The bench press is one of the most popular and widely used exercises for building upper body strength, particularly in the chest, shoulders, and triceps. However, there is ongoing debate about how best to perform this exercise to maximise its effectiveness.
One major point of contention is whether fast or slow repetitions on the bench press are better for reaching fitness goals, such as muscle growth (hypertrophy), strength gains, or endurance. This article will delve into the science behind fast and slow reps, their benefits, and the optimal approach based on specific fitness goals.
Understanding Repetition Speed: What Are Fast and Slow Reps?
When performing a bench press, the speed at which you lower (eccentric phase) and lift (concentric phase) the barbell determines the rep speed. Fast reps typically involve explosive movements, with the concentric phase executed as quickly as possible. Slow reps, on the other hand, are characterised by a controlled movement, often lasting 3–6 seconds during both the eccentric and concentric phases.
Repetition speed plays a critical role in the type of muscular adaptations that occur. The primary factor is the time under tension (TUT)—the duration that the muscles are engaged during the exercise. Different speeds of reps place varying levels of demand on your muscles, affecting outcomes such as hypertrophy, strength, and endurance.
The Science Behind Fast Reps
Fast reps, particularly those performed with explosive concentric movement, are often favoured for developing power and strength. Fast twitch muscle fibres (Type II) are primarily activated during rapid, forceful movements. These muscle fibres are larger, capable of producing more force, and can lead to greater strength gains when trained properly.
In a study published in the Journal of Strength and Conditioning Research, it was found that lifting at a faster tempo increased power output during resistance training exercises, including the bench press (Sakamoto & Sinclair, 2012). By focusing on fast, explosive movements, individuals can stimulate their fast twitch fibres, which are vital for improving strength and power.
However, the downside of fast reps is that they typically reduce time under tension, which may limit hypertrophic adaptations if not balanced with other training methods. A study by Davies et al. (2017) found that fast reps may not be as effective for muscle growth as slower reps due to a shorter time under tension, which is crucial for inducing microtrauma and stimulating muscle repair and growth.
The Science Behind Slow Reps
Slow reps emphasise control throughout the entire movement, particularly in the eccentric phase, where muscles lengthen under load. This increased time under tension has been associated with greater muscle damage, a key factor in muscle hypertrophy.
Research published in the European Journal of Applied Physiology found that slow reps resulted in a more significant increase in muscle cross-sectional area compared to fast reps due to the prolonged time under tension and greater muscle fibre recruitment during the eccentric phase (Schoenfeld et al., 2015). The study concluded that slow reps can be highly effective for those whose primary goal is muscle hypertrophy.
Moreover, slow reps may improve muscular endurance by enhancing the capacity of slow twitch muscle fibres (Type I), which are more fatigue-resistant. This can be beneficial for athletes and individuals seeking to improve muscular endurance alongside strength.
Fast Reps vs Slow Reps: Which is Better for Hypertrophy?
Muscle hypertrophy is the growth of muscle tissue, and the bench press is a cornerstone exercise for individuals aiming to increase the size of their chest and triceps. The debate between fast and slow reps becomes particularly relevant when hypertrophy is the primary goal.
Slow Reps for Hypertrophy
As mentioned earlier, slow reps excel at providing a greater time under tension, which is essential for hypertrophy. Time under tension allows for more mechanical stress on the muscle fibres, causing microscopic tears. These tears, when repaired, result in muscle growth.
In a review by Schoenfeld et al. (2010), the authors found that performing exercises with a slower tempo (around 2–6 seconds per repetition) resulted in greater hypertrophy compared to faster tempos. The prolonged eccentric phase of slow reps creates higher levels of muscle damage, which is necessary for optimal muscle growth.
Fast Reps for Hypertrophy
Fast reps, while not as effective at maximising time under tension, can still contribute to hypertrophy when used strategically. A study by Villanueva et al. (2015) found that combining fast reps with slower reps in the same workout can lead to significant hypertrophic gains. This mixed approach allows individuals to benefit from the explosive power development of fast reps while also increasing time under tension during slower, controlled reps.
In summary, slow reps are generally superior for hypertrophy due to the increased time under tension and muscle damage. However, incorporating fast reps can complement a hypertrophy-focused programme by targeting different muscle fibres and improving strength.
Fast Reps vs Slow Reps: Which is Better for Strength?
Strength training focuses on increasing the maximum amount of force that muscles can produce. For the bench press, this involves lifting heavier weights, usually in the range of 1–5 repetitions per set.
Fast Reps for Strength
Fast reps are particularly advantageous for building strength because they allow for the recruitment of fast twitch muscle fibres, which are responsible for generating high levels of force. Explosive reps can increase neuromuscular efficiency, allowing you to lift heavier weights over time.
Research in the Journal of Sports Sciences demonstrated that lifting with a faster tempo (specifically during the concentric phase) improved maximal strength gains compared to slower tempos (Harris et al., 2016). Fast reps enable lifters to generate more force during the concentric phase of the bench press, leading to more significant strength adaptations.
Additionally, fast reps allow for heavier loads, which is a key driver of strength development. Powerlifters and strength athletes frequently use fast reps in their training programmes, often accompanied by low repetition ranges and near-maximal loads.
Slow Reps for Strength
While fast reps are commonly associated with strength training, slow reps can also contribute to strength gains, albeit in a different way. By increasing time under tension and focusing on the eccentric phase, slow reps can improve muscle fibre recruitment and tendon strength, which are essential for injury prevention and long-term progress.
However, due to the lower loads typically used during slow reps, they may not be as effective for maximal strength development as fast, heavy reps. A study by Gonzalez-Badillo et al. (2014) found that slow reps, while beneficial for hypertrophy, did not produce the same strength gains as fast, explosive repetitions when heavier loads were used.
Fast Reps vs Slow Reps: Which is Better for Muscular Endurance?
Muscular endurance refers to the ability of a muscle or group of muscles to sustain repeated contractions over time. It is especially important for athletes in endurance sports or those looking to improve stamina during high-repetition exercises.
Slow Reps for Endurance
Slow reps are highly effective for developing muscular endurance due to the increased time under tension. Prolonging the eccentric and concentric phases of the bench press forces muscles to work harder for longer periods, enhancing their capacity to resist fatigue.
A study published in the Journal of Applied Physiology found that slower repetitions were more effective at improving local muscular endurance compared to faster reps, as the prolonged time under tension led to adaptations in slow twitch muscle fibres (Jones et al., 2013). These fibres are more fatigue-resistant and are activated during longer, sustained efforts.
Fast Reps for Endurance
Fast reps can still play a role in endurance training, particularly when combined with circuit training or high-intensity interval training (HIIT). By performing fast reps in a circuit, individuals can enhance their cardiovascular endurance while still targeting the fast twitch fibres responsible for power and strength. However, for pure muscular endurance in the bench press, slow reps are generally more effective.
Combining Fast and Slow Reps for Optimal Results
The question of whether fast or slow reps are better for the bench press is not an either-or proposition. Both types of repetitions have unique benefits that can be leveraged based on individual fitness goals. Incorporating a combination of fast and slow reps into your training programme allows you to capitalise on the advantages of both, leading to more well-rounded results.
For example, if your primary goal is hypertrophy, you could perform slow reps with lighter to moderate weights to maximise time under tension and then finish with fast, explosive reps to stimulate fast twitch muscle fibres. If strength is your goal, prioritise fast reps with heavier weights while integrating slow reps to improve muscle control and endurance.
Periodisation: A Strategic Approach
Many strength and conditioning experts recommend periodisation, a training strategy that involves cycling between different phases of training to target specific goals. For instance, a hypertrophy-focused phase may include slow reps for higher time under tension, while a strength phase would emphasise fast reps with heavier loads.
A study by Rhea et al. (2002) supports the effectiveness of periodisation in resistance training. The researchers found that individuals who used a periodised approach, alternating between fast and slow reps, saw greater gains in both strength and hypertrophy compared to those who followed a non-periodised programme.
Conclusion: Which Repetition Speed Is Right for You?
Ultimately, the decision between fast and slow reps on the bench press depends on your specific fitness goals. For hypertrophy, slow reps with greater time under tension are generally more effective. For strength, fast reps that target fast twitch fibres and allow for heavier loads should be prioritised. For endurance, slow reps excel due to their focus on sustained muscle engagement. However, a well-rounded training programme that incorporates both fast and slow reps is likely to yield the best overall results.
By understanding the benefits of each approach, you can optimise your bench press routine to match your personal fitness objectives.
