By Owen Beck

“Is this normal?” asked Agnes Scott College’s newest head Cross Country Coach, Molly Carl, referring to a 90-degree fall day last year, “Shouldn’t it have cooled off a bit by now?” Welcome to Hotlanta!

While this Northerner may still be acclimating to Georgia’s sweltering heat, Coach Carl is very familiar with successful cross country running. Prior to arriving to Agnes Scott College, Coach Carl was a standout cross country and track athlete at Southern Maine University. Following undergrad, she was an Assistant Cross Country Coach while obtaining her Master’s degree in Exercise and Sport Studies at Smith College. Coupling her experiences and enthusiasm for the sport, Coach Carl is ready to lead the Agnes Scott Scotties to cross country prominence.

Collegiate cross country running is usually between 2 to 3.7 miles on non-paved paths and is an intensively aerobic exercise. In other words, it is exercise that improves and requires the body to absorb oxygen efficiently. Well acquainted with how to get runners prepared to compete, Coach Carl came to Agnes Scott with “a vision and a plan for the program and it got people excited to join forces with her” according to Agnes Scott College’s Cross Country Graduate Assistant Coach, River Bonds.

Coach Carl trains Agnes Scott athletes with the same science-based training program that led her to All-American status as a collegiate athlete. Like an astute writer, she uses an outline to guide the training schedule. “I see where our championship races are, then work backwards,” explains Coach Carl. This approach of reverse chronological planning is standard for coaches from all sports to properly peak their athletes for late-season competitions – Agnes Scott’s championship cross country races are usually in November. Next, Coach Carl lays out four, six-week training phases to prepare her athletes for November’s races. In each training phase, specific workouts are featured to enhance certain body processes that improve distance-running performance.

Naturally, the initial training phase is the easiest, as its primary goal is to re-acclimate the athletes to running consistently. Coach Carl may advise athletes who did not run competitively during the spring to build up to running 15 to 30 miles per week over this phase. Not only does this phase prepare athletes for more rigorous training, but it elicits adaptation that improve distance-running performance. For example, to keep running, leg muscles need a constant supply of oxygen-rich blood, like a car engine needs gas. Consistent running increases the stroke volume, the volume of blood pumped from the heart with each beat, which improves the body’s ability to circulate oxygenated blood to leg muscles and keep running.

Once the initial adaptations are in motion, Coach Carl’s athletes transition to the second training phase, where “repetition” workouts are introduced to their weekly schedule. Repetition workouts entail running relatively short and fast intervals with long recoveries between repetitions. For cross country athletes, repetitions workouts are generally 200 to 400 m (a half to full length of an outdoor track) at current mile race pace with 1 to 8-minutes rest. The primary goal of these workouts is to improve athlete’s running form, since optimizing form maximizes performance. Improved running form may decrease the rate of energy that an athlete expends while running a given speed. This is analogous to how much gas a car burns while driving at a constant speed (less gas is better). While considering other factors, athletes who consume less energy to run at a given speed can outperform their competitors by having the ability to run farther at a given speed and faster at given aerobic intensity.

“…Then I get them for the next two phases… when they are back on campus” continues Coach Carl. You read that correctly, 12 of the collegiate 24-week training program is completed prior to the first day of practice. “You have to be intrinsically motivated to do well”, she adds. Indeed.

Athletes are welcomed back to school by the most difficult training phase. By now, each week athletes run multiple easy days, two structured workouts (e.g. repetition workouts), and a long run. Long runs are ~25% of the respective athlete’s weekly mileage (e.g. ~10 mile long run for an athlete running 40 miles a week) and serve to improve the number of blood vessels that transport oxygen to exercising muscles. Notably, the primary goal of the third training phase is to increase the maximum rate of oxygen that an athlete can uptake, transport, and utilize to generate energy. Much like how football players love 40-yard dash times, this is the measure that endurance athletes obsess over due to its close relationship with distance-running performance. To increase her athletes’ maximum rate of oxygen uptake, Coach Carl has the team perform classic “interval” workouts that consist of 3-5 minutes of intense running with 2-3 minutes rest between intervals.

Another intense, albeit a more enjoyable, aspect of phase three are the beginning of cross country races. Cross country races are generally 2.0 to 3.7 miles and start around the end of August or beginning of September. Ideally, Coach Carl’s team runs 5 to 6 races before the November’s championships.

The final training phase is intended to simultaneously improve another physiological process and freshen the athletes up for the key races. Physiologically, to sustain a relatively fast running speed, athletes expend energy without the presence of oxygen at the muscle-level. If athletes expend too much of this energy source, their blood will likely become more acidic than normal, resulting in the sudden feeling of having heavy legs. To train the body to buffer this race-slowing feeling, athlete’s run workouts include a moderately hard continuous run (e.g. 20 minutes) or multiple repeats with short rest (e.g. 5-minute intervals with 1-minute rest). These workouts are perfect for the final training-phase because they are also relatively easy to recover from due to their controlled intensity. In the last few weeks of the season, athletes decrease their overall weekly mileage to enter the championship races rested and ready.

XC Season is finally here!!! Let’s wish our team good luck as they head to their first meet of the season #LeaveALegacy … here’s some footage from the Stone Mountain pre-season run #GoScotties pic.twitter.com/KHQ7xl0s4G

— Agnes Scott Cross Country (@ASCCrossCountry) August 31, 2018

Even though this science-based training approach develops key physiological parameters that influence distance-running performance, Coach Carl carefully customizes the training of her athletes as the season progresses on an athlete-by-athlete basis. “You cannot just plug a human into a system and be like this should totally work out” she says with amusement. Subtleties like altering training to handle life events, mimicking training environments to resemble race courses (e.g. incorporating hills to prepare for hilly courses), and developing race plans that cater to each athlete’s strength are just a few ways that Coach Carl artfully brings science-based training to life.

Whether you are preparing to get back into shape, run in the world’s largest 10-kilometer race (Atlanta Track Club’s Peachtree Road Race), or guide athletes through their cross-country season, these science-based training methods can be helpful. After all, what do you have to lose? Except for a few minutes on your next race.

By Kellie Vinal

You might not expect it, but nestled just southeast of the city limits of Atlanta lies a 40-acre oasis of grazing pastures and scrubby brush that 40 adorable adult dairy goats call home. Those in the know will tell you it’s where to find the best goat cheese in town — Decimal Place Farm. A mere 11-minute drive from the Starlight Drive-In Theatre, Decimal Place thrives as a source of freshly made cheeses, delivering feta, mozzarella, creamy chevre, and cheddar to grocery stores, farmers markets, and well-known restaurants around Atlanta.

Mary Rigdon has been running the farm since her family took over the land in 1995, and is a tried-and-true expert of her craft. With a degree in animal science and background in research with pigs, sheep, and cattle, she’s incredibly knowledgeable when it comes to animals. And it shows – she’s raised her herd of Saanen dairy goats since they were little, and they are noticeably trusting and calm in her presence.

“We’re truly all about keeping the animals happy and healthy,” she says. “I love the animals. The better I treat them, and the better I understand them, the better they give back to me.”

Her almost otherworldly intuition puts her goats at ease, and they find comfort in the routine she’s established for them. “Goats are all about routine,” she says. “So, twice a day, at the same time every day – we milk.”

Mary fell in love with Saanen goats – a breed originating from the Saan valley in Switzerland — for their sweet temperaments and superior milking qualities. Over the years, she’s carefully bred and selected her goats for their impressive milk production, as well as their physical characteristics.

“Each animal is identified as to who their mother is and their father is, and I’ve got milk records on the mothers for the last 20 years,” she explains. “I’ve selected all through those years for straight legs, a level top-line, and good feet — so that they can travel through my pastures and do a good job of grazing, which is what they’re meant to do.”

Most days, you can find the goats happily roaming and grazing around the 40 acres of farmland, rotation of which Mary strategically orchestrates to keep both the land and goats healthy.

“They graze the woods that are around us,” she says. “We have poison ivy, privet, honeysuckle, and the goats eat that, along with the tree leaves and the acorns that are around, and they turn it into that tasty milk.”

When baby goats are born, the mother starts giving milk – called lactation – and generally, each goat gives milk for approximately 300 days. The goats at Decimal Place Farm usually give about a gallon a day, if not two, for those 300 days, and Mary and her crew turn it into cheese.

Mary isn’t shy about diving into the science behind it all, either — from the selective breeding to optimization of milk production, to the science behind different kinds of cheeses. Her enthusiasm is palpable as she explains lactation, sketching a curve on the notepad in the milking room.

With a twinkle in her eye, she says, “I eat this [science] stuff up. I love it!”

She explains that, after extensive calculations and cross-referencing of milk records, she’s selected for goats that maintain a long, level lactation curve, rather than a large, brief spike in milk production.

It All Begins With Milk

The process of making cheese starts in the milking room. Mary’s milking room facility accommodates up to ten goats at a time, each of which gets personal attention to ensure they’re in tip-top shape before beginning. Not only are the goats tested in advance for tuberculosis, brucellosis, and other diseases, but their milk undergoes a quick, simple test that confirms each goat is in good health and thus producing healthy milk each day.

Once the goats’ udders are dipped with a bleach solution and wiped clean, and their milk is deemed infection-free, the milking process begins – either by hand or by a vacuum-driven machine that mimics the action of a squeezing hand, gently pumping the milk to a receiver. When the receiver fills up with milk, the milk completes an electrical circuit, activating a pump that transfers the milk up and through the wall to a bulk tank.

The milk stays chilled in the bulk tank until Mary’s ready to make the cheese, which is typically the same day the goats are milked. Each day is different, with local chefs and restaurants requesting a variety of cheeses in different quantities. Mary makes sure she’s ready for anything.

“If one chef for one restaurant wants a cheddar and a chevre, and another restaurant wants a feta, then I can make to the orders that I have that day,” Mary explains, “and that way it keeps the cheese fresh for everyone.”

Each batch of milk is first pasteurized – heated above 146 degrees Fahrenheit for 30 minutes – in order to kill any harmful bacteria, then cooled back down. From there, small batches of milk are processed at a time, undergoing slightly different processes to achieve the desired consistency and taste.

The Transformation From Milk to Cheese

In each case, the basic concept is this: milk exists as an emulsion, meaning that microscopic clumps of milkfat proteins are suspended in a mostly watery environment. At the heart of cheese-making is simply removing the water from milk, concentrating the proteins and fats that are already there into solid curds.

To begin the process, Mary adds a starter culture of mesophilic (or medium heat-loving) bacteria, which helps “ripen” the milk, converting milk sugar to lactic acid. This helpful bacteria culture helps the good bacteria in the milk flourish and ultimately makes the chemical conditions just right to develop the desired flavor and texture of the cheese.

Mary explains that milk contains two types of proteins: casein and whey. Casein proteins have little tails that form a protective surface, preventing the molecules from clumping together. During the process of cheese-making, Mary adds an enzyme called rennet, which slices those little tails off the casein proteins. As a result, the casein proteins begin to lump together – called clotting or coagulation, which sets off a domino-like effect until nearly all of the molecules have clumped together. The milk is converted to a solid – called a curd – and the remaining liquid portion (called whey) is separated.

You can make any kind of cheese with the goat milk, Mary explains: but it’s the temperature, the time, and the amount of good bacteria and rennet you add to the milk that makes the difference. For instance, to make Decimal Place Farm’s signature creamy chevre, Mary adds her culture of good bacteria to a pot of milk with just 5 drops of rennet – a little bit goes a long way with that stuff. Compared to other cheeses, creamy chevre requires more culture, less rennet, a lower temperature, and a much longer incubation time.

She explains that she makes feta cheese using a larger amount of rennet, a much shorter incubation time, and a higher temperature, so the bacteria grow more quickly. Over the years, she’s developed a precise protocol for each type of cheese, giving each type a signature flavor that keeps folks coming back for more.

“Now there’s the art, and there’s the science,” she says with a smile.

Once separated into curds, each type of cheese undergoes a slightly different process to achieve the proper amount of moisture. Most undergo a combination of pressing, scooping, straining, slicing, and salting, the protocol varying a bit for each. Creamy chevre has the highest moisture content of all the cheeses, while cheddar – which requires a few extra steps – has a much lower moisture content, and can keep much longer as a result.

“Making cheddar is a long, involved process,” Mary explains, as she twists the handle of a cheddar press, mechanically pressing the cheese to remove excess moisture.

Cheddar cheese undergoes several rounds of moisture removal before it’s sealed in wax, then aged.

Cheese, Love, and Science

When she’s not tending to goats or making tasty cheeses, Mary shares her love of science through her passion for teaching. She regularly leads tours and classes on the farm to curious folks of all ages, guiding groups through pastures and leading cheese-making demonstrations.

Her enthusiasm is infectious as she describes why some cheeses are yellow, while others are white: cows transfer carotenoids (a natural pigment found in grass) from their diet to the milk, where they bind to the fat and end up in the curds. Goats, however, (along with sheep) do not pass carotenoids to their milk, so their milk is white.

Her extensive knowledge comes in handy, especially when she encounters folks with allergies or intolerances to cow’s milk.

“The reason is,” she explains, “goat milk [has] shorter chain fatty acids. A cow milk fat molecule would be the whole alphabet, while a goat milk molecule would be ABCD — a shorter chain.” She continues, “The reason why so many people have tolerated goat milk rather than cow milk, [is that] their stomach acids don’t have to work so hard to break the bonds.”

Whether you’re allergic to cow’s milk or not, the cheese at Decimal Place Farm is absolutely worth a try. If you’d like to check out some of Mary’s cheese for yourself, you can find her at the Freedom Farmers Market at the Carter Center each Saturday. You can also find her cheeses at the East Atlanta Village Farmers Market on Thursdays, and at Rainbow Natural Foods in Decatur. For more information about Decimal Place Farm and where to find their cheeses, you can find them on Facebook, Instagram, or visit Decimal Place Farm’s website.

How do circus performers balance a ladder on their chin? How does inertia affect aerial shows? The science behind the circus is both intriguing and entertaining, so we’ve turned to Imperial Opa member John Indergaard to help us learn a bit more.​

Imperial Opa member John Indergaard shows off his juggling skills in their practice facility!

John, a self-described “general goofy person,” began juggling at seven-years-old in P.E. class and turned the skill into one of his favorite hobbies after his mom bought him juggling clubs for his birthday.
John’s introduction to the circus actually happened thanks to the Atlanta Science Festival. John was studying physics with a research focus on molecular beams at Georgia Tech. While hanging out in the demo room of the Howey Physics building one day, John and a friend gave a tour to a professor who wanted to create a “science of the circus” event for the upcoming Atlanta Science Festival. Naturally, John’s ears perked at the chance to incorporate his favorite hobby and his passion for math and science. Since then, John joined the circus and has become the science expert at Imperial Opa, leading our annual Science of the Circus event each year at the Festival. We hung out one night at circus practice with John to learn more about how he intertwines his two passions at one of Atlanta’s best circus acts in town.

What areas of science are involved in circus performance?

Every circus act can be viewed through the eyes of a scientist. Scientific thought can be used to analyze anything in nature, so I would say that I dissect circus feats through scientific scrutiny more than develop acts based off of scientific principles.

Partner acrobats take hours of practice and teamwork! The scientific trick to these poses comes in analyzing the center of mass, since there can be several acrobats at a time leaning away from each other.

Tell us more about how you use science to perfect your craft.

The great thing about using the circus as an avenue of science outreach is the ubiquity of circus arts in the world and the large degree of separation between circus and science. When people think of circus they probably don’t think of science at all, and vice versa. When an audience, particularly younger students, are presented with an amazing circus act that is given a detailed scientific description it brings up a conflict in their minds: How is this person making the circus about science? What does science have to do with anything here? I try to use these moments to help people realize that science was not created for the classroom or made to be a boring homework assignment, but rather science has been cultivated for thousands of years to give us the most useful and detailed methods to learn something from the world around us – whether that be atomic physics, chemical reactions, or an acrobat on the trapeze! Science can be everywhere around us!

This act uses balancing, juggling, and partner acrobats to wow their audience!

What are the main acts of your circus? Could you walk us through the science of each of them?

Sure thing! I’ve broken down the science behind aerial, partner acrobats, tumbling, balancing/juggling, and our fire show below.

Aerial

Aerial

Aerial acts can be performed on silks, lyra, rope, trapeze, and other apparatus. When we scientifically analyze these acts we focus on the rotational motion of the aerialist. Specifically, we like to discuss spinning and how the positioning of our arms affects our rotation. Arm position changes your body’s tendency to resist acceleration as it rotates around an axis – extended arms slow the rotation, while tucked arms speed you up. This helps maintain a law of nature – conservation of angular momentum – which depends on rotation speed and shape of the rotating object. If shape changes, then the speed must compensate to conserve angular momentum by changing as well. Aerialists use this principle of physics to seamlessly transition from rapid rotations to slow elegant motions.

Partner Acrobats

Partner Acrobats

Partner acrobatics often demonstrate amazing feats of strength and flexibility, stacking and tangling many people together. We like to demonstrate positions that look odd due to acrobats leaning or hanging from one another. The scientific trick to these poses comes in analyzing the center of mass, since there can be several acrobats leaning away from each other whom look like they should be falling over. However, the center of mass always remains above the stable point (like feet on the ground) even though there is no physical mass at that position! In these cases, a basic understanding of physics can change the way that acts are viewed.

Tumbling

Tumbling

Watching our tumblers jump and flip over each other and audience members always puts a smile on people’s faces! The physical concept demonstrated here is the conversion of linear momentum into angular momentum, like when an acrobat is running in a straight line and all of a sudden tucks into a rapidly rotating position as they make a flip. Since momentum is always conserved, acrobats take their linear momentum (running in an extended body position) and rapidly convert it into angular momentum (flipping with arms and legs tucked). That is why you see these acrobats running so quickly before performing their feats – with all that momentum built up all they have to do is change their body position ever-so-carefully to generate the rotation necessary to perform their amazing flips and twists.

Balancing/Juggling

Balancing and Juggling

The language of juggling is truly the language of mathematics. All juggling tricks can be described using numbers that represent the number of beats the objects spend in the air, and where the object begins and ends its pattern. Ignoring gritty details, generally speaking odd numbers describe throws that are thrown and caught by different hands while even numbers describe throws to the same hand, with larger numbers of objects requiring higher throws (see siteswap.org for more on this). Perhaps not surprisingly, if you ask a juggler, it is very common for them to have some background or interest in science and mathematics.
Balancing is fascinating from a physical point of view. This boils down to the center of mass and moment of inertia (that is, the tendency to resist rotation) of various objects that a circus performer may want to balance on their chin, or nose, or forehead. An object with its center of mass higher up will have a larger moment of inertia and therefore will require more time to fall. These objects fall more slowly and thus are easier to balance. For instance, it is always amazing to see a performer balance something large like a ladder on their chin, but since the center of mass of the ladder is so high it is actually relatively simple to balance compared to something less impressive like a fork or spoon!

Fire Shows

Fire Show

A scientific view of fires requires chemistry! Choosing a fuel with a low burning temperature to allow the performer the most comfort and a high burning efficiency to reduce smoke is essential for a successful fire performance. There can even be fuel chemical additives to allow fantastic colors in the flames! A performer must also understand the idea of ignition temperature, since a wick doesn’t need to be flaming to reignite when reintroduced to the fuel.

What is your favorite part of the circus? Can you share any science secrets about conducting it?

My favorite part of being in the circus is getting such undivided attention from kids who are amazed at all of the diverse acts! Using this amazement to bring young people into a scientific discussion is a slick little trick I like to use to insert science into their everyday lives, especially when they least expect it.

Stay tuned for more information on Imperial Opa’s upcoming #ATLSciFest event in March 2018!