I crafted this during my university years, and I believe its relevance persists today.
The concept of cross training emerged in the 1980s alongside the introduction of triathlons. During this period, numerous athletes specializing in individual sports noticed impressive performance in their prior specialized events despite reducing specific training in favor of multi-event training (Foster et al., 1995).
Cross training operates by either preserving or enhancing the existing training stress. This stimulus contributes to maintaining the adaptations achieved through sport-specific training for running. As cross training encompasses various non-specific modalities, it safeguards both general peripheral and central adaptations.
Training adaptations can be categorized as peripheral and central. The periphery refers to the exchange of cardiorespiratory elements between blood and muscles. This entails adaptations such as reduced blood lactate buildup, heightened aerobic capacity, enhanced enzyme efficiency, increased mitochondrial density, and angiogenesis. Central cardiovascular adaptations include decreased heart rate, elevated red blood cell count, heightened blood plasma content (which reduces blood viscosity), and increased cardiac output (stroke volume).
Foster et al. (1995) found that diverse cross training, such as swimming, enhanced running performance when compared to an exclusive running-focused program of similar intensity. While gains were less pronounced than in the running-only group, this hints at maintaining fitness during extended injury periods.
Similarly, Costill et al. (1988) demonstrated that substituting swimming for running maintained trained runners' VO2 max and increased their swimming VO2 max by 10%.
White et al. (2003) supported these findings, showing that female distance runners replacing 50% of their running volume with cycling at around 70% VO2 max preserved aerobic performance during recovery between cross-country and track seasons, akin to primary running.
Silvers et al. (2007) emphasized differences between deep water and land running, underscoring distinct lower extremity muscle usage and kinematics due to ground absence and water resistance. Activities mimicking cardiovascular engagement provide better long-term peripheral adaptations. For valuable insights, turn to the respected running coach and exercise physiologist, Jack Daniels. This is amazing.
Championing Cross Training Insights from the Legendary Coach John MacDonnell
In the words of John MacDonnell, the most successful coach in NCAA history:
"Injuries sometimes necessitated cross training. I could recount tales of the swimming pool. Gary Taylor injured his knee fooling around in his apartment during cross country season, so we had him in the pool twice a day, doing pool intervals. Three weeks before his first indoor meet, he asked if he should run. Feeling great, I suggested two sets of 200s. He complied and clocked 3:58 for the mile in his first indoor meet, a personal best. His cardiovascular conditioning was solely swimming-based. Various athletes, including Daniel Lincoln, Alistair Craig, Joe Falcon, and Frank O'Mara, joined him in the pool. We would do sets like 40 x 30 seconds with 30 seconds recovery or 40 x 1 minute, even 20 x 2 minutes. I've never seen athletes emerge from a pool in better cardiovascular shape. Surface contact is the only missing element, which can be addressed through a few weeks of jogging."
This quote is extracted from John MacDonnell's book (available at the studio if your interested). He achieved unparalleled success, coaching 54 individual NCAA champions and 24 Olympians with his dominant Arkansas Razorbacks.
By now, I trust I have effectively showcased the potency of cross training during periods of injury. This discussion primarily approaches the subject from a physiological standpoint, while the psychological benefits are boundless. Not only do athletes uphold a positive self-efficacy, but they also channel their energies into constructive activities. It's crucial to monitor training stress, adhere to sound principles, and exercise caution when transitioning back to running.