I recently got an email asking about aerobic versus anaerobic training. It read: “I am reading one of Tony Robbin’s books. He has a chapter physical health where he says aerobic is so much better for health than anaerobic. He also says that when you do aerobic you burn fat, whereas anaerobic burns sugar and glucose. Is that true? If so, why do I have aerobic endurance and more fat than my friend who doesn’t do much aerobic training?” - Amy
This is a great question, especially as it relates to a sport like soccer that requires such a blend of different fitness types. We need to be fast, agile, strong, and to sustain it at different intensities for the course of 90 minutes. There are also differences between positions, and I am not just talking about the goalkeeper. Midfielders need the most aerobic ability to go box to box and to constantly move in the midfield to track defenders and offer passing lane options. See:
First let’s define what aerobic capacity and training is versus anaerobic. Aerobic means "with oxygen," and anaerobic means "without oxygen."
Aerobic: Maximum oxygen consumption (Max. V02.) VO2, or maximum oxygen consumption, is a standard measure of aerobic capacity frequently utilized to evaluate the condition of athletes involved in endurance sports like distance running, cycling and rowing. Improvements in aerobic capacity reflect increases in blood volume, capillarization of all fiber types, and increases in the mitochondrial density and activities of oxidative enzymes. VO2 indicates a high capability to produce energy aerobically. A high VO2 is good for endurance sports, but it is also sport-specific, which is why a great cyclist isn’t always a great runner, and vice-versa. Some athletes like Eastern African distance runners are incredibly efficient at running with their long achilles tendons and light frames. Great cyclists produce more mechanical force against the pedal using their thigh muscles and rely less on spring-like tendons and rebounding off the ground with great efficiency. Greater aerobic capacity also means you can run at a certain threshold before your body enters anaerobic metabolism when you start feeling the muscles burn from the accumulation of lactate. As events range in track and field from the 400m and longer, a good aerobic engine becomes increasingly more important.
Anaerobic: Anaerobic exercise or training involves high intensity movements performed in a short period of time. Anaerobic glycolysis relies on glucose (and glycogen) as a fuel in the absence of oxygen. This occurs when energy at the cellular level, adenosine triphosphate, or ATP, is needed at rates that exceed those provided by the aerobic system that relies on the presence of oxygen.
There are 2 systems of anaerobic work:
Shorter term high energy phosphates, adenosine triphosphate and creatine phosphate – called "alactic anaerobic". This means the duration of effort is too short for lactate to accumulate. Think of a sprint under 10s.
Anaerobic glycolysis – called "lactic anaerobic" when the effort is sustained over 10s or so. Think of running a 400m.
Similar to my point about aerobic exercise, different anaerobic events favor different body types and structures.
What does all this mean for Amy’s question?
Aerobic training indeed burns a higher percentage of calories from fat since it is done at a lower intensity and doesn't require the fast energy provided by carbs (glucose). However, higher intensity training produces different adaptations to the body. Further, taking the intensity of exercise up also causes the body to burn more overall calories even after the exercise is over. This is known as Excess Post Oxygen Consumption. In contrast, the metabolism reaches homeostasis soon after the completion of lower intensity aerobic exercise. This does not mean 10 minutes of high intensity work burns more calories than an hour of walking. When it comes to fat loss, a calorie deficit must be created no matter what type of training you do. When it comes to improving performance the SAID principle is at play. Specific adaptations to imposed demands. I always like to point out the developed calves and quads of joggers at the expense of no glutes, hamstrings, hip flexors (hard to see). Jogging doesn’t place demands on those muscles whereas sprinting does. Another example is volleyball players- they have glutes and quads, but no hamstrings because they don’t ever sprint.
In terms of Amy’s question about health- there are some smart minds that suggests aerobic training at lower metabolic intensity provides the heart with some specific benefits by stretching the heart muscles. But anaerobic training including sprinting and interval training (jacking the heart rate up then giving it time to recover) has a ton of benefits including heart health - building muscle mass, overall bone density (jogging or just running doesn’t do much for bone density other than the lower limb), and also inducing lactate into the body has some nice benefits for the metabolism such as increasing growth hormone (good for more muscle and less fat profiles).
Regarding the comparison of Amy to her friend - when comparing two individuals, other than training which is a big aspect, one person may be better suited to aerobic sports with more slow-twitch Type I fibers while the other is more of a power/strength athletes with more fast-twitch Type II muscle fibers.
Endurance genetics and training versus power athlete genetics and training
What does this mean for us as soccer players?
I ran cross-country in high school my freshman to junior years. I got 3rd in League for my Varsity team that included a personal best of 16:47. I was aerobically fit, but was this good for soccer? In hindsight I will say confidently - no. Check out this quote from Charlie Francis, a one of the best track coaches of all time:
‘young athletes who do not achieve high levels of oxygen uptake during a treadmill test but who perform well over 10 to 40 meter sprints probably have inherited a high proportion of white power related muscle fiber.”
Cross-country consisting of a 5k or 3.1 miles is similar to the VO2 max treadmill test. As I ran well in cross-country, it showed my higher proportion of slow twitch muscles that with more long distance running only led to my speed and power decreasing. My ability to explode by defenders decreased. I also started getting injured a lot from either too much total running volume between soccer and cross-country, or unfavorable adaptations from sustained effort running. When I got to college I had the 2nd best beep test time but the worst vertical jump on the team. I also kept getting injured until I ramped up the weight-training. See this quote about the importance of powerful muscles for soccer to repeat sprints throughout a match: “the contractile properties of the muscles of the lower limb are related with the ability of these muscles to maintain or even increase performance in subsequent efforts and mitigate the injury risk especially in fatigued conditions (Rey et al., 2012; Malone et al., 2017; Simunic et al., 2017).” Running a slow pace is not the same as the diverse, dynamic, actions in a soccer game.
While I think soccer players, especially midfielders, need some aerobic capacity, taking it to the extreme and using long-distance running as the method are not optimal by any means. Although he is talking about sprinters and not soccer players, Charlie Francis goes on: “endurance work must be carefully limited to light - light/medium volumes to prevent the conversion of transitional or intermediate muscle fiber to red, endurance muscle fiber.’
Mike Boyle, a brilliant strength coach has written about this topic for hockey, but the same more or less applies to soccer in my opinion:
“One of the major drawbacks of conventional aerobic training is that the long slow distance methods most often used to develop aerobic capacity may compromise speed at the cellular level. In fact the adaptation of the muscular system to aerobic training is in direct opposition to the primary needs of the hockey player as indicated by the data in the chart. In effect, some players may be “training themselves out of the league” by adhering to the aerobically oriented off-season programs of many NHL teams. A larger, highly skilled player may not be as adversely affected as a marginal one in the NHL. Marginal players generally have lower vertical jumps and anaerobic power scores (based on the Wingate 30 second sprint test) than their more highly skilled counterparts. This indicates that these players are already at a disadvantage that will only be magnified by an aerobically oriented training program. In a simplified view, muscles are made up of three types of fibers; fast twitch (anaerobic), slow twitch (aerobic) and intermediate. The ratio of fast twitch fibers to slow is one of the primary determinants of success.”
Soccer involves more sustained aerobic activity than the short shifts of hockey, but it is still an explosive sport with aerobic system needed for recovery between explosive bouts. If you look at the English Premier League as an example, every player is fast and powerful. Speed and power are what make players like Mo Salah special. While beep tests and aerobic tests are a good part of a player’s profile (midfielders will usually have the best aerobic capacities), a better predictor of success and something to aim for is a higher vertical jump or a faster 30m time. Relative strength, or how strong you are in an exercise like the Rear Foot Elevated Split Squat compared to your body weight are good predictors of vertical jump and short sprint speed in youth soccer players. How do you compare to these U-21 players?
The aim of the study was to analyse and compare the actual level of sprint ability in 10m, 30m and 50m from the point of view of playing positions of Slovak national under-21 football players U21 (N = 20, goalkeepers = 2, defenders = 4, midfielders = 8, forwards = 6) in time of qualification for European Under-21 Football Championship 2011.
There is also the focus on repeated sprint ability. One popular test is the RSAt that includes seven repetitive sprints of 30 min, with 20 s of active recovery between sprints. The mean is the average of all 7 sprint times across each age group. Peak sprints are not shown below, but for yourself - a high peak but a big change means you are fast-twitch machine but have a hard time sustained it and are possibly unfit. A low peak but high maintenance means you are slow-twitch but fit. How does your average (mean) and percentage of change from sprint 1 to sprint 7 compare to these players:
Nowadays since everyone has access to a treadmill, so here is a cool test from Mike Boyle that blends power and endurance. I wouldn’t say this correlates too much with what we encounter in soccer, but it is a fun test and you can’t do well if you are slow or unfit. This one really hits the anaerobic glycolytic fitness. It is the 10/10 Test. To perform the test, begin running at 10 MPH and 10 % incline and run to exhaustion. When you can not longer go on, simply place your hands on the rails and spread your feet off the treadmill onto the sides. Over 1:00 is good, over 1:30 is great, over 1:45 is excellent. Apparently 3 minutes has been achieved by a soccer player Mike Boyle trains, but that is extremely rare.
To summarize:
-Our body uses a blend of different energy systems depending on the demand
-Genetics and physical structure will determine part of how good we are at different activities and sustaining them
-Soccer definitely requires some aerobic capacity, but just enough to recover between explosive bouts for forwards and defenders. Midfielders need more to go box to box
-Train for strength, speed, and power, and raise the ceiling of what great things you achieve on the pitch
If you want to learn more about how to get stronger, faster, and prevent injury, check out my affordable book Soccer Dominance on the Books and Virtual Coaching page.