Interval Training and Its Placement in Strength Workouts

Interval training is a type of training that alternates between high-intensity bouts of exercise and low-intensity recovery or rest periods. In my opinion, incorporating interval training into your strength workouts is the most effective and efficient method of concurrent training for cardiovascular fitness & lean body mass development, especially in the context of a 60-minute personal training session. It’s also extremely convenient if you do not have the ability to devote the time for multiple separate strength & conditioning workouts.

Integrating interval training alongside strength training combines the best of both worlds, simultaneously improving cardiovascular fitness, muscular strength & hypertrophy, as well as increasing fat burn, and improving overall work capacity. However, the placement of the interval training – whether at the beginning, middle, or end of a strength workout – can influence the adaptations and outcomes. Let’s explore the benefits and various training adaptations of each scenario.

1. Interval Training at the Beginning of a Strength Workout

The Benefits:

• Priming the Body: Starting with interval training can act as an extended warm-up, increasing heart rate, core body temperature, and enhancing blood flow to muscles.

• Maximal Effort: Engaging in conditioning first can allow athletes to reach higher intensities, and exhibit a higher amount of effort, considering the muscles are fresh. Increased effort and output could potentially improve cardiovascular adaptations.

• Mental Preparedness: Tackling the toughest cardio segment first not only sets a positive tone for the rest of the workout but also fortifies mental resolve. By navigating through the hardest part upfront, clients often feel a sense of relief and confidence, aware that they’ve overcome the most demanding segment of the session.

Adaptations:

• Improved Cardiovascular Fitness: With minimal fatigue, and fresh muscles, clients will be able to exhibit maximal effort during the interval portion of the workout, which can challenge the cardiovascular system more effectively.

• Enhanced Fat Utilization: Given the intensive nature of interval training, the body might access fat reserves sooner during the strength session, especially if the vigorous conditioning segment has depleted readily available energy substrates and muscle glycogen.

• Enhanced Opportunity for Motor Skill Development: Starting with cardio means muscles and the nervous system are already somewhat taxed when transitioning to the strength component. This could necessitate lighter weights and greater attention to form. This heightened focus on technique might stimulate greater neuroplasticity, fostering better retention and mastery of movement patterns.

2. Interval Training in the Middle of a Strength Workout

The Benefits:

• Strategic Structure: Incorporating the conditioning phase in the middle of the workout not only breaks the monotony but also provides a strategic distribution of energy and focus throughout the session.

• Optimized Intensity: By pre-fatiguing muscles with initial strength exercises, the subsequent interval phase can be approached with greater intentionality, maximizing the challenge and benefits of each set.

• Comprehensive Muscle Engagement: The initial strength phase, focusing on fast-twitch fiber activation, ensures that more slow-twitch fibers will have to participate in the interval section of the workout, leading to a holistic workout that targets a broader range of muscle fibers.

Adaptations:

• Enhanced Muscular Endurance: Over time, training in a pre-fatigued state challenges the body to adapt and perform under stress, potentially improving endurance during prolonged activities or events.

• Adaptive Energy Efficiency: Regularly practicing this structure can lead the body to fine-tune its energy expenditure and efficiency, better navigating the alternating demands of strength and cardio exercises.

• Neuro-Muscular Synchronization: Repeated exposure to varied fiber recruitment could foster improved coordination between the nervous system and muscles, fine-tuning movement patterns and boosting performance.

3. Interval Training at the End of a Strength Workout

The Benefits:

• The “Finisher” Effect: From a psychological standpoint, performing the conditioning at the end offers tangible benefits. Most clients, after completing the hardest part of the session, will depart with a profound sense of achievement. Exiting the session having expended all their energy not only validates their complete commitment but also ensures they perceive maximum value from their investment in the workout.

• Maximize Muscle Growth: Performing the conditioning at the end of the workout means strength exercises can be performed without pre-fatigue from intervals, potentially leading to better muscle strength & hypertrophy gains.

• Improves Recovery: Finishing with higher intensity intervals typically necessitates an enhanced cooldown period post-interval training. This can lead to faster lactate clearance.

Adaptations:

• Increased Afterburn: Performing the conditioning at the end, as a metabolic “finisher,” will ramp up the heart rate and increase calorie burn to complete the session. This environment is conducive to amplifying EPOC (Excess Post-exercise Oxygen Consumption). Intervals executed after the strength component may particularly elevate this afterburn effect, prolonging the benefits even after the session is over.

• Enhanced Anaerobic Capacity: When you engage in high-intensity intervals, especially after preceding strength training which might have fatigued some of your energy stores, the body is forced to rely more on anaerobic systems. The anaerobic energy system, specifically the anaerobic glycolytic system, is utilized during short bursts of intense activity, providing energy when oxygen is limited.

• Improved Mental Toughness: Pushing through intervals after a strenuous strength workout can be a mental challenge, potentially enhancing mental resilience.

Conclusion: