cut off for ANY consumption, be it proteins, carbs, or fats?[/quote]
The thinking underlying the ‘carb window’ concept concerns the temporary, insulin-independent, exercise-induced upregulation of GLUT4 transporter complexes on the surfaces of muscle cells. That is, vigorous exercise produces a period of time during which the ability of muscle cells to import nutrients from the bloodstream is increased. This fact has led to the christening of this time-period as the ‘post workout carb window.’ Your question–and it is a good one–is, for how long post-w/o does the concentration of GLUT4 complexes remain elevated?
The short answer is, to my knowledge this subject hasn’t been addressed as of yet. (If anyone knows differently, please chime in.) For me, as a practical matter, my carb window is determined by how long it takes me to consume my carb allotment for the day. I always have a substantial carb meal immediately post-w/o, and will eat again not too long thereafter. I consume ~25 g carbs pre-w/o, and my first post-w/o meal contains ~125 g, so that’s ~150 g right off the bat. Lately my carb intake has been ~400 g, consumed over 6 hours or so post w/o. OTOH, if I were limiting myself to, say, 230 g (about as low as I would go), I’d probably finish them off within 2 hrs post-w/o.
So my advice in this regard is to determine a carb target for the day (rule of thumb: minimum carbs = BW-in-pounds + 50), and consume them post-w/o at whatever pace is most satisfying to you.
(An important caveat: A fairly recent literature review suggested that the post-w/o GLUT4 upregulation was not clinically meaningful; ie, feeding during this time did not result in significantly better results with respect to hypertrophy or strength. Stay tuned.)
Re timing of other macros: My rules of thumb (rule of thumbs?) are:
- In order to keep insulin low (thereby facilitating fat-burning), nosh sparingly on fat (= PB) as late into the day as possible
- Take a slug of fast-acting carbs + protein hydrolysates immediately pre-weightlifting (but not pre-cardio or conditioning!)
- Post-weightlifting, eat yummy carbs ad lib until the target for the day is reached
- Once the carb limit is reached, eat lean protein until the target for the day is reached
- On cardio/conditioning day, delay the switch from fats–>protein as long as is reasonably possible (eg, start consuming protein at dinnertime)
So nutritionally speaking, the day can be divided into three phases:
–The FAT phase commences upon awakening, and lasts as long as possible
–The CARB phase commences with weightlifting, and is fairly brief
–The PROTEIN phase commences upon completion of the carb phase, and lasts until the target is reached.
I don’t have a particular time-cutoff for eating, but usually stop eating about an hour or two prior to bedtime.