As an endurance athlete, aerobic threshold is the most important concept to understand. The definition in a sports science lab is where the level of lactate in the blood first starts to rise over resting levels of 2 mmol/l (millimole per liter). In practical endurance terms, it is the intensity of exercise where the body starts to produce more lactate than it can process. This is the tipping point between a pace that can be maintained all day and one that can only be maintained for a shorter amount of time. A well trained endurance athlete can usually maintain a pace above the threshold for 1-2 hours. The faster the pace, the shorter the amount of time the pace can be maintained.
Why Is the Aerobic Threshold Important?
The most important reason to know your aerobic threshold is that it is the upper limit of your all day pace. This is an intensity you can maintain for hour after hour and is even more critical on multi-day efforts. At this intensity, the body is able to provide enough oxygen to process the lactate that is being produced. The aerobic threshold is also the upper limit of energy production for movement where fat oxidation is the predominant energy source. At this intensity, the body is using a mixture of 50% fat and 50% carbohydrates to fuel movement.
Raising your Aerobic Threshold
Raising your aerobic threshold is the most important factor in improving performance in long endurance activities. Higher aerobic threshold means a greater aerobic capacity (the ability to perform low to moderate exercise for long periods of time). High volume training at or below the aerobic threshold will slowly raise the threshold over time. This allows an athlete to train at a higher intensity (faster pace, steeper grade, heavier pack) and sustain it for multiple hours. Even elite athletes spend at least 80% of their annual training time training below the aerobic threshold.
Using heart rate during ultra endurance training sessions to monitor intensity is not reliable for a number of reasons. There are a multitude of factors that can cause heart rate to increase or decrease without a change in exercise intensity.
Dehydration: Your blood volume (the amount of blood circulating through the body) decreases when you are dehydrated. The body compensates for this by increasing heart rate to get oxygen to working muscles.
Increase in body temperature: Training in hot environments or long endurance efforts that increase core temperatures increases heart rate about 10 beats per minute for every 1 degree rise in internal temperature.
Altitude: Decreases in barometric pressure at altitude reduces the amount of oxygen that is passed from the lungs to the blood. The decrease in oxygen causes the heart rate to increase to improve oxygenation to muscles during activity and at rest.
Caffeine: Many of the sports gels, blocks, waffles and drinks contain caffeine and can raise the heart rate within 15 minutes of consumption. It can take up to 6 hours for caffeine to leave your system.
Fatigue: Exercise induced fatigue can also lead to an increase in heart rate for the same level of intensity. This is primarily attributed to a decrease in muscular efficiency.
Emotional responses: Stress, anxiety, anger and excitement can cause an increase in heart rate. This can be as subtle as listening to a song or podcast that elicits an emotional response to a slip on a sketchy section of trail.
Equipment failure: While technology can be a wonderful tool, batteries die, blue tooth connections can experience interference and the contact between the device and the skin can slip during activity. The type of heart rate monitor can also vary greatly in reliability.
Heart rate can be a valuable training tool during shorter duration workouts to establish a feel for what intensity you should be training at, but as the workouts get longer in duration reliance on equipment should be replaced with how you feel and breathing to gauge intensity.
Creating an annual training plan is the first step in effective program design for the year and/or preparation for a single specific event. Periodization is breaks the year down into periods of around 4 weeks (mesocycles). Following a structured training program helps athletes prepare for the unpredictable nature of the mountain environment.
Step 1: Decide On Your “A” Events For The Year
The first step in creating an annual training plan is to decide on your “A” events. An athlete can usually only perform at their best or “peak” 2-3 times per year. In an Annual Training Plan (ATP) these are your “A” priority events that are a culmination of months of progressive training. A events require a full tapering phase of 2-3 weeks to absorb the months of intense training and insure you show up for your adventure rested and ready. I always encourage my athletes (and myself) to pick A events that scare them at least a little bit. This provides strong motivation to train and prepare for the trip. A events also usually require a few weeks of recovery afterwards
Step 2: Pick “B” Events to Serve As Benchmarks For Your “A” Events
“B” Priority Events are intermediate goals that serve as benchmarks in preparation for you primary goal. They serve as a test to see if your training is properly preparing you for your A Event. B Events usually involve a shorter taper (4-7 days). It can also serve as an assessment to identify any weaknesses that need to be addressed in upcoming training phases.
Step 3: Pick “C” Events that help to build towards your A and B events
“C” events are usually the weekly long endurance training sessions that don’t require a structured taper or need a long recovery period after. These workouts also serve as the framework for the short term training plan (12 weeks or less).
“A goal without a plan is just a wish” Antoine de Saint-Exupéry
Setting long term goals is a power tool that can help to motivate and focus your energy. The first step in goal setting is to sit down and take some time to think about your long term goals. This helps to create a long range plan with adventures to work towards in a logical progression. Long term goals are divided into three categories.
Dream Adventures Or Bucket List Trips
Set aside some time to relax and think about what your dream adventures or bucket list trips are. Where would you want to go if time and money were not limiting factors? Maybe you want to summit Kilimanjaro, trek the Inca Trail to Machu Picchu or climb the Lower and Upper Exum Ridge of the Grand Teton in a day. It is ok if some of these change over time as you add years to your adventure resume.
5 Year Goals
5 year goals help to develop a progression of trips increasing in length and difficulty. This progression builds fitness, experience and confidence. An example of 5 year goals with progressions for non-technical mountaineering would look like this:
First Year: One Day Climb Mount Hood
Second Year: Two Day Climb Mount Rainier Disappointment Cleaver Route
Third Year: Four Day Climb Mount Rainier Kautz Glacier Route
Fourth Year: Seven Day Mount Kilimanjaro Climb
Fifth Year: Twenty One Day Denali West Buttress Climb
1 Year Goals
1 year goals set the focus for the upcoming 12 months. An athlete can usually only perform at their best or “peak” 2-3 times per year. In an Annual Training Plan (ATP) these are your “A” priority events that are a culmination of months of progressive training. I always encourage my athletes (and myself) to pick A events that scare them at least a little bit. This provides strong motivation to train and prepare for the trip. Once you have decided on your A events, it is time to develop an Annual Training Plan or ATP.