Question: Should I continue with around workout nutrition while dieting?
Answer: Since summer time is approach and everyone (more or less) is dieting to look good at the pool, this is a question that comes up fairly often. I’ll be honest that I spent years going around and around with this one in my head before finally coming to some conclusions about it. These are those conclusions.
The usual rationale for avoiding around workout nutrition while dieting goes something like this: if you consume nutrients (especially carbohydrate) during or after training, you will either impair fat mobilization/burning by increasing insulin levels or impair the hormonal response (growth hormone gets brought up a lot) and slow fat loss. Some suggest only consuming protein around training for this reason although they all seem to forget that protein (and especially the Branched Chain Amino Acids) raise insulin.
A related idea is of doing training first thing in the morning fasted to take maximum advantage of the increase in blood fatty acids which occur during the overnight fast. And certainly, for certain types of activity (especially low intensity aerobic activity), there is certain some truth to this. Of course, those types of activities don’t generally require much in the way of around workout nutrition in the first place.
Certainly this strategy has been used for decades by contest prepping bodybuilders or other athletes who need to lean out. As I discuss in detail in The Stubborn Fat Solution, for individuals looking to shed the last bit of stubborn fat, there is probably some rationale to this strategy due to the profound impact of insulin on fat mobilization. Of course, for people who can’t work out first thing in the morning or fasted, there are also ways to get around that (discussed in the book) and still deal with stubborn fat.
But what about higher intensity activities such as weight training or more intense types of metabolic work, should around workout nutrition still be maintained (to at least some degree) while dieting?
The short-answer, in my opinion, is yes. Here’s the longer answer.
First let’s look at metabolic work, cardio and interval type work. For the most part, concerns about impairing fat oxidation during higher intensity activity with the consumption of during workout nutrition don’t seem to be warranted in the first place.
As Alan Aragon reviews in his book Girth Control, research clearly shows that the consumption of carbs during moderate and higher intensity aerobic activity doesn’t negatively impact fat oxidation in the first place. Basically, it’s only low intensity aerobic activity where this is an issue and, as noted above, that type of training doesn’t require much in the way of nutritional support in the first place.
I’d even go further and argue that proper during workout nutrition during higher intensity activities can help with fat loss simply because it tends to improve intensity and performance, allowing people to work harder and/or longer which burns more calories which is far more important in the big scheme of fat loss.
Trying to perform higher intensity training when blood sugar is down often goes badly (there is a lot of individual variability in this). From a fat loss standpoint, I consider being able to train effectively far more important than any small benefits from a hormonal or other perspective.
Of course, I’d make the same argument for weight training (with the exception of activities done specifically to deplete muscle glycogen); the ability to maintain training intensity in the weight room (which is the key to maintaining muscle mass) is far more important in the big scheme of things than any small hormonal effect or what have you. As well, weight training doesn’t generally use fat for fuel to any great degree in the first place. Worrying about ‘impairing fat burning’ during weight training sessions is missing the point.
It’s also worth noting that much of the concern over post-workout nutrition under these conditions may be equally misplaced. It’s usually feared that consuming carbs after a workout will impair any post-workout fat burn (I’d note that any effect from this is very small in the first place).
However, research shows that following high-intensity (aerobic) activity, the body continues to use fat for fuel even when carbs are consumed immediately after workout; under those conditions the carbs go to refill glycogen stores but the body continues to use fat for energy production.
And given that proper post-workout nutrition is one of the key aspects to improving overall recovery (always at a premium when folks are dieting), I think that the benefits of maintaining at least some around workout nutrition outweigh any slight negatives in the case.
Finally, there is also the often forgotten fact that most of the ‘fat burning’ that happens during a diet doesn’t occur during training (especially weight training) in the first place. Rather, it’s what happens the other 23 hours of the day that will have the biggest impact on overall fat loss. And that’s mostly related to diet.
Don’t get me wrong, exercise clearly contributes to fat loss through a variety of mechanisms but, again, it’s less the hour you spent training and what happens in the other 23 hours of the day that will maximally affect fat loss.
Basically, at least if you’re talking about moderate to high-intensity types of training, I think the benefits of around workout nutrition far outweigh any of the negatives. During workout nutrition can help to maintain training intensity and proper post-workout nutrition improves recovery. I think those benefits far outweigh any small or nonexistent negatives that might occur.
Basically, rather than cut carbs/protein from around hard training sessions, I’d rather see those cuts (especially carbohdyrates) coming from other meals of the day. Some dieters will actually take this to the extreme of only consuming carbohydrates around training and eating no starchy carbs the rest of the day.
This is essentially the Targeted Ketogenic Diet (TKD) that I discussed in my first book The Ketogenic Diet and it can provide any benefits of a full-blown low-carbohydrate diet while still allowing trainees to maintain training intensity and recovery from high-intensity worouts.
However, that may not be desired or required for all dieters. Some people do poorly on low-carbohdyrate diets and will need to consume some carbs at other meals of the day in addition to any around training nutrition. This means that, in most cases, the amount of around workout nutrition consumed may have to be scaled back somewhat.
Someone consuming a lot of calories around training may leave themselves with almost nothing to eat the rest of the day on a diet and scaling the values back may be necessary. I can’t give recommendations beyond that since a lot will depend on how much is being consumed around training in the first place.
A trainee consuming a very large amount of carbs and protein post-workout (e.g. 100 grams carbs/40 grams protein) might cut that in half while dieting; someone consuming a small amount in the first place (e.g. 20-30 grams of each) might not cut back anything at all.
Of course, I also think that training volume (especially in the weight room) should be reduced while dieting in the first place which means less requirement for around workout nutrition in the first place. But talking about weight training on a diet is another topic for another day.
But I don’t think that around workout nutrition should be eliminated while dieting completely, especially for moderate to high-intensity training sessions. The benefits from being able to maintain training intensity and recovery far outweigh any small benefits from the hormonal response or what have you (especially given that most fat loss happens outside of the gym anyhow).