T Nation

Study: Spike Insulin Post-Workout?

Excerpted from the first issue of Alan Aragon’s Research Review:

Quote:
Is It Necessary to Spike Insulin Post-workout?

Another concern of the fat-free-post-workout camp is the blunting of the insulin response. The rationale of maximizing the insulin response is to counteract the catabolic nature of the post-trained state, switching the hormonal milieu into an anabolic one, thus speeding recovery. Although this might benefit those who train fasted or semi-fasted, many don�??t realize that a pre-exercise meal (and in some cases the mid-exercise meal) is doing more than enough spiking of insulin levels for anticatabolic purposes.

It�??s an important objective to not only maximize muscle protein synthesis, but also minimize protein breakdown. However, the latter doesn�??t require a massive insulin spike, but rather just a touch beyond basal/resting levels. To illustrate this, Rennie & colleagues found that even during a sustained high blood level of amino acids, no further inhibition of muscle protein breakdown occurred beyond insulin elevation to approximately 15 μU/l,20 which is slightly above normal basal levels of 5-10 μU/l.

To reiterate, the pre-exercise meal can have profound effects on insulin levels that surpass the length of the training bout. Tipton�??s team found that as little as 6g essential amino acids + 35g sucrose taken immediately before exercise (45-50 minutes of resistance training) was enough to keep insulin elevated to roughly 4x above fasting levels 1-hour post-exercise.21 It took 2 hours post-exercise for insulin to return to resting levels. A similar insulin response was seen with 20g whey by itself taken immediately preworkout.22 If carbs were added to the pre-training protein, there would be yet a greater insulin response.

As far as solid food goes, Capaldo�??s team examined various metabolic effects during a five hour period after ingesting a meal composed of 75g carb (47%), 37g prot (26%), and 17g fat (27%).23 Although this study didn�??t examine training effects, this meal would make a nice post-workout meal due to its absolute (and proportional) amounts of protein and carbohydrate. The fat-fearing camp would warn against the meal�??s fat content interfering with the insulin response. However, this meal was able to raise insulin 3 times above fasting levels within 30 minutes of consumption. At the 60 minute mark, insulin was 5 times greater than fasting. At the 300 minute mark, insulin levels were still double the fasting level.

Elliot and colleagues compared the effect of fat-free milk, whole milk, and a higher dose of fat-free milk (to match the calories of the whole milk) taken 60 minutes post-resistance exercise.24 Whole milk was superior for increasing net protein balance. Interestingly, the calorie-matched dose of fat free milk containing 14.5g protein, versus 8.0g in the whole milk (an 81% advantage), but still got beaten. The investigators speculated over the possible mechanisms behind the outcome (insulin response, blood flow, subject response differences, fat content improving nitrogen retention), but end up dismissing each one in favor of concluding that further research is necessary to see if extra fat calories ingested with an amino acid source will increase muscle protein synthesis. Lingering questions notwithstanding, post-workout milkfat was the factor that clinched the victory �?? at least in overnight-fasted subjects.

To put another nail in the coffin of the insulin spiking objective, post-exercise glycogen resynthesis is biphasic.25 Unlike the subsequent �??slow�?? phase which can last several hours, the initial �??rapid�?? phase of glycogenesis lasting 30-60 minutes immediately post-exercise is not dependent upon insulin. Maximizing post-workout hyperinsulinemia may be beneficial for athletes with more than a single exhaustive endurance-containing training bout separated by less than approximately 8 hours, but in all other cases, the benefit in �??spiking�?? insulin is nil.

In line with this theme, interesting research has surfaced in recent years challenging the idea that highly glycemic (and thus insulinemic) carbohydrates taken post-workout are the optimal for recovery. Erith�??s team found no difference between post-exercise high- and low-glycemic index (GI) carbohydrate intake on exercise performance the following day.26 In a similar study, Stevenson�??s team actually saw better next-day performance in subjects who consumed low-GI post-exercise carbohydrate than those who consumed high-GI post-exercise carbohydrate.27

Is spiking insulin necessary post-workout? Generally not.

-No greater inhibition of muscle protein breakdown has been seen beyond insulin elevation to approximately 15 μU/l, which is slightly above resting/basal levels of 5-10 μU/l.

-In one study, whole milk was superior for increasing net protein balance post-workout, despite the calorie-matched dose of fat free milk containing 81% more protein.

-The initial 30-60 minute �??rapid�?? phase of glycogenesis immediately post-exercise is not dependent upon insulin.

-There�??s no need to attempt to spike insulin for recovery purposes since maximal effects are seen at minimal elevations. Simply getting enough total substrate surrounding the training bout suffices, at least within the context of a 24-hour separation between exhaustive training of the same muscles. Multiple depleting endurance-type bouts per day (i.e., < 8 hours between bouts) may be the exception to this rule.

-On a related tangent, it�??s been commonly recommended to maximize post-exercise hyperglycemia and hyperinsulinemia by consuming high-GI carbohydrates. However, this strategy has been seen to offer no benefit on next-day performance, and one recent study even saw endurance impairment.

This is very interesting stuff. Relevant counterpoints, an antagonistic point of view supported by other studies, and more elaboration on " Multiple depleting endurance-type bouts per day (i.e., < 8 hours between bouts) may be the exception to this rule." seems warranted.

“lan Aragon has over 13 years of success in the fitness field. He earned his Bachelor and Master of Science in Nutrition with top honors. …”

I don’t know much else about the author but a quick google reveals he is involved in round-tables and such on other sports nutrition websites such as bodybuilding.com

this one is very good and debunks so much dogma it’s incredible, I need to find more hidden gold like this…

http://www.alanaragon.com/bodybuilding-nutrition-roundtable-alan-aragon-will-brink-jamie-hale-layne-norton.html

YES!

Awesome thread :wink:

Nice to see we’re having more and more free thinkers.

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Fascinating stuff. I sometimes wonder if we’re just going in faster and faster circles?

so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin

[quote]jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin[/quote]

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol.

year by year we seem to be getting closer to…

eat like your ancestors

some points from the roundtable:

(1) the macros in macros out model is largely correct, and eating carbohydrates close to bedtime has no averse effect despite widespread belief to the contrary

(2) high reps stimulate slow twitch muscle fibers, but so do low reps with heavy weights, as they have to be stimulated before use of the intermediate and fast twitch fibers. Bodybuilders should utilize all rep ranges and their are benefits to all types of rep work.

(3) fear of fruit and carbohydrates and over-reliance on supplements

(4) BCAAs are highly insulinogenic

(5) ALL FOUR authors viscously debunked the combining theory where carbs and fats are partioned. Aragon cites an actual study where it was shown that not only does partitioning make absolutely no difference in fat loss, it can actually result in averse effects including, ironically, unstable insulin levels.

"Furthermore, significant decreases in total body fat and waist-to-hip circumference ratio were seen in both groups, and the magnitude of the changes did not vary as a function of the diet composition. Fasting plasma glucose, insulin, total cholesterol and triacylglycerol concentrations decreased significantly and similarly in patients receiving both diets. Both systolic and diastolic blood pressure values decreased significantly in patients eating balanced diets. The results of this study show that both diets achieved similar weight loss. Total fat weight loss was higher in balanced diets, although differences did not reach statistical significance. Total lean body mass was identically spared in both groups. "

They mention respected nutritionists at the bottom and I think some might find the names relevant

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[quote]jdrannin1 wrote:
jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol. [/quote]

I think the pre- workout meal will only be superior to a post workout meal if he manages to keep it in while training.

One thing that should be kept in mind is that its pretty easy to spike insulin around a workout. there are many ways to do this.

another important point is that you need to distinguish between simply spiking insulin and creating an anabolic environment, which is the goal of workout-centered nutrition; the difference being the macronutrients and the ratio of these creating an insulin spike.

[quote]orion wrote:
jdrannin1 wrote:
jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol.

I think the pre- workout meal will only be superior to a post workout meal if he manages to keep it in while training.

[/quote]

Eat, then wait an hour before working out. Problem solved.

[quote]jdrannin1 wrote:
orion wrote:
jdrannin1 wrote:
jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? Spike it before or after, it still doesn’t change the need to spike insulin

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol.

I think the pre- workout meal will only be superior to a post workout meal if he manages to keep it in while training.

Eat, then wait an hour before working out. Problem solved.

[/quote]

Because puking is a smoother and better experience when the food is already pre-digested?

[quote]orion wrote:
jdrannin1 wrote:
orion wrote:
jdrannin1 wrote:
jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol.

I think the pre- workout meal will only be superior to a post workout meal if he manages to keep it in while training.

Eat, then wait an hour before working out. Problem solved.

Because puking is a smoother and better experience when the food is already pre-digested?

[/quote]

Haha
Very few people actually puke. We aren’t talking a massive meal of pasta and beef. Something simple and light goes a long way.

[quote]jdrannin1 wrote:
orion wrote:
jdrannin1 wrote:
orion wrote:
jdrannin1 wrote:
jehovasfitness wrote:
so, they just spiked insulin earlier with 35g of sugar, rather than later.

Am I missing something? spike it before or after, it still doesn’t change the need to spike insulin

He’s just pointing out that prewo consumption of nutrients can lead to a very high level of transport to muscle cells. Similiar and in a way, superior to pwo consumption. Follow what I mean?

He in fact, does not recommend this protocol.

I think the pre- workout meal will only be superior to a post workout meal if he manages to keep it in while training.

Eat, then wait an hour before working out. Problem solved.

Because puking is a smoother and better experience when the food is already pre-digested?

Haha
Very few people actually puke. We aren’t talking a massive meal of pasta and beef. Something simple and light goes a long way.[/quote]

exactly, while everyone is different to what they can tolerate, a meal that is comprised of carbs/protein 1 hr prior to training can be doable, though I prefer 1.5 hrs

Whew.

Interesting stuff.

However, regarding the P+C/P+F thing, hyperinsulemia and hyperlipidemia occurring at the same time is definitely probably something to avoid. Go to PubMed and search insulin, fatty acids, and lipotoxicity for more information.

The roundtable did not seem to address this issue. There seems to be quite a bit of evidence linking circulating fatty acids with decreased insulin sensitivity, which in itself would lend support for P+C/P+F.

Here’s an interesting one to kick things off.
[i]
Fatty acids and glucose in high concentration down-regulates ATP synthase beta-subunit protein expression in INS-1 cells.
Köhnke R, Mei J, Park M, York DA, Erlanson-Albertsson C.

Section for Diabetes, Metabolism and Endocrinology, Department of Experimental Medical Science, Lund University, BMC, B11, Lund, Sweden. rickard.kohnke@med.lu.se

Chronic hyperglycemia and hyperlipidemia exert deleterious effects on beta-cell function and impair glucose-induced insulin release, referred to as glucotoxicity and lipotoxticity. These abnormalities are associated with decreased glucose-induced ATP production; ATP serves as an important signal for insulin secretion.

To investigate the mechanism of the impaired ATP formation, we examined the effects of elevated glucose and fatty acids levels on ATP synthase beta-subunit expression, ATP content and insulin secretion in INS-1 insulinoma beta-cells. ATP synthase beta-subunit expression was measured by western blot, ATP content was monitored by ATP luminescence and insulin secretion detected by radio immunoassay.

Our result indicated that chronic exposure to high doses of fatty acids together with high levels glucose produced a marked decrease in ATP synthase beta-subunit protein expression. Reduction of ATP synthase beta-subunit protein expression occurred with a decreased intracellular ATP concentration and insulin secretion at high fatty acid concentrations.

These results indicate that high glucose together with fatty acids impair the production of ATP in beta-cells through the suppression of mitochondrial ATP synthesis. We conclude that ATP synthase beta-subunit may have an important role in the glucolipotoxicity of islet cells and suggest that ATP synthase beta-subunit might be a target of lipotoxicity in beta-cells.[/i]

Will be keeping an eye on this thread, I think some good discussion can come from this.

Not directly related, but interesting nonetheless.

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[quote]bushidobadboy wrote:

A nice counterpoint. I think the key word in the study you outline is “chronic”. In the roundtable discussion, I think they were focussing on more ‘normal’ dietary intakes, with a variety of foodstuffs, and not wildly elevated glucose and fat levels for chronic periods.

Bushy[/quote]

Bushy,

Absolutely right, you are. I meant only to show this one study as a sort of snapshot of a possible link between elevated free fatty acids in the blood and possible effects on insulin signaling and/or production.

There are lots of studies out there similar to this; and while the ones I have come across so far have not, to my knowledge, been done on healthy, weight trained individuals, there seems to be enough evidence to at least support the idea of meal combining.

Energy balance probably plays a large factor in this as well, and those who are eating in excess of maintenance calories through frequent meals could very well be coming close to replicating the “chronic” elevations in both insulin and free fatty acids which might approach the realm of deleterious affects on insulin production/effectiveness.

Most of the focus seems to be on the ability of the body to store fat when C+F are combined, but the effects on insulin sensitivity seem to be the more immediate issue, at least based on a large body of the research.

I’ll get to continue looking at this later on, its pretty cool stuff.