In recent years, the endurance community has done a major push to promote chocolate milk as a great post-training recovery drink. It’s especially prominent in the triathlon world. Today’s article discusses why this is a myth, and backs it up with science.
First, let’s understand the nutritional profile of 1 liter of chocolate milk, which contains approx. 100 grams of sugar. When one ingests sugar, the body stores that sugar in the liver and muscles (glycogen). However, the body has a very limited storage capacity so anything over that capacity goes directly to body fat. So, if you are in the majority of people, and would like to lose some body fat, and you want to take in this much sugar without putting on fat, then you will need to have emptied / depleted your glycogen stores in order for the extra sugar absorbed to be used to renew your glycogen stores. Otherwise, it goes to fat.
Studies conducted on chocolate milk have attempted to determine the optimal amount to best promote post-training recovery and athletic performance. According to StrengthSensai.com, most of these studies followed a particular protocol:
- Study participants were subjected to intense exercise at 70 to 85% of their VO2 max (aerobic max) during 1 to 3 hours. The purpose of this step was to considerably reduce glycogen stores since 70 to 80% of the energy spent at 85% VO2 max is derived from glycogen.
- Recovery periods between 4-8 hours were followed to allow the participants to replenish their glycogen stores with chocolate milk.
- Participants were then subjected to a second high intensity exercise (VO2 max between 70 and 85%) until exhaustion. The difference in time or distance between the performances is meant to determine which sports nutrition supplements helped the athlete the most to recuperate between the two sessions.
This protocol mimics the situation for certain Olympic athletes and/or elite cyclist (think Tour de France), but what about the average age-group athlete training for a half marathon, 5K, sprint tri, or cross-fit competition? Does chocolate milk make sense?
- Glycogen stores fall between 25% – 40 % after an intense strength training session, which is not really that much. These glycogen stores are best rebuilt through normal nutrition, WITHOUT ANY SUPPLEMENTS, within 24 hours of the training. The latest literature suggests that in order to maximize MPS (muscle protein synthesis); what you really need is to make sure to ingest the total amount of grams of protein needed within 24 hours.The old “magic 1-2 hour window” has little scientific evidence to support it.That doesn’t mean that protein powders are bad.If you have trouble getting your total protein in over the course of the day, then they are very useful, so long as you get a quality brand.
- Further, multiple recent studies show that 20 – 25g of protein is the recommended amount to take after a strength training.One liter of chocolate milk contains approximately 30g of protein, but it’s mostly casein (80%) rather than whey, and casein is sub-optimal post-recovery.Casein is great for other purposes, just not after your workout.
- Chocolate milk also contains a high amount of fat (unless it’s skim), which is also sub-optimal post-workout.The fat in milk/dairy is good for you but not what you want for tissue repair and recovery.
- Scientific studies also show that optimal carb: protein ratios vary between 1:1 and 3:1.So, if you assume that you need 20 grams of protein, then the upper level of carbs should be 60 grams (which can come from natural sources and/or added sugar).Remember at the top of the article where I mentioned that 1 liter of chocolate milk contains 100 grams of sugar.See the problem – way too much unnecessary sugar!!
- Let’s take it 1 step further – it is widely known that the type of sugar used in most chocolate milk products is high fructose corn syrup, which when consumed in excess has been implicated in many disease states, such as increased cholesterol, LDL particles and visceral obesity.
- After intense cardiovascular training (think marathon), glycogen stores in the liver are low, so the sugar in chocolate milk can help to rebuild glycogen levels…..sort of.Let’s dig in to the science.Lab experiments have shown that glycogen stores decline by 50% – 75% after 3 hours of high intensity cycling.Similarly, for marathoners, there is a similar glycogen decline between miles 22-24 of intense running.In these cases, chocolate milk may be a suitable recovery drink.
- But that is not most people.If you don’t cycle/run/swim at that level of intensity for that amount of time, then you probably don’t qualify for chocolate milk as a smart recovery choice!Why?The extent of the glycogen loss is strongly correlated to the effort expended.
- So, for the average person pursuing regular endurance training, the best way to rebuild glycogen stores is through normal nutrition, WITHOUT ANY SUPPLEMENTS, within 24 hours of the training.
When the various endurance communities decided to promote chocolate milk as the “BEST” recovery drink, they chose elite level athletes to be their spokespersons. That’s Marketing 101, and makes sense from a business perspective. However, when you look at this scientifically, you need to be honest with yourself and ask the all-important question: Am I an elite athlete and do I train like an elite athlete?
If the answer is no, as it is for most of us, then chocolate milk is not the right choice. As noted above, regardless of whether your focus is on strength training or endurance, you want to opt for a recovery mix of 1:1 to 3:1 carbs to proteins, and make sure to ingest the proper total amount of protein within 24 hours. Not getting enough protein will significantly hamper your ability to repair and recover. Strive for approximately 1 gram of protein per pound of body weight, i.e., if you weigh 135 pounds, make sure you eat 135 grams of protein daily.
If you enjoy chocolate milk, go ahead and have a glass once in a while, and consider it a treat (i.e. a dessert). Don’t be swayed by commercials and/or magazine ads saying that it’s what you NEED…..because it’s NOT!!