Cycling

With the advent of “Spin Classes” stationary cycling can actually be quite fun. If you are training on your own you might have to be creative to prevent stationary burnout. High quality stationary cycle trainers are getting cheaper like the one below by Stamina. Another option is to use a wind trainer - which you mount your current bike to for a great stationary workout.
Road or mountain biking
are great ways to enjoy the outdoors but if you are not accustomed
to this type of training it may be more difficult to maintain a target
training level. A heart rate monitor can be helpful to stay in the
training range you are shooting for. Cycling does not challenge your heart rate as much as running will so if you are not using a heart rate monitor you will need to go a little harder to get the same cardiovascular workout.
If you are recovering from injury, consider keeping resistance lighter to avoid strain on the knees. Seat position should be such that your knee is slightly bent when the foot is at the furthest point of the down stroke. Try to keep the knees in line with the feet; a slight circular deviation is normal. Cadence should be between 70 and 90 revolutions per minute depending on your cycling experience.
Stationary cycling can allow you to decrease your running distance during
a recovery period and maintain fitness. Researchers conducted a study
on collegiate female cross-country runners during their recuperative
phase of training. The “run training” group continued
their weekly running volume at a decreased intensity. The “cycle
training” group decreased their mileage 50% and cycled for
the equivalent amount of time and at the same reduced intensity.
After five weeks both groups performed a 3,000 meter run. The “run
training” group slowed 9 seconds and the “cycle training” group
slowed 22 seconds. The ability to use oxygen (VO2 Max) was unchanged
between the groups. The time difference between the two groups was
small enough that the researchers concluded that cycling could be
an effective mode of training during the recuperative phase, especially
when the benefit of reduced muscle and bone strain is considered.
If your body doesn’t tolerate additional run training then
supplemental cycle training can provide improvements similar to additional
running. Researchers at Purdue University reported that well trained
runners improved their 5K times by supplementing their running program
with vigorous cycling. Participants in the experimental group maintained
their current running program and added two sessions of intervals
performed on a stationary cycle and one session of moderate cycling
for sixty minutes. After six weeks of supplemental training (additional
running or cycling) both groups had similar improvements in 5K performances.
