Originally Posted by CTKook
You may want to reflect on the implications of what you just said.
"...the aerobic physical demands of DH mountain biking are similar to sports such as: hockey, basketball, racquetball, and noncompetitive XC skiing...[t]he fact that this appears to be a full-body type of exercise...could have important benefits for promotoing health, particularly metabolic health given the aerobic-anaerobic engagement of an apparently large muscle mass.. ." https://www.researchgate.net/publication/231740130_Physiological_demands_of_downhill_mountain_biking
The fact that you may not pedal for much of a run doesn't mean you're not working. This is again a case where getting to a pump track could give a lot of good practical learning.
You do realize Hockey is considered an anaerobic sport right? ....they ONLY reason there is an aerobic component is the duration (e.g. recovery between shifts....no such need for ski racing). Average shift length for an elite hockey player is ~30s.
The link you posted also used recreational athletes that rode on at their typical skill level on participant selected tracks that were about a 9min lap. (8.8min+/-2.4min). How many alpine ski races do you know that take 9mins? I know none. While the participants aerobic system was taxed (9mins....no surprise) the fact there was also significant increase in forearm fatigue (decreased dynometer results) post lap demonstrated significant muscular fatigue over the run (requiring further study to determine the muscular demands).....sounds similar to the jelly legs one gets after bombing down a run at high intensity.
I mentioned similar but not exact because typical elite level mountain biking races last 3-4mins, while alpine ski races last sub 2mins. So from a purely energy demand they would differ (e.g. mountain bike would require greater demand from the aerobic system).
"Downhill performance relies on riders’ technical ability and high levels of concentration and decision-making, however, the explosive injections of power necessary to create and sustain speed should not be overlooked as an important aspect of performance and thus the sport has been termed as an ‘intermittent sprint sport’ by British Cycling"
"a review article by Impellizzeri and Marcora (2007), gives some values collected from the Italian National Downhill team. The lower VO2max (63.2 mlkg-1min-1) suggests that aerobic fitness may be of less importance to Downhill cyclists than for XC cyclists. This seems logical due to the shorter duration, intermittent and descending nature of DH" More research required however.
"only one study to date, examines the exercise intensity of Downhill mountain biking. Hurst and Atkins (2006) investigated seventeen National level male Downhill cyclists whilst they performed two runs of a measured Downhill course...........the isometric contractions required to absorb the terrain could account for this stable and elevated HR. Another explanation may be that the time between efforts is too short for the cardiopulmonary system to recover following elevations in response to the intermittent efforts, resulting in the elevated HR profile.....Monitoring blood lactate parameters for the shorter duration DH discipline are less likely to provide useful information for the coach and athlete (and to date have not been reported). DH is a short duration, intermittent discipline. For not only logistical but for physiological reasons, i.e. the around 30 s transient time for blood lactate to appear in the blood following anaerobic bursts of work, obtaining blood lactate samples during a DH run would likely be of little worth. Furthermore, taking a lactate sample at the end of the run would not be representative of the whole performance load, thus lactate sampling may not be of use in DH field testing."
"Downhill Mountain biking, as mentioned, is a high intensity intermittent cycling discipline (Hurst and Atkins, 2006), which can be assumed, would place a higher emphasis on the ability to generate very high power outputs (anaerobic system) rather than the aerobic system" Of course limited research limits available data....and the nature of DH (doesn't use crank much) also limits ability to collect data.
However some good indications that the start is vary comparable to bobsled, luge, skeleton (and I'd stretch to alpine skiing) as indicative of relative power demands but also eventual performance. (faster start requires greater POWER, and higher velocity resulting in higher probability of better finish times).
"Laboratory-based testing of Downhill mountain bike athletes identified a number of interesting findings. Downhill specialists can produce very high PPO during short-duration maximal sprint cycling (1839 ± 261 W/ 23.36 ± 2.12 Wkg-1) when compared to healthy males and cyclists from endurance-based cycling disciplines (Weyand et al., 2005; Baron 2001; Gaitanos et al., 1993; Davies et al., 1980, 1989; Sargeant et al., 1981) and sprint cycling (Craig and Norton, 2001; de Koning et al., 1999; Davies et al 1980). Relationships identified between athlete power profiles and their anthropometric characteristics suggest the ability of the Downhill athletes to produce great peak powers is influenced by their somatotype with the more mesophorphic individuals producing the greatest powers. More specifically, a positive correlation is seen between PPO and thigh girth (r = 0.84). This could be due to a greater number or size of muscle fibres within the upper leg muscles, which enables the greater generation of power. Downhill mountain biking is characterised by British Cycling as an intermittent sprint sport and the ability to generate speed quickly during the short periods of pedalling (~ 5-s) (Hurst and Atkins, 2006) may be an influential factor on performance time. An optimal cadence for producing PPO was identified as between 100 – 120 rpm (106 rpm) which is in agreement with a number of other studies (Baron, 2001; MacIntosh et al., 2000; McCartney et al., 1983; Sargeant et al., 1981). Determining an optimal cadence for producing PPO may be particularly important for DH at the start of the race to allow them to select a gear that will help them attain the optimal cadence in the shortest time, allowing a power and fast start to the race. Furthermore, the present study, in the controlled laboratory setting, identified a relationship between peak power output (PPO) and time to peak power output (r = 0.77) during a 6s sprint, which tends to support the importance of fast power production in DH performance."
Nobody is suggesting that the lack of pedaling means no work (you took it there yourself), it's like saying a full tuck down the hill on skis takes no work....it does. It was stated to suggest the AEROBIC component might not be as important as you suggest. E.g. Strength, power and anaerobic factors being more dominant. Again, I'm not saying one shouldn't do aerobic exercise....but to suggest or make assertion that it's very important to skiing while weight lifting has little to no value, power is meaningless, etc. is incorrect.
Again (as posted before) the energy system used is highly dependent on how hard one pushes....if you are just easy cruising sure it's not taxing to the system and will use predominately aerobic systems....however to suggest skiing is aerobic purely on this premis without considering the requirements and demands of elite skiers is uninformed from my perspective. (especially given the continuous comments and responses to suggest those athlete demands and resultant training requirements are not valuable to skiing in general.)
Hopefully you realize there are many "recreational" skier types....those that would fall into the easy cruise catagory, and many that also fall into closer to the requirements of the more elite skier.