I've been reading up on intermittent fasting and I've been trying to figure out if its a plausible option for me. I have a pretty small frame and my goals aren't necessarily to lose weight but more so to gain lean muscle mass. I am 22 5'4" and I weigh 108. I Crossfit about 4-5x a week and have been following paleo for about 6 months now.
I just can't seem to wrap my brain around not eating for an entire day or only eating one meal as a healthy idea for me. Can someone break it down so that I can understand how this would help me reach my goals. I am very interested to know more. . .
Robb Wolf has mentioned in his podcasts, on a couple of occasions, that adding IF to an already stressful workout regimen can be somewhat detrimental. Someone correct me if I'm wrong, but I believe this is the take home message: more stress leads to higher cortisol production, and higher cortisol levels leads to more catabolism, hence, loss of lean body mass.
That said, I highly, -highly- recommend Martin Berkhan's site (www.leangains.com) for info on IF in regards to adding lean mass. His client results are nothing short of amazing, and they all follow 8/16 feed/fast protocol. From what I understand, much of them do little to no cardio at all.
If you have been training for some time, It's generally regarded as a truism that you need to have a caloric surplus above your daily expenditure to gain lean mass, so any cardio, met-con, etc. that puts you in a caloric deficit won't do you any good for adding lean mass.
For your body build and type, it makes sense to tinker with IF for the other documented benefits (insulin sensitivity, longevity, fasted workouts, and the host of other hormonal/endicrinological benefits).
But if you are looking to gain muscle mass, I'd just concentrate on really cleaning up the food quality, increase calries, and maybe dial down the crossft? 4-5 dys of crossfit is alot for tryin to ADD mass.
I'd agree with Danny and LiveForIt's answers - and just add that IF can release HGH, so IF'ing a couple of times a week, but maintaining calorie levels (probably by two big meals in a short time window of say 4 - 6 hours), may assist you in adding mass. I also agree that CF 4 or 5 times a week is too much, it doesn't sound like sufficient recovery. Fewer, more intense sessions, would probably assist you in adding mass.
I think it's fine, but when your activity levels are high, eat more
alot of people use IF for weight loss, where they don't replace the calories they skip
you can gain the hormonal advantage of IF without weightloss by replacing the calories
personally when I'm not trying to drop the vanity pound back off, I will train fasted, then eat big after, if I get soft, I don't eat heavy after...
IF for gaining lean mass is about collapsing your primary eating window into a 6-8 hour eating window following your workout. Martin's ideas at leangains.com have heavily influenced how I eat.
For example, today I worked out around 8pm, then over the next 5 hours or so ate:
I was hungry this morning after playing a little basketball, so I also ate 2 eggs, 3 strips bacon and small sourdough roll with goat cheese (~700 kcal)
I am 6' and a lean 176 pounds, and this is a very satiating amount of food for me. I run or play basketball most days of the week and do a 20 minute chin/dip/squat & sandbag workout as well most days. I have not experienced any stress or cortisol issues that Robb Wolf may have mentioned in his podcasts.
I've found it pretty easy to gain lean mass on this sort of protocol if I
Regarding fat consumption, Volek and Kraemer have a good read Testosterone and cortisol in relationship to dietary nutrients and resistance exercise.
The sample size is small, but the 4 subjects with the highest testosterone (22-24 nmol/L) consume far more fat and less protein than the 7 subjects with moderate testosterone (12-17 nmol/L). See Table 3