This is not a lesson in semantics; there is a very important concept here regarding the development of skills and athleticism among young hockey players.

The phrase 'anaerobic training’ is often equated with 'anaerobic metabolism,' and the terms are not interchangeable.  The other day, a fitness instructor on TV incorrectly explained that when a person is working anaerobically, he/she is no longer using oxygen.  Let's hope the workout doesn't last long, or the athlete would obviously suffocate.  The fact is, anaerobic workouts can be highly aerobic - - more aerobic than aerobic workouts, for that matter.

To understand this we need to know the basic terms.  First, metabolism (in this case) means the chemical conversion of dietary fuels to energy to be used for muscle contraction.  Muscle cells 'burn' fuels like glucose (sugar), fat, protein, and even lactate (one of the products of anaerobic metabolism).  The word aerobic literally means with oxygen.  Aerobic metabolism occurs when energy is supplied by combining oxygen with dietary fuels.  Typical aerobic training (long, slow distances like jogging) is done at a slow pace so that oxygen can be supplied to working muscles fast enough to match the need.

Anaerobic metabolism is the chemical breakdown of fuels without oxygen, and this is required when the muscles are working so hard that oxygen cannot be supplied fast enough.  Technically speaking, the only way exercise could be totally anaerobic is if the person were not allowed to breathe.  In reality, during normal anaerobic workouts there is a huge aerobic component - - breathing is often much heavier than during aerobic workouts, the heart is pumping at (near)-maximum rates, and muscles are being supplied with a lot of oxygen.  But the delivery of oxygen is inadequate to match the elevated workload, so anaerobic metabolism must also contribute to the energy production.  How much it contributes depends on the intensity and length of the work intervals, the length of the rest, and the ratio of work to rest.

Therefore, anaerobic training uses both the aerobic and anaerobic metabolic pathways.  It also challenges - - and therefore trains - - the cardiovascular system.  So, when fitness instructors refer to 'cardio' workouts, as if they must be aerobic, they are wrong.  It is also incorrect to claim that aerobic workouts are the best way to increase aerobic capacity.  For old duffers like this author, long, slow distance workouts are the safest way to increase cardiovascular fitness.  But for young hockey players, much of the endurance training should be anaerobic intervals, which also elevate the comfort zone for competition and increase speed, power, skill, and explosiveness.

By training aerobically (long, slow distances) there is no improvement in speed, explosiveness, or power.  Furthermore, training at an aerobic pace on the ice would establish a slow comfort zone which is more than just a habit.  There are definite physiological consequences when one tries to compete at a faster pace than practice.

So, what's the point?  Without skating speed, quickness, and agility, no one makes it to the highest levels of hockey, and this requires hours and hours of training - - on the ice and off - - using quality intervals. The good news is that you can also gain aerobic endurance and cardiovascular efficiency as a byproduct of this training.  We tested a college men's hockey team before and after six weeks of dryland interval training designed to improve running speed and quickness, anaerobic power on hills, and explosive power using skating-specific squat jumps.  The training included short sprint intervals (5-15 seconds work : 50-60 seconds rest) and longer intervals for anaerobic power and endurance (30:60 and 30:90).  There was no aerobic distance training. Workouts lasted only 45 minutes in the first week and increased to 90 minutes by the sixth week.

Post-tests showed significant improvements in skating quickness even though none of the training was on-ice.  There were also improvements in power, measured during two anaerobic bicycle tests (12-second sprint test improved 6.8%; 40-second all-out Wingate test improved 8.0%). But the greatest percentage improvements were apparent during a graded exercise test to measure changes in cardio-respiratory parameters normally associated with aerobic training. Total work done during the graded exercise test increased by 29%. This, of course, measures a combination of aerobic and anaerobic work.

Anaerobic threshold was elevated by 20%, and VO2 max increased 6.3%.  In a separate 5km run, subjects improved their times by 5.5%, and no one ran distances during the training period. Cardiovascular parameters also improved.  One indication of successful endurance training is that the heart rate is lower at any given workload, indicating the stroke volume has increased.  In other words, after a six-week training program the heart pumps more blood per beat, so it doesn't have to beat as fast.

For this team, the heart rates were lower at every workload after training six weeks (post-testing).  This is shown on the graph.  Furthermore, the elapsed time until the heart rate reached 85% of its maximum was extended by 5.5%.  Similar results were reported by scientists in a separate study (Fox et.al. Med.Sci.Sports Exerc. pp.18-22. 1973).

The message is clear. You do not have to train aerobically to gain cardiovascular and respiratory fitness, because anaerobic training can have a tremendously high component of aerobic metabolism along with the various anaerobic pathways supplying energy to the muscles.

Hockey is an interval game, so the most important endurance training is interval workouts on-ice. During games, shifts on the ice are typically about 40 seconds long, and rest intervals on the bench are 2 to 3 times as long if there are no face-offs.  Biomechanists analyzed high-speed film to determine that a typical 40-second shift will have a series of short (3-second) bursts of acceleration and deceleration.  Furthermore, research has verified what hockey players feel each year at training camp: endurance training off-ice may not increase endurance on-ice (Daub et.al. Med.Sci.Sports Exerc. pp. 290-294. 1983).

The Bottom Line
At a young age when it is still possible to make significant improvements in skating skill, speed, quickness, and agility, it is important to spend most of your time training for these goals (along with other hockey skills).  Whether skating, sprinting, jumping, or lifting weights, the anaerobic interval training needs to be very intense, much greater energy output than the pace of an aerobic workout.

The good news is you can have your cake and eat it, too.  If you plan the anaerobic workouts wisely there will be significant improvements in cardiovascular and respiratory fitness without the need to jog or bike distances.