I feel drained but there's still a while to go. Time to boost my spirits with a snack. I have
a choice either Peanut M&M's or an energy gel. Which should I go for? We are Pam and Gilbert, and in this
video, we discuss the merits of energy gel versus Peanut M&M's plus how to maximize the energy these
snacks can provide while bicycle touring. The gel packs 100 Calories of pure carbohydrate while
the small M&M bag has 250 Calories, equal parts carbohydrate and fat with a small bonus of protein.
Price and weight don't seem important when I'm really hungry, but the M&M pack is 30%
lighter per Calorie plus costs four times less per Calorie. Seems like a good deal.
Speaking of Calories, let's consider how many we need each day. A relatively inactive person
weighing 70 kilograms would require approximately 1800 Calories. 70% of this amount goes
towards supporting basic life functions like breathing, known as the Resting Metabolic Rate.
Non-Exercise Activities like walking to the kitchen, making a sandwich and watching
a YouTube video represent another 20% of the total. The remaining 10% is used to
digest and absorb food which works like a 10%tax on everything we eat called the Thermal Effect of Food.
As our sample person gets out of her chair and increases her level of activity from resting
to light moderate and finely vigorous, the number of Calories she requires increases accordingly and
can reach over 5000 for a triathlete in heavy training. The three basic sources of
Calories in our food are carbohydrate fat and to a lesser degree, protein. The liver processes
carbohydrates and converts them to glycogen, which is distributed to the muscles leaving behind a 20%
reserve in the liver to be used as required. The body can store about 2 400 Calories of glycogen,
sufficient for a day of moderate activity. This glycogen needs to be replenished every day.
Some of the fat consumed is used right away for energy while the rest is stored around
the body for later use. The body can store a considerable amount of fat, unlike glycogen.
70 kilogram person can easily have 10Kg of fat or more representing 90 000
Calories or 45 days of energy reserve. Finally, protein is used as basic building blocks to keep
cells healthy and create new ones. It can also generate energy, but only as a last resort.
Any daily excess of carbohydrate and protein will be transformed into fat and added to our storage.
The type of energy source selected by the body will depend on our fitness level and the effort
we expend. At rest, our body uses fat as the main source of energy, except for the brain
which uses glycogen. As we become more active, we use glycogen because it's easier to process.
At some point during moderate exercise, and equal
amount of energy is supplied by fat and glycogen.
This crossover point can represent a level of Maximum Fat burning. And as our activity level
increases further, most if not all of our energy will be supplied by glycogen, so its levels start
to deplete quickly. There's an exception: the extensive training of endurance athletes can
allow them to better tap into their fat reserve to reduce the rate of glycogen consumption, but that
doesn't apply to most of us. To get back to the most important decision of my afternoon, it's clear
that energy gel as pure carbohydrate is the ideal source of energy for strenuous activities while
the mix of nutrients in the Peanut M&M's better corresponds to more moderate activity levels.
When exercising for a period of time, the glycogen used first is taken from the muscles.
As our muscles are depleted, the liver provides its reserve to maintain our energy level.
If the liver runs out while we keep cycling, we'll experience "bonking" or "hit the wall".
It gets harder to keep riding, we feel drained and may even be light-headed. Obviously we should eat
way before we reach this point. The carbohydrates in an energy gel are easily absorbed thus
increasing blood sugar level quickly. This kind of food is described as having a high glycemic index.
But this effect
doesn't last long. Once the initial Sugar High passes,we may feel the need for additional gel
to reach the same energy level. Note that some energy gels include caffeine. With two packets
being the equivalent of a small cup of coffee. Although this is not energy per se, the stimulant
has a corresponding effect on rider morale. In comparison, the Peanut M&M's take more time
to digest and create a more gradual variation in blood sugar level. The protein content also
feels more filling to alleviate hunger pangs. As a bonus, the dopamine and serotonin in chocolate
are known as natural mood stabilizers, stimulating the brain Reward Center. It certainly works for me.
So, the energy gel provides 100 Calories that lasts less than one hour and the peanut M&Ms 250
Calories over a two hour period. How does this compare to the amount required while cycling?
We can evaluate this by multiplying the rider's weight by a factor called the Metabolic Equivalent
Task (MET). A 70 Kg cyclist riding at 15 km/h will burn 420 Calories per hour. That's
70 Kg times 6 Calories per Kg. So, a single portion of gel would provide about 25%
of the energy required for one hour. The M&M's, slower to absorb, but more calorie
rich would supply around 20% for two hours. So, how can we maximize these added Calories to reach our
destination? This graph illustrates the Calories required per kilometer as a function of speed.
At first glance, it appears that the slower we go, the more efficient we are. But no, that
doesn't take into account a Resting Metabolic Rate. When we add this to find the total caloric
consumption per kilometer, we see that the optimum speed to achieve the maximum riding
distance is between 10 and 15 km/h. Although this pace allows plenty of time
to enjoy the scenery, it can feel quite slow. Gilbert and I are not fast riders and, at the end of the
day, we've usually averaged 15 km/h, depending on the terrain profile.
This speed also permits us to maximize use of the more efficient direct drive 2nd hub gear.
On flat terrain, this translates to approximately 60 RPM cadence in 2+ or 4th gear.
To sum up, energy gel, quickly ingested and absorbed, is the ideal food for high intensity activities,
although more than one will likely be required on longer rides. The added caffeine can be a bonus.
The Peanut M&M's food content is more appropriate for moderate activities, like the kind of touring
we do. It's also a pleasure to eat, easy to share and has a magic effect on my mood.
To maximize our energy consumption on a longer ride we'll favor an average
15 km/h cruising speed with the efficiency of the direct drive 2nd hub gear.
How do you maintain your energy for cycling?Share what tasty way works for you in the comments below.