Training Load Explained: CTL, ATL, TSB & Optimal Range

Q: What is a good weekly training load?

There is no universal number - a good load is relative to what your body is adapted to. A rider with a CTL of 50 is well served by 350-420 TSS per week, while the same load would detrain a rider holding a CTL of 90. The practical rule: keep weekly load close to your recent 6-week average, nudging it up gradually in build weeks and cutting it 40-50% in recovery weeks.

Q: How quickly can I increase my training load?

A safe ramp rate is about 3-5 CTL points per week (roughly 20-35 extra TSS per week, sustained). Ramping faster than 7-8 points per week sharply raises the risk of overtraining, illness, and injury. The acute:chronic workload ratio tells the same story: keep your last 7 days of load within about 0.8-1.3x of your 28-day average.

Q: What is the difference between training load and TSS?

TSS scores a single ride; training load is the accumulation of those scores over time. FormBeat sums TSS per week for weekly training load, and smooths daily TSS into CTL (42-day average, your fitness) and ATL (7-day average, your fatigue). The difference between them, TSB, indicates your form on any given day.

Q: What happens if my training load is too high?

Short spikes cause functional overreaching - heavy legs and flat power for a few days, fixed by rest. Sustained excessive load leads to non-functional overreaching or overtraining: declining performance despite hard work, elevated resting heart rate, poor sleep, irritability, and frequent illness. Recovery can take weeks to months, which is why managing load proactively beats digging out of a hole.

Training Load represents the accumulated Training Stress Score from activities in a given week. It is a great way to see how hard you have trained each week.

Besides your measured training load, FormBeat will calculate your optimal training load range for each week, which is based on your past training. Training in the optimal range will help you maintain and improve your overall fitness.

Weekly Training Load Estimator

Enter your average weekly TSS from the last 4-6 weeks to get rule-of-thumb ranges for your next weeks.

Average weekly TSS

Acute vs Chronic Load: CTL, ATL, and TSB

Weekly totals are the simple view. Underneath, training load is tracked as two rolling averages of your daily TSS that decay at different speeds:

CTL (Chronic Training Load) - a ~42-day weighted average. This is your fitness : the work your body has absorbed and adapted to. It moves slowly, which is the point.
ATL (Acute Training Load) - a ~7-day weighted average. This is your fatigue: it spikes after big days and fades within a week of easy riding.
TSB (Training Stress Balance) - CTL minus ATL, your form. Negative TSB means you're carrying fatigue (normal in a build); positive TSB means you're fresh (what you want on race day).

The art of training is pushing ATL high enough, for long enough, to drag CTL upward - without letting the gap become so large that you break down instead of adapting.

How Fast Can You Ramp?

The most useful guardrail is the ramp rate: how many CTL points you add per week. Around 3-5 CTL per week is sustainable for most riders; 5-7 is aggressive and best kept short; beyond 8 the risk of illness, injury, and non-functional overreaching rises sharply. A related lens is the acute:chronic workload ratio (ACWR) - your last 7 days of load divided by the last 28. Keeping it between roughly 0.8 and 1.3 is the sweet spot; above 1.5 is the danger zone where injury risk climbs fastest.

Two quieter saboteurs are worth knowing. Monotony - doing nearly the same load every day - raises strain even at moderate volumes; hard days and genuinely easy days beat a grey middle. And chronically low load is a risk of its own: ramping into a big event from too small a base is how underprepared athletes get hurt.

Reading Your Training Load Week to Week

A practical weekly rhythm for self-coached riders:

Build weeks (2-3 in a row) - weekly TSS slightly above your recent average, nudging CTL up a few points.
Recovery week (every 3rd-4th) - cut volume to 50-60%. Fitness barely drops; fatigue clears; adaptation lands.
Before key events - taper load so TSB climbs positive while CTL stays high: fit and fresh.

Warning signs that load has outrun recovery: declining power at the same effort, elevated morning heart rate, poor sleep, irritability, and dreading workouts you normally enjoy. Two or more of those for several days is your cue for an early recovery week - not a harder one.

Your Optimal Range, Computed for You

Generic rules of thumb only go so far - the right load depends on your history, your recovery, and how your fitness is trending. FormBeat draws your personal optimal training load band on the weekly chart (the image at the top of this page), recalculated every week from your actual riding. Stay in the band and fitness builds sustainably; the chart makes it obvious when a week ran too big or too small, and the training status reads the trend for you.

Know your optimal load every week

FormBeat computes your personal training load range from your real riding - then tells you each morning whether to push, hold, or recover.

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