Changing cadences to alter efficiency and adapt to race strategies
By Sarah Willis, PhD
We all know that cross-country skiing is a complex sport where competitions occur over a wide range of distances and disciplines. In World Championships, athletes compete in individual events of 10/15 km time-trial, 15/30 km mass start pursuit, 30/50 km mass start, 1.3-1.8 km sprint races including a qualifying time-trial followed by 3 subsequent knock-out heats, as well as team events of the 5/10 km team relay and 3 x 1.3-1.8 km team sprint. These races have an average duration ranging from about 3 minutes to more than 2 hours for 50 km. In addition, long-distance mass start races of 40-90 km are also part of regular season athletes.
In addition to a range of competitions, there are a variety of sub-techniques within 2 main disciplines of classical and skating/freestyle. Classic skiing includes sub-techniques of diagonal stride, double pole with kick, double poling, and herringbone, while skating has sub-techniques of (G2/V1, G3/V2, G4/V2 alternate, G5/no pole), along with downhill tuck and turn techniques used in both styles (Sandbakk and Holmberg, 2017; Andersson et al., 2010). While skiing, we transition between these sub-techniques depending on several internal (perceived effort, strength, physical capacities, pacing strategy, etc.) and external factors (track profile, snow conditions, ski speed, etc.). During races, skiers travel at speeds from 5-70 km/h and throughout terrain profiles including -20% and +20% incline with varying snow conditions at altitudes ranging from 0-1800 m above sea level. In fact, athletes may transition between these sub-techniques 30 times in a sprint race and up to several hundred transitions during longer distance races (Andersson et al., 2010; Sandbakk et al., 2014a, Sandbakk et al., 2014b). Therefore, there are a large range of motor skills required to learn and master cross-country skiing.
The overall time is spent on uphill, flat, and downhill terrain where the best athletes are faster on all types of terrain (Sandbakk et al., 2016), while the highest work rates are found on uphill terrain and intensity is reduced during downhill sections (Bolger et al., 2015). About 50% of the race time is spent on uphill sections therefore training of these techniques and fitness are crucial (Sandbakk and Holmberg, 2017).
Changes in the cycle and technique biomechanics
In cross-country skiing, there are lower speeds and less drag than with road cycling (for example). Due to undulating terrain, there are quick changes in incline and work rates across the various terrains encountered, which makes it difficult to change the racing position (passing/making moves/following). The majority of competition involves mass start races with head-to-head competition where tactics are paramount and races are often decided in the final sprint.
Therefore, it is important to understand the situations as well as the reasoning to make transition between sub-techniques and change speed with cycle length and/or cycle rate. Speed can be increased by elevating cadence, increasing power (longer cycle lengths), and/or changing to a faster sub-technique (Marsland et al., 2018).
These reasons for adjusting speed/sub-technique may be linked to a number of factors which include but are not limited to:
- Biomechanics/kinematics of movement within the technique for improved mechanical efficiency (purely body movement pattern) and energy utilization (metabolic workload and anaerobic/aerobic capacity)
- Faster (stronger) skiers are characterized with longer cycle lengths and lower cycle rates which help to explain the demonstrated high work economy and skiing efficiency (Sandbakk et al., 2010; Sandbakk and Holmberg, 2017a). It takes a lot of strength to attack each section of the course with long cycle lengths and lower cycle rates/cadence. That being said, when feeling tired it is wise to adapt your movement pattern to shorter cycle lengths with higher frequency to avoid or reduce speed (i.e., to adjust for various levels of strength in the upper and lower body). With training, you can manage a more economical use of technique (i.e., with less power required taking shorter steps at higher rate) to maintain speed without exerting more energy.
- The use of rapid cycles and trying to maintain longer cycle lengths are characteristic when accelerating on steep hills, and at the start and finish of the race (Sandbakk and Holmberg, 2017a).
- Sprint racing is characteristically different than distance racing, where sprint races require to attain higher cycle rates across all sub-techniques (Marsland et al., 2018).
- Upper body strength (applicable in double poling as well as many technique gears in both styles of classic and skate skiing)
- At some moment in double poling, the cycle length reaches a maximum and then you need to increase the cycle rate to reach your maximal speeds (Lindinger 2009, Nilsson, 2004).
- Leg strength (applicable primarily in skate skiing with crossover to physical capacity overall)
- Perception and occurrence of fatigue resulting in both short duration events resulting in loss of strength and reduced performance (Zory et al. 2006, 2011; Zoppirolli et al., 2016) and ski marathons (peripheral – local fatigue in quads from skate skiing (Millet and Lepers 2004), triceps from double poling (Nicol et al., 2006)
- To avoid/reduce fatigue in ski marathons with primary use of double poling, researchers have suggested to assess the elbow and ankle movements and accentuate an effective forward lean during the propulsive phase along with an increase in cadence, as force generation and cycle rate decrease with extended race times and accumulated fatigue (Zoppirolli et al., 2018)
- Increased limitation of your range of speeds (gears) available as fatigue sets in (suggested by Marsland et al., 2021)
- Make an attack to accelerate pace/cadence to establish position or break away using your strengths and abilities / actively respond to tactics initiated by competitors (support in recent article Marsland et al., 2021)
- Terrain topography (i.e. terrain demands use of certain technique; use terrain in best way possible with effective technique selection and visa-versa using the best efficient/productive technique for every topographical feature)
- During uphills, researchers identified that diagonal stride speed is increased by using longer cycles (Zoppirolli et al., 2018); in steep hills there were shorter cycle lengths and more rapid cycle rate, also supported Pellegrini et al., 2011 and Stöggl et al., 2018 who measured the relationship of cycle rate to incline.
- Various moments within race of different use (i.e., to accelerate from start - shorter cycle length and rapid cycle rate; middle of course on flat terrain - slower cycle rate; finish straightaway – higher speeds attained by rapid cycle rate while keeping long cycle length) (supported by Marsland et al., 2021)
- Drafting/following others closely (i.e., adjusting to their movement patterns to follow efficiently and/or conserve energy for individual race strategy)
- Perceptions in upper body versus lower body and adjusting or adapting cadences accordingly (in upper versus lower limbs) as well as technique to find optimal rhythms and pacing based on overall feeling of exertion and limits
- Environmental factors including terrain topography, snow conditions, ski speed, wind, temperature, etc.
Figure obtained from Sandbakk, et al. (2010)
Of note is that some of these factors have been shown to vary by gender due to influences of body composition and energy utilization, body size, anaerobic/aerobic power, utilization of maximal oxygen update, upper body strength, race pacing strategies, and efficiency (Sandbakk et al, 2017b).
It is important to practice and train regularly with varying rhythms/cadences, in other words changing the cycle rate. The idea is to play with different rates to find your preferred or optimal cadences for various conditions within each sub-technique to develop your ability to ski well and efficiently with difference cadences. This will allow you to adapt to differing terrain topography, body feelings, snow conditions/ski speed, while giving you the ability to control and adjust your pacing strategies, and the ability to initiate and/or adapt to tactical interactions.
Ideas for how to train this concept?
- Drills
- cadence focused moving from fast, to faster, to fastest
- transitioning between sub-techniques at various speeds in a given terrain, working on making the transition effectively as well as the speed of the transition
- § example, when approaching a hill and switching to V1 skate, rather push into the hill with a higher cadence of your current technique (V2 in this case) and make an efficient but rapid technique change to V1, play with what works for you regarding technique but also at different speeds
- Strides (i.e., short 10-30 seconds of gradually increasing speed with cycle length; gradually increasing speed with cadence/cycle rate - amongst different terrain sections with each sub-technique)
- Follow the leader with teammates/groups (in various terrain with each sub-technique) - as there are higher speeds attained when skiing in a group (Marsland et al., 2021)
how to:
- mimic cadences
- overtake/pass with different cadences
- make an attack
- respond to an attack
- Speed play (find where to focus within your body/mind on cues to make your technique match your cadence)
- Play with the placement of your center of mass (body position) at different speeds in each terrain with each sub-technique (not only the common cues of ‘hips forward’, but also think of elbow and ankle angles)
- Find ways to: lengthen your cycle, rapidly produce force (leg push off in skating vs. pole plant in double poling, we want a quick transfer of power throughout body)
- Keeping your head up and looking forward during diagonal stride, herringbone, and skating techniques. This will help keep your upper body aligned with a good center of mass position and reduce the forward hinge position that often occurs as we get tired (keep head up and look up the hill, especially important when fatigued)
- When tired/fatigued (i.e., your technique is changing and you are getting bogged down), train yourself in these moments to adjust to a little quicker cadence and reduced cycle length while focusing to maintain forward leaning position. In my opinion and experience, this adjustment will help maintain your speed while placing less workload on your muscles/physical capacities (as with all things, you need to train this). An easy example for visualization, when you are diagonal striding and you do not have enough kick wax to maintain a long stride – you shorten your stride and take smaller steps to maintain your body position as well as your speed into/throughout the hill. The idea is to train yourself to make similar and small adjustments using any sub-technique when your physical condition or environmental condition requires.