The two-time Tour de France stage winner lies six seconds down on race leader Julien Vermote (Etixx-Quickstep), with the next GC contender almost a minute further back.
Friday's stage sees the race climb it's only true summit finish with the slopes of Haytor providing the climbers with the chance to win the stage and move up the overall. Saturday is s split stage with a 15km individual time trial in the morning followed by a tough hilly circuit race later in the afternoon.
"We've got to be attentive at the start of the race and then I'll go full gas on the climb… in the best way possible," Cummings told Cyclingnews when he was asked to look ahead to the Haytor stage.
"Every day you need to give it everything with these tricky little finishes. If you win or lose a few seconds on one stage that can win or lose you the race."
Seconds are indeed important in a race such as the Tour of Britain. Tony Gallopin (Lotto Soudal) fought tooth and nail for five seconds in time bonuses on stage 4, all just to move himself one place up the overall, while Tom Dumoulin sits at 1:18 and will be itching to blow the opposition away in the time trial.
Vermote is the unknown quantity. He beat Cummings to the win and the race lead on stage 2 and is clearly riding well. He was also a U23 Belgian national time trial champions, so is no slouch when racing against the clock.
"I just go day-by-day and then we can look at the GC in the evening but it doesn't really change much because I'd still go full gas in the time trial anyway," Cummings said when asked if he would ride for GC on the climb to Haytor or for the stage.
Cummings' strategy on the tough final climb will be decisive. Vermote has his teammate, Daniel Martin at 1:04, and the Irishman is one of the strongest climbers in the race. With so many potential threats Cummings will need to measure his effort and the position he now find himself in is a million miles away from the long-range breaks he has specialised in over the last few seasons. He is a rider, after all, who although has not targeted them in the past, has only one won stage race during his long career.
"I'll have to be smart and ride off other people a lot. I've ridden well on a hilltop finishes before so we'll just see how it goes. If I feel good then I think I can limit my loses. There are better climbers than me but if I can limit my loses on the climb and then hold my own in the time trial then I have a chance."